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Coast redwood and giant sequoia, two large tree species native to California, are finding a niche in the Northwest. People are planting them on small woodland properties, large private timber company lands, and in urban and suburban areas.
In their native ranges, giant sequoia (Sequoiadendron giganteum) grow exclusively within scattered groves on the west slope of California's Sierra Nevada mountain range, and redwood (Sequoia sempervirens) grow along the central and northern California coast, stretching into Oregon in the very southwest corner of the state (Figure 1).
This guide presents current research on the ecology, growth, management and wood products of these two increasingly popular tree species, highlighting information specific to Oregon where possible. It also includes considerations related to Oregon’s forest practice laws, cost-share and tax-deferral programs. Because of the native range of these two species, most of the research presented here comes from California.
Landowners in Oregon plant redwoods and giant sequoias for various reasons, including aesthetics, timber, biodiversity, conservation, adaptation to climate change and to experiment with new tree species. Whatever the reason for planting, landowners should understand the site conditions where the two species grow best, as well as their limitations.
In this publication, you will learn the many factors to consider before planting. For example, redwood and giant sequoia grow larger and faster than Oregon’s primary commercial tree species, Douglas-fir, but they are more heavily damaged by wildlife. Coast redwood resprouts prolifically, which means that once you plant coast redwood, you always have coast redwood!
If planting either giant sequoia and coast redwood after harvest, check to ensure they meet the reforestation requirements for Oregon’s forest practice laws. Note that log markets in Oregon could change. Currently, redwood and giant sequoia are not as widely accepted as other commercial conifers.
Whatever you decide, we hope this guide helps you make the best decision for your property and forest management goals.
Getting to know the trees: coast redwood
Coast redwood (Sequoia sempervirens, from here on referred to as redwood) is an evergreen conifer recognized by its characteristic red, thick, fibrous bark and its relative resistance to insect pests and pathogens. Redwood grows tall quickly in full sunlight, often 18 inches in the first year, and 2 to 6 feet per year for the first 10 years (Figure 2). The tallest redwood on record, a California specimen named Hyperion, has a confirmed height of 380 feet, as tall as a 37-story building! Heights at maturity of 240 feet are common, but they can exceed 300 feet (Figures 3, 4). Diameters commonly range between 6 and 15 feet.
Redwood’s historic range occupies a narrow strip approximately 450 miles long and 5 to 35 miles wide (Figure 8) in California and Southwest Oregon. Two groves on the Chetco River in the Siskiyou Mountains mark the northern boundary, 15 miles north of the California-Oregon border; the southern edge is marked by a grove in Salmon Creek Canyon in the Santa Lucia Mountains in south Monterey County, California. Redwood can be found within its range at elevations ranging from sea level to 3,000 feet. However, most stands occur from 100 to 2,320 feet.
Redwood naturally occurs on sites that experience both a maritime Mediterranean climate with cool and rainy winters and dry summers, and a temperate rainforest climate with heavy rain and moderate winter and summer temperatures. Across both climate types, temperatures average between 44˚ F (7°C) in the winter and 66˚F (19°C) in the summer; temperatures rarely fall below 15° F (negative 9°C) or rise above 100˚ F (38°C).
Precipitation, mostly winter rain, averages 70 inches (180 centimeters) across redwood’s range, with 90% falling between October and May. A heavy fog belt mitigates dry summers, and fog helps reduce drought stress, decreasing evapotranspiration and adding soil moisture from fog drip. (Fog drip involves condensation on the crowns of trees dripping to the ground and is especially pronounced in tall trees with large crowns.) However, beyond the fog belt, redwood is limited to areas of high moisture. The relationship between the fog belt and redwood distribution continues to be a topic of study.
Across its range, redwood can be found in pure stands, or associated with various forest types, such as:
- Mixed western redcedar (Thuja plicata), western hemlock (Tsuga heterophylla) and Douglas-fir (Pseudotsuga menziesii) forest.
- A mosaic of western redcedar, western hemlock, Douglas-fir and Oregon white oak (Quercus garryana) woodlands.
- Mediterranean California mixed evergreen forest: redwood, Douglas-fir, canyon live oak (Quercus chrysolepis), tanoak (Notholithocarpus densiflorus), Pacific madrone (Arbutus menziesii), California-laurel or Oregon-myrtle (Umbellularia californica) and golden chinkapin (Chrysolepis chrysophylla).
Redwood will dominate when growing with other trees and self-thin in denser stands (Figure 5). It tolerates heavy shade, although shading can reduce sprout height. Lower light levels and higher stand densities also limit diameter.
Redwoods have deep, wide-spreading lateral roots instead of a taproot. Even though redwood is a water-loving species, sustained periods of time submerged in water can lead to root disease, bark beetle activity and mortality — even in larger trees.
Reproductive structures — cones and seeds
Redwoods have oval or elliptical cones 0.75 to 1.25 inches in length (Figure 6) that produce seeds that are dispersed short distances by wind on average 200 to 400 feet from the parent tree. Redwood seed viability is low, and root and stump sprouting is the most usual form of reproduction.
Seedlings or clones
Redwood seedlings lack root hairs and are not efficient at drawing moisture from the soil. Access to water may be a limiting site factor, and late spring and early fall rains can be critical to survival. Seedlings grow rapidly in height, about 18 inches in the first season. See “Reforestation” for more information on redwood seedlings and clones.
Soils
Redwoods occur on deep, moist soils in the Inceptisol and Ultisol soil orders. Common parent materials are graywacke sandstones, shales and conglomerates found along alluvial fans, coastal plains and benches along large streams.
Fire regimes
Redwood fire regimes depend heavily upon associated plant communities and climatic/microclimatic and topographic site characteristics. For these reasons, mixed fire severity and frequency are seen across the range. The fire return interval (how often a fire occurs at a site over time) is between two and 87 years in redwood-dominated communities, with six to 25 years the most common interval.
Redwood has several fire-adapted traits. Its fibrous bark is up to a foot thick, which protects and insulates the delicate cambial layer from the heat of a fire (Figure 7). Redwood’s capacity for immense height and natural self-pruning of its lower limbs means that its crown can remain largely out of the reach of surface flames. If the tree is killed or damaged due to fire, trees can resprout from the stump, root crown and buds that lie just below the bark on the bole and branches. These sprouts contain the same genetic material as the mature tree.
Getting to know the trees: giant sequoia
Like redwood, giant sequoia (Sequoiadendron giganteum), sometimes called Sierra redwood, is an evergreen conifer in the cypress family (Cupressaceae). With an average diameter of 15 to 20 feet at maturity, giant sequoia is the only tree species with more biomass than redwood (Figures 9, 10). While larger in diameter, giant sequoias on average typically reach the same heights as redwoods, measuring an average 160 to 280 feet at maturity.
Giant sequoias have no permanent taproot, but they have large lateral roots. A single lateral root may grow as long as 300 feet toward the direction of a water source. These large roots support massive trunks, with red, fibrous bark up to 2 feet thick. Giant sequoia is generally intolerant of shade throughout all growth stages, with newly established seedlings being the most shade intolerant.
Giant sequoia’s native range (Figure 8) is restricted to 75 distinct groves comprising roughly 29,000 acres, along a limited area of the western Sierra Nevada, California, on land managed by private, public and Tribal entities. Groves range from approximately 2,470 acres with 20,000 large giant sequoias to small groves of only six living trees.
Giant sequoia occurs in elevations from 4,590 to 6,560 feet in the northern portion of its range and from 5,580 to 7,050 feet in the southern part. They prefer a montane-Mediterranean climate with wet, humid winters and dry summers. Mean daily maximum temperatures for July for typical groves are 75°F to 84°F (24°C to 29°C). Mean minimum temperatures for January vary from 21°F to 34°F (negative 6°C to 1°C), and year-round extremes range from about negative 12°F to 104°F (negative 24°C to 40°C).
Reproductive structures — cones and seeds
Giant sequoia’s barrel-shaped cones (Figure 11) measure from 1.75 to 2.67 inches (4.4 to 6.78 centimeters) and are persistent, meaning they can stay attached to a mature tree for 20 years or more and can even be aged by measuring annual growth rings. Mature trees can have anywhere from 10,000 to 30,000 cones at any given time. Giant sequoias have produced cones with viable seeds as early as 10 years. However, large cone crops with high seed viability usually only occur once the tree is 150 to 200 years old. At maturity, these persistent cones can release and disperse 300,000 to 400,000 seeds annually.
Most seeds are dispersed over short distances, but wind can carry some up to a quarter-mile from the parent tree.
Giant sequoia cones are serotinous, meaning the cones may remain attached to their stems without opening for up to 20 years. Three primary disturbance agents are responsible for opening cones: a longhorn beetle called the sequoia cone borer (Phymatodes nitidus), the Douglas squirrel (Tamiasciurus douglasii) and fire. Wind can also dislodge cones, causing them to open and dry out on the forest floor.
Giant sequoia seeds germinate best on bare mineral soil, and a thick duff layer can inhibit seedling growth or facilitate microbial activity that can cause mortality. Giant sequoias typically reproduce sexually via seed dispersal. But in rare instances, giant sequoia less than 20 years of age can reproduce asexually via vegetative sprouts, like redwood. More common — especially with young trees — low branches may “turn up” and can look like basal sprouting. Most natural regeneration occurs following fire.
Seedlings
Giant sequoia seedlings require high soil moisture within their first year of growth. Seeds released from cones just before the first snow in the fall or just as the snow melts in the spring are typically able to germinate sooner, produce roots earlier in the growing season and increase their chances of surviving the first dry summer.
Seedlings within established groves, where soil moisture conditions are generally better in spring, can attain a height of 8 to 12 inches after the second year.
Soils
Within native groves, giant sequoias grow in soils derived from granitic-based residual and alluvial soils, glacial outwash from granite, and other parent materials such as schistose, dioritic and andesitic rocks. They thrive in deep, well-drained sandy loams, which occur more frequently on mesic sites, such as drainage bottoms and meadow edges. Soil pH ranges from 5.5 to 7.5, with an average of about 6.5.
Fire regimes
Like redwood, the giant sequoia fire regime, including mean return interval, also depends upon associated plant communities. For example, giant sequoias associated with a large amount of white fir (with a comparatively longer fire-return interval) would have a much different fire regime than those associated with California black oak (with a shorter fire-return interval). Before fire exclusion was implemented due to national park status in 1864, the Mariposa Grove and Yosemite National Park sustained fires every 20 to 25 years; mid-elevation sites of the Sierra burned every five to 10 years.
The thick, furrowed, fibrous bark (Figure 12) of giant sequoia and its serotinous cones are fire-adapted traits. Additionally, repeated fires will reduce ladder fuels by killing lower branches, thereby making the tree even more fire-resilient.
Giant sequoias have prolific postfire regeneration, with as many as 40,400 seedlings per acre following heat-induced seed fall (Figure 13).
Forest health considerations
Redwood, giant sequoia and other trees in the Cupressaceae family are known for their insect- and disease-resistant wood. However, they are not immune to biotic and abiotic disturbances.
Redwood
Mature redwood experiencing stress can be attacked by two bark beetles: the cedar bark beetle (Phloeosinus sequoia) and cypress bark beetle (P. cristatus). Cedar bark beetles infest twigs, branches and the main stem (trunk) of trees weakened by drought, disease, fire and logging. They readily colonize broken branches and will also infest and kill saplings that are not suitable for a specific site. The insects attack stems, trunks, branches and tops. They are not aggressive pests, although they can kill trees weakened by drought or root disease.
Redwoods are occasionally colonized (infested) by a flathead twig borer beetle (Anthaxia aeneogaster) on the trunk, large branches and roots. The sequoia pitch moth (Vespamima sequoia) also infests the trunk and larger branches. Only in rare cases do these insects cause significant damage to mature or younger trees.
Several fungal agents are known to infect redwood at varying life stages of the tree. The Cercospora needle blight fungus (Passalora sequoiae) causes severe damage throughout the Cupressaceae family, especially in nursery stock. Symptoms of Cercospora needle blight usually begin in the lower part of the tree canopy and move from the plant's interior toward the branch tips. As infected needles age, they may turn from brown to gray.
Additionally, Ramorum leaf blight, caused by the invasive non-native funguslike organism Phytophthora ramorum, causes leaf spots, blotching and dieback of new branch tip tissue, especially on resprouts. (P. ramorum also causes sudden oak death, a fatal canker disease primarily on tanoak in Oregon.) Since Ramorum leaf blight is an invasive pathogen, it is essential to know where your redwood stock comes from (Figure 14).
Brown-cubical butt rot (Poria sequoia) is the most common rot in redwood and causes the most decay, particularly in old-growth on trees with basal scars or broken tops. Second growth is also susceptible, but the rot does not transfer from stumps to sprouts. White stringy rot (Poria albipellucida) is another rot in redwood stands, increasing in severity from the southern part of the range to the northern.
Annosum root rot, caused by the fungus Heterobasidion occidentale, has been observed in both redwood and giant sequoia stands. On redwood, it most commonly fruits on stumps, but it has also been seen in association with root failure of mature trees. In giant sequoia, it has been isolated from the root systems of dead trees. More study is needed of this pathogenic fungus in redwoods of both types.
Additionally, butt rot caused by the fungus Phaeolus schweinitzii has been observed in decaying redwood trees, particularly fire-damaged ones. Postfire, various decay fungi, especially decay sapwood (Coniophora puteana) lead to dramatic reductions in timber quality and, eventually, the formation of basal hollows commonly called “goose pens.”
Several other root pathogens, including Phytophthora cinnamomi, Elongisporangium spp., Pythium spp., Ilyonectria spp., and Fusarium oxysporum, have been observed in association with redwood decline and mortality.
The group of fungi known as the red belt fungus, or the Fomitopsis pinicola species group, is a minor pathogen of redwood, mostly decomposing downed woody debris and leaf litter. However, in some instances, the red belt fungus can cause a light brown cubical rot of the heartwood. A twig branch canker (Seiridium spp., including Seiridium unicorne) has been observed on sprouts and plantation trees of seedling and sapling size. This canker, which girdles stems and branches and causes branch dieback and flagging on mature trees, could become damaging in plantations.
Various other fungal pathogens, including those in the genera Diplodia, Diaporthe, Cytospora, Neofusicoccum and Fusarium, have also been isolated from branch dieback in redwood. Additionally, Botrytis cinerea (the cause of what is commonly called gray mold) is a common problem that leads to tip blight on nursery-grown redwoods and shaded saplings and sprouts in natural forests. It is most problematic in situations of high humidity and restricted airflow.
Like all tree species, redwood is subject to abiotic, or nonliving, stressors typically resulting from site conditions, weather and climate. Needle tip browning can result from a relatively cool spring followed by high temperatures (100°F).
Redwood is particularly intolerant of salt spray, unlike other conifers such as Sitka spruce (Picea sitchensis). Redwoods in the salt zone can experience severe branch tip dieback that is persistent and progressive, deforming the entire tree crown, particularly on the side exposed to the salt-laden wind. Distance to and within the salt spray zone should be a major consideration when planting redwood.
Wind can cause trees to uproot, especially if the soil is saturated by heavy rain or if pathogenic fungi have weakened the root system. Falling trees can, in turn, damage other trees, opening them up to infection and infestation by fungi, insects and other damaging agents.
Redwood’s thick, fibrous bark helps to protect it from fire. Still, young seedlings and saplings with thin bark are at risk.
California black bear (Ursus americanus) will strip the bark from conifers (a learned behavior) and eat the cambium. This usually leads to stem decay and eventual windthrow. See “Reforestation” for more information on black bear damage.
Giant sequoia
Fire is the most influential disturbance agent for giant sequoia. The tree has a complicated relationship with fire. While fire can kill seedlings and saplings that have yet to develop thick bark, fire is also crucial in preparing giant sequoia stands for regeneration by reducing competition for water, space and other resources such as light. It also exposes bare mineral soil for good germination (Figure 15).
Fire exclusion practices have increased competition pressure, the depth of the organic soil layer and the potential for larger fires that burn at high temperatures. These factors set the stage for lower giant sequoia regeneration and higher mortality.
Like redwood, giant sequoia is not immune to infection and infestation by insect pests and pathogens. However, these factors typically do not cause direct mortality beyond the seedling stage. The same disease may often have different degrees of intensity, depending on the tree's location.
As in redwoods, cedar bark beetles (Phloeosinus spp.) infest twigs, branches and the main stem (trunk) of trees weakened by drought, disease, fire and logging. They readily colonize broken branches and will also infest and kill saplings that are not suitable for a specific site, for example, when a seedling suitable for south coast Oregon is planted farther inland or north.
Botryosphaeria canker (Botryosphaeria dothidea) is common on giant sequoia planted outside of its range and is particularly damaging in warmer, lower-elevation sites. It may be triggered by heat damage to branch and bole tissues, so episodes of extreme heat may exacerbate its occurrence and severity.
Annosum root rot and shoestring root rot, caused by Armillaria mellea, are known root and butt rot pathogens. While these two root rots typically do not solely cause mortality in mature giant sequoia, they are linked to the degradation of root strength and stability over time.
Mortality in giant sequoia stands can be attributed to many abiotic factors, such as lack of resources (water, light, nutrients), increased stand density, fire, and some biotic agents, such as aggressive root diseases. Winter yellowing (chlorosis of needles) is a minor impact and will cause giant sequoia to turn bronze in color. Warm spring weather restores chlorophyll content, allowing the needles to green up.
Mature giant sequoias, which have shallow roots, lose their structural integrity over time to sustained years of insect and disease infestation and damage by fire. Eventually, strong wind topples the top-heavy trees, which remain on the forest floor long after death.
Other disturbance agents of giant sequoia include the Douglas squirrel. The squirrels feed on the cones, dispersing seeds and cones across greater distances. Unlike the problems with redwood, black bear damage has yet to be documented in giant sequoia groves. However, since removal of redwood bark is a learned trait, there is the potential for bears to target giant sequoia. See “Reforestation” for more information on animal damage.
Moving trees beyond their range
Habitat characteristics like hydrology, climate and soils dictate the types of plant communities found across the landscape. Each species tolerates a range of these site characteristics to increase their opportunities to grow across the landscape. However, if a species lives outside its range of tolerances, it becomes more susceptible to health issues and ultimately dies. As the climate changes, these habitat variables change over long periods, and species populations respond and adapt by slowly shifting geographically.
Recently, large shifts in average temperature and precipitation ranges have occurred more rapidly worldwide. These shifts affect plant communities, including increased mortality due to insects and disease. Oregon has experienced increasingly widespread die-offs across various tree species in response to unprecedented drought and heat.
When replacing these trees, it is important to choose trees that will live in both the current and future climatic conditions. As a response, many people are turning to redwood and giant sequoia as potential replacements or to add diversity to their properties.
Assisted migration (Figure 16) is the intentional planting of a tree species in a new place, outside of its normal range, with the aim of better matching future habitat conditions in a changing climate. When redwood is planted outside of the southern Oregon Coast and when giant sequoia is planted anywhere in Oregon, we are participating in assisted migration. Like all management decisions, assisted migration has both benefits and associated risks.
For some people, planting redwood and giant sequoia means restoring a diversity of live trees on their property after fire or other disturbance. People see potential income sources, opportunities to create resilient landscapes in a changing climate, carbon sequestration or an opportunity for increased diversity. Others simply enjoy these tall trees.
However, replacing or mixing our native forest trees with large areas of non-native species could create impacts of which we are not yet aware. For example, there is currently no research on how replacing and mixing Douglas-fir forests with redwood forests will impact our local insect and wildlife populations, hydrology cycles or other ecosystem services that have been responding to each other over the last few thousand years.
Additionally, it is unclear how purposefully shifting the tree communities will affect the genetic diversity of both the species being replaced and the species replacing it.
Whether or not you plant redwoods or giant sequoia, it is important to consider your goals. How will the benefits of planting non-native species help you reach them, and how will the risks deter you?
Reforestation and vegetation management
Redwood and giant sequoia differ in their tolerances to shade and temperature. Careful site selection, preparation and protection from animal damage are important for the success of both species.
Both redwood and giant sequoia have the potential for high growth rates when planted on suitable sites. Consider this differential growth rate when planting them alongside other species.
Additionally, redwood can be injured or killed by chemicals commonly used to remove competing vegetation and release other native conifers.
Before you plant redwood and giant sequoia, carefully consider your management objectives, regulatory considerations and site suitability. If you are interested in planting redwood, factor in the difficulty of removing this species, which sprouts prolifically.
There are many examples of these species growing outside their native range. Many redwoods and giant sequoias planted as landscape trees in Oregon before the 1900s can still be found today. A number of these early specimens likely survived by chance, having been planted in marginal or unsuitable sites during periods that were unusually moist or mild (without freezing or hot temperatures that would otherwise kill young seedlings). Landowners will have the best success on sites with climatic conditions similar to those of their native range.
Redwood nursery planting stock is established either through vegetative propagation techniques or from seed. Vegetative propagation techniques include taking cuttings from juvenile plant growth. Tissue culture techniques propagate redwoods from the cells of mature trees.
Landowners with redwood on their property may notice naturally occurring vegetative propagation (sprouting) from stumps (Figure 17) or roots (Figure 18). Any plant established using vegetative propagation techniques is referred to as a clone (Figure 19) because it shares the exact genetic makeup of its parent tree. Redwood planting stock established from seed may be less commonly available. Redwood seeds have low germination rates, making establishment from seed less reliable.
In contrast, giant sequoia nursery stock is predominantly produced through collection and germination of seed. Cultivated extensively since 1853, giant sequoia germination has been perfected in nursery settings. Nurseries produce the fastest-growing seedlings of the various propagation methods.
In the native range of giant sequoia, natural regeneration is largely unsuccessful unless careful conditions are met. The site must have been disturbed by a fire that was followed by a moist spring; it must also have neighboring trees over 150 years old. Trees must reach that age to produce viable seed for reproduction.
Vegetative propagation of giant sequoia is possible. Trees under 20 years old can successfully root from cuttings. Injured trees sometimes sprout from stumps. In a recent study in California, seedling stock grew faster than clones collected from the same groves. Researchers also found that seedlings had less epicormic sprouting (sprouts coming from the tree stem) than clones — an advantage if you are harvesting them for wood products.
Redwood and giant sequoia seedlings or clones are typically available for purchase from a number of forest seedling nurseries in Oregon (see “Resources”). Nurseries will generally provide the geographic area (seed zone and elevation band) where the seed or vegetative material was collected.
Oregon has no established seed zones for redwood and giant sequoia, and there is considerable uncertainty on which California seed zones would grow best in Oregon. Try to choose planting stock from areas with similar climatic characteristics. For example, when selecting redwood planting stock for the Oregon Coast, consider stock from the northern California coast, which would share more similarities than sites farther south. Likewise, sources from farther south may be better suited for warmer sites, and sources from higher elevations may be a better choice for Oregon sites inland from the coast. The nurseries growing these trees usually participate in trials and will have resources to help you determine the best option for your area.
Another consideration is stock size. Currently, most of the Oregon stock for these species is container-grown, referred to as plugs. Plugs and small planting stock sizes may be more susceptible to animal damage and generally have better success in areas with good site preparation. Keep this in mind when planning your site planting. Larger planting stock may be advantageous, provided the site has adequate moisture. For information on the various seedling sizes, see Selecting and buying quality tree seedlings, EC 1196.
Either species will thrive best in areas that closely approximate the conditions in its native range. For redwood, this includes moist sites and flat areas with deep soils. Seedlings require adequate soil moisture due to a lack of moisture-extracting root hairs. Avoid planting redwood seedlings, particularly young seedlings, in frost pockets.
Additionally, riparian sites and sites susceptible to flooding may be appropriate as long as the soil does not remain saturated for extended periods. Sites in the fog belt may also yield success, keeping the previous limitations in mind. Redwood is shade tolerant and thus suitable for understory plantings where the objective is to create a layered stand structure.
Giant sequoia requires plenty of ground moisture and grows best in deep, well-drained sandy loam soils with full sun. They can handle freezing temperatures to about negative 12°F (negative 24°C), but extended hot temperatures could impact the health of this species. Sites with shallow or rocky soils may also be an option if ample underground water is available. Riparian corridors, drainages, meadow edges or steep slopes are other options for planting, as long as they aren’t underwater for extended periods.
Neither species thrives in sites with high water tables or arid areas. If planting on drier sites, consider mulching to conserve soil moisture. Likewise, frost pockets or areas with cold, windy salt spray will yield poor success. Other areas to watch out for include areas with compacted soil or heavy grass competition.
For both species, adequate site preparation is important and includes creating planting areas that reduce grass and shrub competition with seedlings. See Enhancing reforestation success in the Inland Northwest, PNW 520, for information on vegetation management techniques.
In studies performed in its native range in California, the total height and foliage retention of giant sequoia were only slightly lowered when grown in untreated brushy areas with heavy shrub competition. However, when planting in Oregon, ensure the site is free of excessive slash (logging debris) and competing grass, shrubs and forbs to reduce potential mortality. Leave some pieces of down wood (12 inches or greater in diameter) to shade seedlings. This may improve survival on hot, south-facing slopes.
For redwood, initial planting densities will depend on your management objectives. Planting at a tighter spacing (10–12 feet) can rapidly exclude competing vegetation but will require thinning later to maintain stand health. Planting at lower densities (15–20 feet) will favor individual tree growth and full crowns, allowing more light to enter the understory. Seedling mortality may create larger openings than anticipated when planting at lower densities.
Similarly, giant sequoia can grow well in pure stands, but your planting should reflect your personal management objectives. If you want to maximize wood production, you can plant trees at a tighter spacing (10–15 feet). However, due to their high growth rates, they will require an early (at approximately 4 years) precommercial thinning with a minimum of 16 feet spacing. This will also help to reduce competing vegetation and tree taper (though some trees may still need pruning). Alternatively, planting at a wider spacing (16–20 feet) also maximizes wood production because these trees grow quickly. However, you’ll need to prune to reduce tree taper and excessive branching at the tree's base. High taper and numerous knots result in less value at the mill.
Wider spacing may be the easier choice for small landowners because of the lower initial investment. Additionally, wider spacing produced trees with larger diameters even without pruning. The larger trees were more merchantable at the mill, even though total stand volume was virtually the same as trees planted more densely. This spacing would also benefit those not interested in planting specifically for timber objectives.
Landowners adding redwood into mixed-species plantings should consider the differential growth rate of various species. Redwood may reach a merchantable size years before other species, such as Douglas-fir. Additionally, redwood can survive and grow at much higher densities than any other conifer. If you are selectively harvesting redwood from mixed-species stands, think about how to protect retained trees from logging damage. Planting redwoods in patches and harvesting as a unit may be effective for landowners anticipating earlier harvest of redwood from a mixed-species stand.
Another option is to plant redwoods in the understory of established stands to develop a layered stand structure. If you protect the understory during harvesting operations, redwoods will grow slowly in the shade of other conifers and release after the overstory harvest.
In their native range, giant sequoia is typically only found in pure clumps within mixed stands. For this reason, it’s a good candidate for mixed-species plantings. Giant sequoia can be planted with one or more other species in even mixtures at planting densities from 10 to 20 feet. Due to their shade intolerance, plant giant sequoia in a clump in the center of the gap or opening with the other species on the edges (Figure 20). You can also plant them dispersed among the other species, but consider their high growth rates (commonly 24 inches in one year) when choosing the other species (Figure 21). Giant sequoia is unique among species in its ability to sustain height growth when planted in low densities.
Redwoods and giant sequoia are susceptible to animal damage. Deer damage young saplings by rubbing their antlers against tree trunks and stripping the bark. Bears cause severe damage by clawing through the bark to feed on the cambium. Bear damage (Figure 22) is a serious concern in areas of Southern Oregon, where some landowners avoid planting redwood altogether. Woodrats (also called pack rats; Neotoma spp.) can strip bark extensively on saplings and older trees (Figure 23). In some areas, woodrat nests are extensive (Figure 24). Gray squirrels are also known to strip redwood bark and girdle the tops of giant sequoia trees (Figure 25). Additionally, rodents in grassy areas can damage and kill seedlings. Voles will peel the bark of giant sequoia seedlings and saplings up of to 8 inches basal diameter.
There are several approaches to preventing damage from animal browsing. These include rigid mesh tubes (installed with a stake), flexible mesh bud caps (positioned over the terminal bud), applying animal repellent, or wrapping metal foil around the base of seedlings, which has been shown to deter vole damage. While these approaches may work for small trees, they will not provide long-term protection. Seedlings will quickly outgrow plastic mesh tubes, and animal repellent will require reapplication.
Controlling competing vegetation — referred to as conifer release — may be necessary to ensure that these two species are free to grow. Successful release methods include manual or chemical approaches. See Introduction to conifer release, EC 1388, to learn about release methods and how to determine if release is necessary. Giant sequoia responds well to release from competition even after many years of suppression.
Some chemicals often used to release other conifers can severely injure or kill redwoods. For example, Hexazinone and 2,4-D ester can damage redwood if applied at an incorrect rate.
Another method for controlling competing vegetation is the use of mats (often referred to as “weed” or “mulch” mats). Mats come in various sizes and materials, including landscaping fabric or biodegradable products such as paper that deteriorate within one or two years.
Mats should be 3–4 feet in diameter to provide adequate vegetation control. Weigh them down with rocks, woody debris or soil to prevent them from blowing off or blowing over and smothering the seedling. Mats are expensive and time-consuming to lay out around seedlings, but they are an effective nonherbicide alternative to controlling vegetation.
Follow-up after planting
After seedlings have been planted, follow-up inspections are critical to success. Inspect plantings at the end of the first year to see if there is abnormal mortality (and determine what’s causing it, if possible). Examples of abnormal mortality include sizable gaps in the planted area or scattered mortality that reduces seedling stocking below what you would prefer or what is required by regulation. Look for vigorous vegetation regrowth or obvious damage from animals. If you used planting tubes (either rigid or flexible), check to ensure that they are still installed properly. It is easier to fix problems early on than to wait several years before finding substantial seedling mortality.
Silviculture and forest management
Redwood and giant sequoia can grow rapidly if they are planted in appropriate sites. Landowners can choose among several harvest-regeneration approaches to meet individual management objectives (Figure 26). Note that most available information regarding optimum planting densities and management strategies for these species is based on studies undertaken in California and, more recently, New Zealand.
Even-aged management
Both redwood and giant sequoia will grow rapidly in pure stands in full sunlight, making them suited for an even-aged silvicultural system (Figure 27). However, even-age stand structures are not common in naturally occurring stands in their native range due to the variable patterns of natural disturbance. If planting for economic objectives, the capacity of mills to take large logs may limit rotation length (age of stand at harvest).
Clearcutting
Clearcutting is an even-aged management strategy that involves cutting and harvesting nearly all the trees in a forest stand. You may be required to leave some trees for wildlife habitat under Oregon’s forest practices requirements for clearcuts over 25 acres in size.
Following harvest of a redwood stand, the area regenerates from stump sprouts. (Managing the resulting sprouts to produce mature trees is called “coppicing”). If there are areas within the clearcut with few redwood present before harvest, planting redwood seedlings or other tree species may be appropriate, depending on your objectives. Planted redwood stands have been harvested in Oregon at the age of 40.
Giant sequoia has not been a preferred species for lumber, so there has been limited commercial harvesting of the species. Thus, there is little experience managing giant sequoia in an even-aged fashion using clearcutting. Landowners interested in growing this species for a potential log market or carbon sequestration can consider taking advantage of the rapid growth, both in height and diameter, when planted at low densities. Planting at wide spacings combined with early pruning to reduce taper could result in a sawtimber-sized tree at a young age. Otherwise, planting at tighter spacings can help reduce taper but will likely require thinning for optimum growth. See examples of thinning strategies in “Intermediate stand treatments.”
Seedtree and shelterwood cutting
Seedtree and shelterwood cutting are even-aged management strategies that involve reserving one to nine trees for a seedtree cut or 10 or more for a shelterwood cut. Typically, the best best-formed dominant and codominant trees are reserved as seed and shelter trees. The original purpose of seedtree and shelterwood cutting was to reserve high-quality trees to provide natural seeding to regenerate the understory and initiate a new stand. Shelterwood also provides protection or “shelter” and thermoregulation on less suitable sites, which aids in successful seedling establishment. Five to 10 years later, the seed or shelter trees are removed to release the understory.
However, since redwood regeneration arises from resprouts from cut stumps and giant sequoia seeds are not viable until about 150 years old, the seed and shelter trees are not needed for regeneration purposes. But landowners may be interested in this method for aesthetics, habitat, wind protection or other reasons. Retaining seeds or shelter trees indefinitely creates a stand with two distinct age classes.
Two-aged management
Creating two-aged stands and forests can enhance forest structure, wildlife habitat, aesthetics, carbon sequestration and more while providing wood products and revenue.
Creating a forest with two distinct age classes begins in much the same way as a heavy seedtree or light shelterwood cut. Most trees are harvested in this case, leaving five to 10 large trees per acre. However, the overstory trees remain standing and will not be harvested in future entries.
Following harvest of a redwood stand, the redwood stump sprouts create an even-aged stand (cohort) that develops beneath the light overstory of large trees. As the understory trees grow and develop, they can be managed with precommercial thinning at the appropriate age and residual density, if needed. Follow with commercial thinning when the understory trees have reached commercial size. One or more commercial thinnings may occur, depending on the understory cohort’s rotation age or final harvest. If any large overstory trees have died in the interim, trees from the understory cohort can be allocated to replace dead or dying trees to maintain the upper canopy.
Landowners interested in developing a multilayered stand can take advantage of redwood’s shade tolerance by planting in the understory of established conifers. Growth in shaded environments will be substantially reduced. In New Zealand, redwood is sometimes planted under Italian alder. This forces the redwood to grow upward. An added benefit is the nitrogen-fixing properties of alder. The redwoods eventually overtop the alders, and the alder eventually declines.
There is little information on actively managing giant sequoia using this two-aged management strategy.
Multi-aged management
Multi-aged management creates stands with three or more age classes (cohorts) on the same acre or area of interest and therefore have a more complex structure. Periodic harvesting entries create growing space for a new age class of trees and to provide periodic revenue. There are two methods for creating multi-aged forests: group selection and single-tree selection.
Group selection
In the group selection method, small areas or patches (typically with a harvest radius twice the height of mature trees) are harvested over time to create multi-aged cohorts. In a redwood stand, the stumps from harvested redwoods will sprout and form new age-class groups. In stands composed of other species, redwood can be planted in small patch cuts to create a complex multi-aged stand.
Giant sequoia is shade intolerant and will perform better in the center of group selection areas larger than 1.5 to 3.0 acres. Overall, group openings 1–3 acres in size should accommodate both species.
Timing of harvest entries (to create another age class) depends on the age you are managing to. For example, if you manage redwood on a 60-year rotation, cutting a third of the stand (composed of small groups) every 20 years will create the desired three age classes to a maximum of 60 years.
Note that this system requires periodic entries and careful designation of skid trail and landing locations. You can reuse these in subsequent entries, reducing damage to recently established trees (in the group openings) and limiting soil compaction across sites.
Single-tree selection
In the single-tree selection method, individual trees are harvested in all size classes within a stand up to a designated maximum diameter at breast height (approximately 30 inches DBH). In a redwood stand, single-tree selection results in stump sprouts that will grow in the small openings (Figures 28, 29). In stands of other species, redwood can be planted in small gaps created by single-tree selection. Sprouts or planted redwood will not thrive in low light conditions.
Giant sequoia is shade intolerant and will not thrive in a single-tree selection method.
As noted above, designated skid trails and landings will limit tree damage and soil compaction.
Riparian planting
Redwoods have been planted to restore conifer cover in riparian areas along some streams. Redwood is well suited for this, as it can tolerate some shade and will eventually develop a canopy to provide shade. It will also produce large wood that eventually will fall into the water to enhance stream habitat. Many riparian plantings can be negatively impacted by beaver feeding and cutting, but redwoods can resprout, survive and continue growing (Figure 30). The Coos Watershed Association in Coos County planted redwood along riparian areas.
Intermediate stand treatments
Intermediate stand treatments aim to enhance tree or stand characteristics. These include precommercial thinning, commercial thinning, improvement cutting and pruning.
Precommercial thinning
Assess redwood stand density at 10–20 years of age to determine whether a precommercial thinning is needed to maintain stand health and individual tree growth. Redwood grows at high densities compared to other conifers (Figure 31). However, PCT can profoundly affect tree diameter in later years, affecting stand volume, merchantability and value. For example, a California study compared precommercially thinned redwood and Douglas-fir stands at age 19 with six different spacings (Figure 32). At age 49, average stand diameter incrementally increased as PCT spacing increased. At the widest PCT spacing (100 trees per acre), the average stand diameter was 24 inches at age 49. In comparison, precommercial thinning of Douglas-fir showed a modest effect on average stand diameter at the same PCT spacings.
PCT spacing will depend on landowner objectives. A 14-foot spacing would suit primarily economic objectives with a relatively short rotation. That spacing would also be appropriate in the case of a planned commercial thinning. Wider spacings (16- to 20-foot) would favor individual tree growth and diversity of other species, and moderate thinning (150–250 TPA retention) can balance individual tree growth and flexibility for future management options. Old-growth redwood stands in their native range have low densities (less than 50 TPA). If old-growth characteristics are desired, multiple thinning entries would be required over many decades.
Variable-density thinning approaches (thinning at different densities within a stand) can achieve diverse species composition and spatial heterogeneity. Precommercial thinning may encourage sprout reproduction from cut redwood stumps. Leave trees may be more susceptible to bear damage, resulting in reduced densities.
For giant sequoia, an early precommercial thinning to a minimum of 16 feet and commercially thinning to 21-foot spacing will promote growth.
Some landowners may be managing their second rotation of planted redwood in Oregon. Sprouts grow from stumps and roots after redwood is harvested, and sprouts typically undergo precommercial thinning at age 10 to 20 years. Select two to three sprouts per clump for retention, considering root sprouts are more vigorous. Avoid sprouts on stumps, because once the stump rots, the developing sprouts become weakened and can break off. Depending on your objectives, you can thin sprouts at spatial patterns ranging from evenly spaced to a more random pattern, as found in natural stands.
Commercial thinning
If redwood stands are managed beyond 35–40 years, landowners may want to consider commercial thinning to maintain stand growth and forest health, enhance value, or promote ecological values. Redwood stands may be commercially thinned starting around age 30–35, depending on several factors: initial density; whether PCT was conducted earlier; site productivity; local mill log requirements and prices; and logging and hauling costs.
Thinning can be carried out in a uniform manner or by using a variable density approach. Variable density thinning (thinning at different densities within a stand) can achieve diverse species composition and spatial heterogeneity.
Old-growth redwood stands in their native range have low densities (less than 50 trees per acre). If old-growth characteristics (very large diameters) are desired, multiple thinning entries over many decades would be required.
Table 1 displays stand densities where there is good site utilization and that minimize mortality from tree competition. For example, if a stand has an average diameter of 12 inches, you could have between 284 and 448 trees per acre.
If you have more than 448 trees per acre, thin trees to prevent mortality from excessive competition as the trees grow. Depending on your objectives and other stand conditions, thin down to 284 trees per acre or somewhere in the middle of that range. Thinning should remove weaker suppressed, intermediate and some codominant crown classes. Leave the more vigorous codominant and dominant trees. This is often called a “low thinning” or “thinning from below.” Depending on site and soil conditions, appropriate densities for redwood planted in Oregon may be slightly lower for each average stand diameter in Table 1. These are preliminary thinning guidelines.
|
Average diameter at breast height |
Trees per acre at low density |
Trees per acre at high density |
|---|---|---|
| 10 | 381 | 600 |
| 12 | 284 | 448 |
| 14 | 222 | 350 |
| 16 | 180 | 283 |
| 18 | 149 | 234 |
| 20 | 125 | 198 |
| 22 | 108 | 170 |
| 24 | 94 | 148 |
| 26 | 82 | 130 |
| 28 | 73 | 115 |
| 30 | 65 | 103 |
Note: This table is based on a maximum Stand Density Index of 1090. Low density = 35% of max SDI and high density = 55% of max SDI. See Measuring your trees, EM 9058, for information on taking plot measurements to determine trees per acre.
Redwood is a popular timber species in New Zealand, where it is planted with a rotation length of 35 years with a target diameter of 24 inches. Initial spacing is approximately 340 TPA. Stands are precommercially thinned to 141 TPA. Plantings at wider spacings (253 TPA) may not require precommercial thinning.
Little is known about commercial thinning in giant sequoia. A thinning study in California demonstrated the rapid growth of giant sequoia compared to other species, although the species has not been in high demand for lumber. Giant sequoia has not been thinned for commercial purposes, but rather to reduce fuels and maintain health and vigor.
A cut stump (Figure 33) shows rapid early growth and then a reduction in growth due to competition.
Improvement cutting
Improvement cutting is a management strategy that removes undesirable tree species, trees with poor form and damaged trees. Some damaged trees that will likely die can be left for wildlife habitat.
Pruning
Pruning redwood and giant sequoia can help create clear boles (wood without knots). Pruning giant sequoia can help reduce stem taper, which is more pronounced when giant sequoia are planted or managed at wider spacings. Weigh possible future economic returns against the cost of pruning. For many landowners, pruning may be desirable for aesthetics and fuel reduction (to reduce ladder fuels).
In both species, pruning may result in undesirable epicormic branching (growth of new shoots on the stem in response to pruning cuts, stress or increased light). In redwood, epicormic branching can be reduced by leaving at least 40% live crown and choosing a stand spacing so that pruned trees are not exposed to excessive light or heat after thinning. In giant sequoia, leave more than 60% of the live crown.
Growth and yield
There is limited information on redwood growth and yield in Oregon. However, some impressive examples exist where pure redwood stands were planted decades ago and recently harvested. Figure 34 shows a few case examples from redwood stands planted with coast redwood in the fog belt of Central and Southern Oregon.
Giant sequoia expresses impressive growth within its natural range. Even in Oregon, volume growth is excellent under varying site conditions, from moist to moderately dry sites. While growth and yield estimates are limited, Table 2 shows naturally regenerated giant sequoia stands following clearcut harvests with little stand management.
|
Stand age (years) |
Total volume |
Ingrowth |
Mortality |
Periodic annual increment |
Mean annual increment |
|---|---|---|---|---|---|
| 7 | 0 | 0 | 0 | 0 | 0 |
| 13 | 0 | 0 | 0 | 0 | 0 |
| 18 | 188 | 188 | 0 | 38 | 10 |
| 22 | 743 | 291 | 0 | 139 | 34 |
| 31 | 5,938 | 2,966 | 0 | 577 | 192 |
| 63 | 24,237 | 0 | 0 | 572 | 385 |
| 73 | 35,801 | 641 | 0 | 1,156 | 490 |
| 77 | 40,320 | 69 | 22 | 1,130 | 524 |
| 83 | 49,714 | 295 | 24 | 1,566 | 599 |
| 86 | 54,077 | 204 | 0 | 1,454 | 629 |
Revised from Dulitz, D. 1988. Forest statistics. Mountain Home Demonstration State Forest.
In another example from California, giant sequoia was planted at several different initial spacings on the northern edge of its range. Table 3 shows diameter and cubic foot volume growth after 28 years. In general, tree size (DBH) and volume increase as density decreases over the 28 years, although at the 20-foot spacing volume is slightly below the 18-foot spacing. Trees at wider spacings may display a lot of stem taper and may benefit from pruning to improve stem form. Volume growth at the broader spacings (12+ feet) is impressive.
Information on volume growth of giant sequoia in Oregon is currently scant. There have been some plantings on the eastern flank of the Coast Range and in forested areas around the Willamette Valley.
|
Initial spacing (ft) |
Trees per acre |
Diameter at breast height (in) |
Volume/acre (ft3) |
|---|---|---|---|
| 6 | 1,094 | 7 | 0.0 |
| 7 | 842 | - | 497.2 |
| 8 | 670 | - | 436.1 |
| 9 | 545 | 9 | 1517.7 |
| 12 | 363 | - | 4937.1 |
| 14 | 274 | 12 | 4466.0 |
| 16 | 214 | - | 6969.5 |
| 18 | 171 | 15 | 8731.4 |
| 20 | 143 | 16 | 8591.9 |
Interpolated from Figure 5 in: Cox, L.E., York, R.A., and Battles, J.J. 2021. Growth and form of giant sequoia (Sequoiadendron giganteum) in a plantation spacing trial after 28 years. Forest Ecology and Management, 488, 119033.
Wood quality
Wood properties
Coast redwood and giant sequoia have key similarities and differences in wood quality and products. The wood properties of these species are comparable. Both are lightweight but strong and soft, with a coarse texture. Both species are also considered resistant to decay from various insects and pathogens, but coast redwood is more resistant than giant sequoia.
The species differ in that coast redwood’s wood properties become more favorable as an old-growth tree. Giant sequoia is both stronger and heavier as a young-growth tree.
Redwood’s heartwood is reddish-brown, but giant sequoia’s heartwood has purple undertones.
Giant sequoia also has numerous branches, which can lower the quality of wood products. With proper early pruning, the wood value reaches full potential.
Markets
Currently, there is no market for giant sequoia in Oregon. Redwood is only commercially sold on the south coast of Oregon, but it is mainly milled in California. Most cedar mills are willing to consider running redwood, but currently there isn’t enough stock available to fill a full operational shift. Otherwise, local portable millers, firewood distributors or artisans will purchase logs for their needs.
Wood products
Redwood is used for high-value building construction, heavy beams, bridge timbers, planks, siding, sash, doors, veneer, furniture, cooling equipment, plywood, pulping, particleboard, shakes, shingles, grape stakes, paper, poles and posts. Its decay resistance makes it a preferred choice for exterior siding, outdoor decks, hot tubs and garden features. Additionally, the fibrous bark is used for hog fuel, insulation and garden mulch.
Redwood is also prized for its burls, a growth on a tree that causes the grain to become disfigured. The disfigured grain creates intricate patterns when used for figured tabletops, veneers, bowls and other turned products. Burls can be found on the stem or base of the tree. They vary in size from 1 inch to multiple feet in diameter. Live burls with dormant buds can also be kept as houseplants. Don’t remove burls from live trees, because this would expose the tree to potential insect, disease or other stressors that may affect the tree’s long-term health.
Old-growth giant sequoia was historically used for fenceposts, grape stakes, shingles, novelties, patio furniture and pencils. Young giant sequoia, which has more favorable wood properties, can also be used as dimensional lumber, veneer, plywood and pulp.
Coast redwood is highly valued and is often the most expensive wood product on the market. However, it is reasonable to consider giant sequoia as an additional option due to its comparable wood quality and superior volume growth in managed stands. The high-quality wood properties are present in young stands, which means old-growth groves can remain protected.
Regulatory considerations
Redwood is native to the south coast of Oregon and is considered a non-native species for the rest of the state. Giant sequoia is not regarded as native to any part of Oregon. Regulatory agencies and county assessor’s offices may have rules that impact or even prohibit a landowner’s ability to plant non-native redwoods for reforestation or in habitat restoration projects. It is essential that landowners properly plan for and understand regulatory aspects before planting these species.
If you would like to plant redwoods after a timber harvest, check with your Oregon Department of Forestry stewardship forester to ensure redwoods are considered a suitable native species to fulfill reforestation requirements in your area. In some instances, you may need an alternate plan of practice. In any case, if redwoods are not successful on the site, you may have to replant, resulting in additional costs.
Suppose you want to plant an enrolled property with a majority of non-native species. In that case, the property may no longer qualify for the forestland special assessment program unless the Oregon Department of Forestry approves a written stocking plan for alternative practice. You may be liable to meet certain financial obligations to exit the program. Contact your county assessor's office to learn more about the Forestland Program.
The USDA Natural Resources Conservation Service administers many cost-share and competitive grant programs for landowners nationwide. These programs, such as the Environmental Quality Incentives Program, enable landowners to integrate conservation practices into working lands. While each program has different eligibility and implementation requirements, native species for the area are generally considered acceptable for planting or reforestation efforts. You will want to talk with your local NRCS office before finalizing which tree species to include in planting efforts under these programs. Cost-share programs likely exclude both redwood species for reimbursement in all areas of the state, with the exception of redwood on the southern coast.
Don’t plant redwoods next to a home, septic system or neighboring property. Their roots invade pipes and gardens and can break sidewalks and road surfaces. Redwoods can grow at a rate of 3–10 feet in height per year. Consider their size before planting. Additionally, urban areas may prohibit trees that block viewscapes, or regulate their proximity to roads, sidewalks or powerlines. Check if your city has a tree ordinance before planting trees in urban areas. Many other species are more suitable to urban settings. See Selecting, planting, and caring for a new tree, EC 1438, for a selection of tree species for various site conditions.
In Oregon, landowners can enroll in special programs that reduce the annual property tax on forested properties. These programs, offered through the Oregon Department of Revenue via the county assessor, provide annual tax savings for property owners. These programs only apply to forested properties that are adequately stocked with marketable tree species as determined by Oregon Department of Forestry stocking standards in OAR 629-610-0050.
Summary
Whether you have already planted redwood and giant sequoia or are considering one or both species on your property, the information and resources provided here will help you make decisions and plan management.
As is the case for any tree species you are considering planting, be sure to:
- Carefully evaluate, plan and prepare your site. Let’s say you recently visited California and fell in love with giant sequoia. You want to plant them on your woodland, but your site currently has a lot of red alder (Alnus rubra), and there is standing water for several weeks during the spring. Even after good site preparation, neither giant sequoias nor redwoods can tolerate their roots being wet for long periods. They can become weakened and susceptible to harmful pathogens, and eventually may die.
- Select the proper species and seedling/clone stock type for your site. All tree species require resources to grow — light, water and nutrients — even more shade-tolerant species, like redwoods. If you are planting in the understory or in an area that doesn’t get a lot of sun, giant sequoia will not do well, regardless of stocking type.
Remember, planting any tree species outside its native range presents both opportunities and challenges. Assisted migration of redwood and giant sequoia can help achieve long-term species conservation goals, but redwood is also a prolific resprouter and could be considered invasive.
In Oregon, redwood is likely most appropriate in the coast region. At the same time, giant sequoia could find a home in moist, cool settings at mid-elevations in the west Cascades and perhaps around the periphery of the Willamette Valley.
Resources
Jensen, E.C. 2021. Trees to know in Oregon and Washington, EC 1450. Oregon State University Extension Service.
Olson Jr., D.F., D.F. Roy and G.A. Walters. 1990. Redwood.Silvics of North America.
Save the Redwoods League. (2025).
Weatherspoon, C.P. 1990. Giant sequoia. Silvics of North America.
About the authors
