View this gallery of images and plant profiles of some WaterWise plants.
WaterWise
California Lilac (Ceanothus sp.)
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Consider new Ceanothus varieties for tough, dry locations
Ceanothus is a genus of native North American shrubs with about 60 species. The name Ceanothus comes from the Greek name keanothos, spiny plant. The shrubs are commonly thought of as California native, hence the common name on the west coast of ‘California lilac’.
About 36 of the species are found only in California, but there are several Ceanothus species that range over the western, mid-western and eastern United States and southern Canada. C. americanus is native to a wide area of the east and is known as ‘New Jersey Tea’.
Virtually all the western species are found in very dry habitats. Ceanothus inhabit scrub and woodland on exposed, dry slopes from mountains to coastal regions. Ceanothus can grow on poor soils as they have nitrogen fixing bacteria that form nodules on the roots. As a result, the characteristic that the species of Ceanothus share, and for which they are often known, is tolerance of poor, dry soil. It is in these sorts of situations that the plants are best utilized.
The most commonly grown Ceanothus in the Pacific Northwest are ‘Victoria’ and C. gloriosus.
These two are very different in habit -- the former being a rounded shrub to 8’ tall, the latter having a low, widely spreading habit and so is used principally as a groundcover. Both are hardy and attractive varieties.
Yet these two only offer a fraction of the range of size, habit, color and texture that the genus has to offer. There are plenty of other, less-commonly grown cultivars that are well-adapted to our region and worth growing:
- Ceanothus cuneatus var. rigidus ‘Snowball’ grows to 3’ tall and 6’ wide, with gray foliage and white flowers in April, and makes a great groundcover.
- A larger growing plant, ‘Wheeler Canyon’, has a mounding form to 4’ tall and 8’ wide with blue flowers and would be excellent as a large-scale evergreen groundcover.
- ‘Blue Jeans’ is a smaller evergreen plant to 4’ by 4’ with small, tough medium green leaves. It is one of the earliest Ceanothus to bloom, usually in April.
Cascara
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Cascara is many things to many people.
To some, it is a graceful understory tree. To others, cascara is a time-honored mild laxative. In recent year, it has become a recommended street tree because of its smaller size and beautiful leaves. And now, it has joined the list of WaterWise plants for home landscapes. I have two small cascara in my garden and both are doing very well with minimal care.
Although the OSU Plant Identification website lists this as growing to 50 feet tall, this will not typically occur in landscape situations where it tends to maintain a shorter stature. Cascara can grow either in a tree or shrub form, but I think the small tree form is more adaptable for most gardens. It does well in sun or shade. Although it is drought tolerant and does well in native forests, providing some irrigation does improve its appearance in the dry summer months.
In nature, cascara occurs from British Columbia to northern California, with limited distribution east of the Cascades. In Oregon, these tend to be in the Blue Mountain area or in the higher Cascades East of the crest. The leaves are up to 3-4 inches long and prominently veined with golden fall color. In late summer, small flowers are replaced by small purple- black fruit, which remind me of cherries. For more information and pictures, visit the OSU site listed above. To explore its medicinal and other attributes, visit Wikipedia.
Common Juniper (Juniperus communis)
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Want a native groundcover that is drought tolerant? Want it to be evergreen and minimum care?
Would you also prefer one that has some cultivars for a broader selection? The common juniper (Juniperus communis) is a plant to consider. The image shown here is a prostrate form of common juniper growing in the wild, only one of many photographs available at the OSU Plant ID site. Even the semi-upright and upright forms are still dwarfed and have a lot of gardening potential.
Virtues you may be interested in include:
- The ability to grow in poor soil
- Adaptable to a wide range of conditions
- Hardy at cold temperatures (Zone 2)
- Dozens of available cultivars. For example, you can choose from ‘Alpine Carpet’ a prostrate form with bluish scales, or ‘Depressa aurea’ with yellow foliage that grows to about 5 feet.
Although native to the Pacific Northwest, this species can also be found in northern climates throughout the globe, leading to the wide array of cultivars and conditions this species offers. Most of the Pacific Northwest forms are prostrate in habit. Our native form is J. communis var. depressus.
It does have other uses as well. According to a food information site at Oregon State University berries are used to:
- flavor gin,
- as a pepper substitute,
- to brew a special French beer, and
- as flavoring in sauerkraut.
To find the native form, check with local or regional native plant nurseries. The cultivars can often be found at larger garden centers.
Coreopsis
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One large category of plants for WaterWise Gardens grow in U.S. prairie habitats
This is primarily in the Midwest or the Southeast; some also grow in similar habitats in other parts of the world. Familiar garden plants from prairie habitats include: coneflower (Echinacea), blanketflower (Gaillardia), Rudbeckia, and sunflowers (Helianthus)—all are good candidates for water efficient landscapes. These species are also members of the sunflower family, called Asteraceae.
Another member of this group is Coreopsis, known commonly as tickseed. Perhaps not the most inspiring of common names, this nickname for the genus refers to the shape of the seeds, which must have reminded someone of ticks. Most members of this genus have yellow flowers, others are gold or pink, but plant and leaf form vary considerably.
Several are commonly featured as garden perennials, including Coreopsis verticillata ‘Moonbeam’ and C. grandiflora ‘Sunray.” These are among the approximately 35 different known species, of which most are native to the US. The genus is the state flower of Florida.
Let’s taker a closer look at one of the species-- Coreopsis verticillata (whorled tickseed, threadleaf tickseed).
- It is native to the eastern part of the US all the way from Pennsylvania and New York to Florida and west to Arkansas.
- In nature it grows at wood edges and in Pine savannahs; both open habitats are similar to many garden settings.
- It has been grown in gardens for more than 100 years, and helps support wildlife through nectar and food sources for birds and insects.
- It grows relatively easy from seed, and established clumps can be divided to produce additional plants.
Cosmos
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Cosmos
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Cosmos seems to grow readily in most gardens in our area.
I found myself wondering the other day where it comes from—any guesses before you read further? It certainly is a popular annual in our Willamette Valley climate. It grows well, self-seeds in favorable environments, and seems to be right at home, even with minimal irrigation.
One reason is that Cosmos is successful and drought tolerant or WaterWise is that it is native to nearby Mexico. Despite its southern origin, it grows as an annual in nearly all USDA zones within the US. Many cultivars have been developed and are available, in addition to the ones closer to the wild species.
Several Cosmos species are in the plant trade; the genus is a member of the sunflower family (Asteraceae). Cosmos sulphureus is yellow or orange. The more familiar Cosmos bipinnatus is pink, lavender, maroon, or white.
Both species can grow up to 6 ft in a garden setting! Plant young plants or seeds in sunny locations where taller plants are welcome.
Provide some irrigation (preferably by a drip system or another way to avoid overhead irrigation) during long dry periods, and water thoroughly and deeply. Shallow watering encourages shallower roots which will make your plants less drought hardy.
In windy or open areas, the plants may need staking, but you can do without this in mixed beds because the other plants will help hold them up.
Cosmos make good cut flowers as well. So enjoy this perky annual plant and save water at the same time.
Crocus
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Winter inevitably makes me think of spring, or at least the promise of spring, including Crocus.
This is one of the first plants to bloom each year, and like most bulbs or bulb-like plants, is also WaterWise, thriving with little or no additional water to come back year after year.
Although there are about 80 species in the genus, the most popular are the Dutch crocus, cultivars of Crocus vernus. Crocus are members of the iris family (Did you guess Iridaceae before you read this?), are native to summer dry or mountainous regions of the world—parts of Europe and Asia.
After blooming and setting seed, they spend their late summers and autumn safely dormant below ground.
The underground part is technically a corm, a swollen and compact underground stem. The grass-like leaves often have a white stripe running down the middle from base to tip. White, purple, yellow, lavender, even striped, these early bloomers can multiply to create lovely drifts of color, sometimes against the snow.
In Oregon, crocuses seem to be planted mostly in garden beds or borders or in pots. In other parts of the country, they are popular in rock gardens and in lawns. Perhaps in those parts of the country, the grass is slower to grow because mowing is not recommended until at least 4 weeks after blooming ends. With mulch, they can be grown in Zones 3 or 4, but in most of western Oregon, except for higher elevations, mulch is not required for survival.
One species, Crocus sativus, is the saffron crocus, native to southern Europe, is a source of spice— anthers of 7000 flowers are required to make 1 dry ounce. No wonder it is so expensive.
Most crocuses bloom in the spring, but the saffron crocus and a few others, bloom in the autumn.
They have few diseases, however, they are popular edibles by some of our small creatures like gophers and mice. If this is an issue, planting them in wire cages can help.
Douglas Iris (Iris douglasiana)
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Douglas Iris (Iris douglasiana) lives naturally on the south coast of Oregon and in coastal California.
It has a taller stature (about 2 feet) than Iris tenax, the Oregon iris that you see here so commonly in the wild. It has its place in our gardens as both an Oregon native (although not a local one) and a WaterWise plant choice. It is sometimes called Pacific Coast iris, although this name is also applied to a range of hybrid irises of West Coast origin.
Flower colors typically are pale to medium blue, but violet, cream, and white forms are also known. In nature, it often forms clumps, which it will also do in a garden setting. Unlike some other iris, this species does fairly well in part shade, although flowering is more prolific in full sun.
It is widely available at native plant nurseries in Oregon and California and also appears frequently at plant sales featuring native plant.
I have grown this species for many years and am particularly fond of the white form shown in the photograph, but the blue forms also add a cheery note to a garden setting.
Unlike some of the reports in the literature, I have had good success dividing clumps and moving pieces to new locations in the garden. Like many of our natives, this species tolerates, even seems to thrive on summer dry periods and provides a fantastic reward of colorful flowers in mid-to late spring every year.
Dusty Miller
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Senecio cineraria, dusty miller, is one of the most commonly available plants in retail nurseries.
Although sometimes sold as an annual, this USDAS Zone 8-10 plant often overwinters well in our climate; my plants survived even this past very cold winter. It is relatively inexpensive, has striking silver foliage, and is a staple plant for the waterwise garden. One website notes that it “shows up well in the twilight garden” – how romantic.
The gray/silver foliage is a clue to its waterwise tendencies. The color comes from wooly hairs on the surface of the leaves, which also serve to hold in humidity close to the leaf. The reflective color helps keep the leaves from excessive heat in hot, dry climates. Indeed, it is native to the Mediterranean.
It belongs to the sunflower family (Asteraceae) and bears bright yellow flowers in early summer.
Grow this plant alone or mixed with others in full or part sun. Use its colorful foliage to complement or set off other plants.
In Western Oregon, it requires little if any supplemental irrigation, but watch the plants for signs of water stress like wilting. For some good pictures, check out Washington State University.
English Lavender (Lavendula angystifolia)
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If you mention WaterWise gardening to some people, English lavender, Lavendula angustifolia is the first plant that comes to mind.
Perhaps that is because there are so many lovely lavender farms spread over the Northern Willamette Valley—and the word is getting out.
Although English lavender will survive in a more water intensive landscape, perhaps its real value is the drought hardy tendencies. It also qualifies as nearly deer-proof, making it a high value garden plant for more rural gardens.
This species is originally from southern Europe near the Mediterranean but has been become associated with English-style gardens. It has grayish foliage typical of many WaterWise plants and purple flowers. Many cultivars have been developed and include dwarf forms, some with greener foliage, and a wide range of color choices.
It is in the mint family and shares the aromatic characteristics of many of its relatives—in plain terms, it smells good. Generally hardy in USDA Zones 5-8, this species also tolerates poor soils. Plant in a sunny site for the best flowers.
Traditional uses of this plant are varied. For years, flowers have been harvested for their pleasant smells, used to “freshen” linens or mask unpleasant odors. They are reputed to repel insects, and do seem to deter deer from feeding on them. Many other uses since the times of the Roman Empire include medicinal, incense, and as a disinfectant.
Many other species of lavenders are also known in nature and in horticulture, but English lavender will remain many people’s favorite.
Gingko (Gingko biloba)
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Looking for a Water-Wise tree? If you are, you might try ginkgo, known botanically as Ginkgo biloba.
The species name of “biloba” comes from the distinctive leaf pattern, typically with two lobes on fan-shaped leaves with parallel vein patterns. It is a popular pattern for pottery and artwork because of its distinctiveness and beauty.
Originally from Asia, this species comes with a fascinating history. It is a very ancient tree, known extensively from the fossil record and is extinct in wild habitats. In fact, fossils indicate that it once had many living relatives from most continents on earth, including North America.
So how did this species survive to become part of our garden repertoire? According to a website at The University of California, Berkeley, it survived because Buddhist monks in China and Japan cultivated it in their temple gardens as a sacred tree. Individual trees can reach as high as 60 feet and live for a thousand years or more under the right conditions.
If you purchase one for your garden, you will most likely be buying the male form of this dioecious species. The reason is that the female “fruits” surrounding the seed create a very unpleasant smell when they decompose. To quote from the Berkeley website, “In the horticultural literature, it is variously referred to as "disagreeable," ‘evil,’ ‘offensive,’ ‘disgusting’, ‘repulsive’, and "abominable," and is often compared to the odor of vomit. It is due to the malodorous chemical compound butyric acid . . .it is the same compound that gives rancid butter its "distinctive" smell.
This is an ideal tree for Oregon because it does the best in climates that have a Mediterranean pattern of light summer rainfall. It is considered to be relatively free of pests and diseases as well. The fall color, which in the best years is a bright golden yellow, is spectacular.
To learn more and view more pictures, visit the OSU landscape plant site.
Golden Currant
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One of my favorite native plants.
Seeing this species in a local nursery last week reminded me that I have not yet written a profile for this shrub. Although it grows naturally east of the Cascade Mountains in the American West and Western Canada, it performs well in the valleys of Western Oregon. Because of its low water requirements, it also qualifies as a WaterWise plant choice.
Golden currant is s a loosely arching 6-8 ft. deciduous shrub with bright yellow flowers, golden to black fruit, and golden to reddish fall color, earning its common name several times over. The leaves are lobed and light to medium green. It grows well in full sun or part sun, tolerates poor soil, and requires minimal irrigation. Mulching helps the plant maintain full health and flowering potential; additional fertilizer is rarely if ever necessary.
Like other currants, the fruit is edible and this species is often used in breeding new currant varieties. It is a cane bearing shrub, meaning that new branches often arise at the ground level, so prune appropriately by taking out entire “canes” when this is necessary or by cutting back to natural dividing sites of the main branch to eliminate an undesirable side branch. Golden currant blooms in the summer, attracting hummingbirds and insects.
My plant at a previous residence shared a space under an oak tree with a lime green form of mock orange; the combination was stunning.
For more information and pictures, visit the OSU Plant ID site.
Hebes
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The genus Hebe does not immediately bring to mind water conservation.
In fact, most Hebe species and cultivars require moderate water, about the same requirement as most Rhododendron. However, there are some exceptions and they are worth noting.
In general, plants with gray or silver and small leaves are more drought tolerant than plants with bright or dark green foliage and larger leaves. So, if you like Hebe in a more drought tolerant form, simply look for those with smaller and perhaps gray leaves. Next time you visit the Yamhill County Extension Office, check out the two kinds in the WaterWise Demonstration Garden!
The two kinds in our garden are H. pinguifolia ‘Pagei’ with small gray-green leaves and H. ‘Broughton Dome’ with tiny dark green leaves. Both of them came from local nurseries. They both are dwarf shrubs, have smallish white flowers, and small leaves.
Except for the driest of conditions, both kinds have done fairly well. That is a reminder to check the condition of plants periodically, even those known to be drought-tolerant, to make sure they are thriving. Both of these Hebes have also endured the past several winters quite well.
Other species with similar characteristics to consider are H. albicans, H. carnosula, H. glaucophylla, and H. topiaria. If you want to try one of these, be sure to check the hardiness zone and growing characteristics before you buy.
In general, the genus likes full sun, and the drought-hardy ones are no exception. Although some of the more popular forms have purple flowers, the smaller gray-leaved forms seem to have white flowers instead. The genus is native to Australia and New Zealand; given the diversity of habitats in these countries, it is not too surprising that the genus Hebe includes a variety of adaptations as well.
Helianthus Lemon Queen
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Sometimes I stumble across a real “find.”
At a neighborhood garden club plant sale last spring, I picked up two plants labeled Helianthus ‘Lemon Queen.” Without even looking it up (not a recommended practice), I did exactly the right thing. I put the plants about 4 feet apart at the back of the border, in unamended soil and watered sparingly over even the hottest parts of the summer. Starting in late August, I was rewarded with plants over 6 feet high and a profusion of lemony yellow 2-inch flowers that were constantly buzzing with bees.
As I collected seeds over this weekend to see what the next generation of plants might bring, I considered how this delightful plant fits so well into our WaterWise theme.
Helianthus, commonly called sunflower, is an American genus. The most commonly grown sunflowers are annual—most of us are familiar with the stately giants that have become so popular.
However, the genus itself has many perennial species as well, including ‘Lemon Queen.’ The origin of this cultivar is a bit obscure but it probably originated as a natural hybrid somewhere in the Midwest. Often called a “showstopper”, it can grow to 8 feet and tolerates a wide variety of soil conditions. It can withstand very dry soil, giving it the WaterWise designation. Ironically, if given fertilizer it can actually grow taller, but can then become weak and need staking. Again by chance, I did the right thing and the plants were sturdy even in some of our stronger summer winds.
Common names vary, but is often just called “perennial sunflower.” Give it plenty of room in full sun and minimal care, and you too can be rewarded with several months of flowers late in the season, attracting both bees and butterflies of many kinds. Be sure to get the perennial variety since there is an annual sunflower with the same cultivar name.
Hen and Chicks (Echeveria sp.)
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Hen and Chicks (Echeveria sp.)
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Echeveria is an old standby, but a tough plant.
It is another of our WaterWise choices for landscapes or planters. So exactly why did they name that plant hens and chicks? Is it because the “mother” plant makes lots of “baby” plants? To find out, I searched the web and found a very interesting article at Iowa State Extension Service (also the source of the picture).
I already knew of the varied forms of this succulent, but learned that it is native to the mountainous regions of Mexico and South America and that it was discovered by a Spanish botanist named Antanasio Eheverrio Codoy in the 18th century. And sure enough, it was the mother-offset relationship that suggested the common name of “hens and chicks. Check out the website for more interesting facts.
Other websites contain more information. Colorado Extension includes hens and chicks in Xeriscaping choices for rock gardens. These plants do look nice on rock walls and in containers, or any place that the plants and their progeny can nestle into rock crevices or drape over to lower levels. Oregon Horticulture faculty member, Amy Jo Detweiler, recommends this as one of the “fire-safe” plants for Oregon landscapes.
I already grow some in trough concrete planters, but I intend to find more garden spaces for this lovely old fashioned plant from the Central and South America. With all of the great color choices available, perhaps I can collect them all. I will then have plenty to share with my gardening friends.
Incense Cedar (Calocedrus decurrens)
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A sturdy tree for our climate
It’s holiday time, which makes me think Conifers. A WaterWise garden choice is the incense cedar, Calocedrus decurrens. Its pleasant odor when the leaves are crushed is certainly appropriate for the season.
Although not a true cedar, the foliage and form certainly makes us think it is one. Light or reddish bark and a majestic and tall profile add to its appeal. Although it can grow to 100 feet tall, most trees in cultivation do not reach this height. The lush green foliage holds its color well throughout the winter. I’ve seen a lot of these planted in parks as well as by residences and they seem to perform well in both locations.
Perhaps that is because incense cedar is also a Pacific Northwest native plant with a distribution from Oregon and Nevada into California, mostly at higher elevations. It’s beauty and a picture of the cone that allows us to identify it more easily are shown in the photographs from the OSU Plant Identification site, which you can consult for more information and photographs.
Lady Banks Rose (Rosa banksiae)
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Lady Banks Rose Plant
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Rosa is the Latin word for rose
It is one of those delightful words that has made its way into the romance languages and into modern English. Also the word stands primarily for a medium-pink, the color of many wild roses, the genus Rosa has flowers of many colors.
Lady Banks rose, Rosa banksiae ‘Lutea’, has cascades of small, double, pale yellow flowers. Other cultivars can be white. This species rose is a climber, and a beautiful addition to the WaterWise garden. It is termed a “species rose” because it is not the produce of intentional rose cross-breeding—this particular form was introduced from a plant growing in its wild habitat; it is identified by full Genus and species as well as a cultivar name in single quotes.
Native to China, this plant was introduced to English horticulture in the late 1700’s or early 1800s, and over time has been associated with the English form of gardening. It grows in semi-shade to full sun, requires substantially less water than many other roses once established, in generally thornless, and has semi-evergreen foliage. I have seen it scrambling over fences and trained onto trees, a practice popular in England. Early spring is the bloom time.
For more pictures and information, visit Standford University
Mexican Hat
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One of our US prairie natives
Mexican hat (Ratibida columnifera) is often available in retail nurseries and can also be grown from seed. It is a WaterWise plant choice, as are many of the other prairie species like coneflowers and black-eyed Susan.
Mexican hat (often called prairie coneflower ) is a hardy perennial, sometimes dying out in harsh winters, bearing bright yellow to reddish flowering heads in a distinctive sombrero shape, leading to its common name.
At maturity, it will reach 1.5 to 3 feet tall, blending in well with other perennials. Grow in full sun. Many cultivars are available as well as the species form, so search for ones that work best for you.
If you want to grow it from seed, purchase seed and plant it so that you can have plants ready to add to your garden in the summer. Be sure to follow the sowing directions on the seed packet.
Mock Orange (Philadelphus lewisii)
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The genus Philadelphus contains 60 species from many parts of our globe.
That is according to Wikipedia, the online encyclopedia. But when it comes to pictures, what did they choose? You guessed it—Lewis’ mock orange, or Philadelphus lewesii.
That may be because many horticulturists consider it to have the most attractive and fragrant flowers of any member of this group. This species has a wide range through the west, and is reported from Oregon, Washington, Idaho, Montana, and California. It is the state flower of Idaho.
Personally, I’ve seen it in the woods of western Oregon, in full sun along creek sides on Oregon’s eastside, and in the Cascade mountains at relatively high elevation. Also, the specimens growing in my own garden are a delight as they bloom prolifically each spring.
Our species, a member of the Hydrangea family, is named for Meriwether Lewis of Lewis and Clark fame.
Its resemblance to hydrangeas can be seen in the 4-petal formation of the single-flowered forms, and it’s sweet fragrance and arching branches and pure white flower color has made the entire species popular worldwide in wedding bouquets and displays.
This species is commonly described as a multi-stemmed shrub to 10 feet, but I’m pretty sure a yard stick measure would find a greater height in my garden in Beaverton! In my case, I remove suckers and prune for height so as not to hide the view of cars approaching my driveway, however, it can also be pruned as any multi-stemmed shrub by removing about one third of the largest trunks each year. This practice will produce a bushy plant with a shorter overall stature and the arching branches and flowers more at eye level.
Several cultivars of our native species are available—more information can be found by checking out a USDA fact sheet and visit the OSU plant identification site for more information and pictures.
Native Grasses and Sedges
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Native Grasses and Sedges
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Among the many native plants becoming more common in horticulture are the grasses and sedges.
Since many of these species are widespread, check the source of the plants if possible—the closer of origin to your home, the better adapted and more appropriate it will be. All three of these are WaterWise plants—there are more native grasses available, but most are restricted to wetter prairies and require additional water in a landscape.
Although sources of plants may be difficult to find, check with native plant nurseries that may be able to help you locate some plants or do a web search. I was successful at locating several Oregon nurseries that carry plants or seeds by searching on the web.
Idaho fescue (Festuca idahoensis) is one native grass that is relatively commonly available. In its true form it is a bunch grass, but can be mowed if the mower height is kept high. It is native to much of the western United States. A rarer form, F. idahoensis ssp. roemeri, often called Roemer’s fescue, is becoming more commercially available every year from Willamette Valley sources. Sometimes it is referred to as Festuca roemeri. The subspecies has a nice blue-green appear- ance.
Prairie junegrass, Koeleria macrantha, is a widespread grass in North America—Oregon is within its natural range. Junegrass typically grows here in upland prairies, which is an increasingly rare habitat. It grows as a perennial bunch grass, meaning that it forms clumps instead of spreading out as would a typical grass found in lawns. It grows 1-2 feet tall with silvery foliage and attractive flower heads.
More information is available at the plants database for the Lady Bird Johnson Wildflower Center.
Nasturtium (Tropaeoleum majus)
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Nasturtium is such an old standard, common in the gardens of our grandparents and beyond, that it is perhaps difficult to think of this annual as a WaterWise Plant.
We use it in hanging baskets, planted in a sunny border, in pots, and many other areas because of its trailing habit and brilliant color forms. Coming readily and quickly from seed, perking up the garden is about as simple as it gets when one uses nasturtium seed.
Worldwide, more than 50 species are known in South and Central America, but the forms we use were first from Peru and Mexico, making their way to the English in the 16th Century according to a website at the University of Vermont Extension Service. They were first used not only for decoration but for their peppery flavor and they are still often recommended for this purpose.
An internet image search will bring up a seemingly infinite variety or form, some with bright flowers of oranges and reds predominating, and several with variegated leaves, al- though some of the wild forms appear to have white flowers.
Although generally healthy, there are some pests and diseases that can affect nasturtiums. According to University of California at Davis, these may include aphids, cabbage worm larvae, whiteflies and other insects and a few viruses and other diseases.
Remember also that drought tolerance is somewhat relative, so if your nasturtiums show signs of stress, such as wilting, provide the appropriate water they need for survival especially if they are in pots or hanging baskets.
Parsley, Sage, Rosemary & Thyme
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Parsley, Sage, Rosemary & Thyme
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So of these famous herbs from a popular song, only parsley does not qualify as WaterWise.
The son is Simon & Garfunkel, Scarborough Fair, 1966, just in case you don’t recall. The other three—sage, rosemary, thyme—in addition to many other herbs are more additions to the WaterWise plant palette for much of Oregon.
Their forms are varied, from upright, robust forms popular for culinary use, to prostrate, carpet, and other forms favored for ornamental use. All will help make a fine stew, but the cultivars are highly ornamental additions to edible landscapes as well as garden features in their own right.
First, sage. The Princeton WordNet website defines sage in several ways. The first is “a mentor in spiritual and philosophical topics who is renowned for profound wisdom.” Indeed someone with this kind of experience could be helpful in our gardening practices. However, perhaps the more relevant definition is “any of various plants of the genus Salvia; a cosmopolitan herb.”
The herbal species, Salvia, is native to the Mediterranean and has grayish-green leaves. This color is due to whitish hairs on the green leaves. The hairs and the resulting lighter color help reflect light and keep the plant cool in its native environment. The flowers are an attractive bluish purple on short spikes.
The genus is quite large, as many as 900 species. Even of the culinary type, many different cultivars add to garden interest, including the tricolor sage (green, yellow, and white), ‘Purpurascens’ with purple leaves, and ‘Alba” with white flowers (Wikipedia).
Rosemary, Rosmarinus officianalis, is evergreen with dark green, needle-like leaves, and a strong aromatic fragrance. Although rosemary can survive many years in the ground and can be pruned to manage its size, it is perhaps best kept in a pot so it can be brought inside during the coldest part of the winter. The flowers are a medium blue (or pink or white), but unlike sage, these flowers appear along the entire stem at intervals. Many cultivars of rosemary are available, popular ones being prostrate rather than upright.
Then there is thyme—so many kinds with so many uses. The culinary type or common thyme is Thymus vulgaris, native to the Mediterranean. According to the online encyclopedia Wikipedia, this is not the only one used for cooking. Others are especially popular for landscaping are the creeping kind, including wooly thyme (Thymus praecox ssp. arcticus 'Lanuginosus') and creeping thyme (Thymus serphyllum). Find out more about the 400 or more species at Iowa State Extension Service.
Pearly Everlasting (Anaphalis margaritacea)
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Is Anaphalis margaritacea a wildflower? Is it a flower for floral arrangements? Is it a Superweed?
The answer is all in your perspective and they way you grow it. My own answer is that A. margaratacea, commonly known as pearly everlasting, is an attractive native plant that grows very well, and even “behaves itself” in the appropriate garden setting. Also, it is drought tolerant, making it appropriate for a WaterWise garden.
In fact, pearly everlasting is native to much of North America, found in most western and northern states as well as Canada and Alaska. The species exhibits many signs of its drought tolerant nature. The leaves and stems are grayish from fine white hairs. These hairs help regulate moisture levels near the plant’s surface and the color reflects some of the sunlight.
It can be found blooming for most of the summer in our area, with clusters of yellow and white flowers heading up each stem and branch. The end of the bloom season, however, does not mean that they do not remain attractive.
Since this is an everlasting flower, often used in floral arrangements, the flowering heads remain on the plant for a long time. Harvesting them is relatively simple:
- Cut the stems while the flowers are still attractive
- Remove the leaves if you wish
- Bundle them together
- Hang them upside down to dry in a cool and dry location.
For information on drying cut flowers and which different ones might be appropriate, visit this website from the University of Nebraska Cooperative Extension Service.
All sources recommend cutting flowers at their peak of beauty for the best dried flowers. I have seen pearly everlasting used successfully in dried flower wreaths as well as dried flower arrangements, and the flowers hold up well over time.
Growing pearly everlasting is not particularly tricky, but use common sense in choosing your location. This species propagates readily through underground shoots and can colonize an area quickly, especially if you supply ample irrigation. Choose either a site where this characteristic is desired, or plant in a location receiving only limited water. Spread can be managed by hand pulling plants in undesirable locations, but withholding water in the first place is more economical.
Penstemons
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The name “beardtongue” may bring strange images to mind.
So perhaps that is why these WaterWise garden plants go mostly by their genus name, Penstemon, instead. The common name beardtongue refers to the hairy extension that sometimes protrude from the “mouth” of the flower.
Many new varieties are being featured in the marketplace—these plants are indeed remarkable choices for Oregon gardens. Nearly all are drought tolerant. They are generally hardy and have spectacular blooming stalks that favor visits by many pollinators, including hummingbirds, butterflies, and bees. Some species can be short-lived in a garden, but their form, color, and drought hardiness, make them good candidates for replacement every few years.
The genus itself is local, at least in the broad sense. Most species are native to North America from the Rocky Mountains westward. Many penstemons do very well in Westside Oregon gardens, however, the colder temperatures and more porous soils east of the Cascade Mountains favor some species over others.
One favorite recommended for Eastside Oregon gardens is the low-growing Penstemon pinifolius, pine-leaf penstemon, available in both red and yellow flowered forms.
For Westside gardens, look for the Willamette Valley native P.serrulatus at native plant gardens, or cultivars like P. digitalis ‘Huksters Red’ with whiteflowers and reddish leaves, or the cultivars of the plant pictured, P. barbatus, with deep red flowers.
For rock gardens, consider P. cardwellii or P. rupicola—both are dwellers of rocky outcroppings in the Cascade Mountains.
Ponderosa Pine (Pinus ponderosa)
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A commonly held notion is that Ponderosa pine (Pinus ponderosa) is native only east of the Cascades in Oregon. Indeed, as one crosses the mountain passes going east, you are greeted with beautiful forests, with a yellow cast that gives credence to its other common name of “yellow pine.” However, Ponderosa Pine is also native to the west side of Oregon. In times of European settlement, it was found scattered throughout the Willamette Valley, often near stream banks. Also, Ponderosa pine is one of the WaterWise trees for the Willamette Valley.
According to the Oregon Forest Resources Institute, the Ponderosa pine found in the Willamette Valley is genetically very different from trees found in eastern Oregon. The site goes on to note that historically, the range has been significantly reduced by agriculture, but it is capable of growing throughout most of the Willamette Valley. Potentially, it is a valuable tree for use in plantings in or near wetlands and because of its deep tap root, is suited to urban uses as well.
Once it became known that a few remnant populations of the Westside Ponderosa pine still remained, foresters began efforts to collect cones from these stands and propagate seeds to grow plants for distribution and reestablishment. The Willamette Ponderosa Pine Program, whose purpose was to conserve the genetic resources of the Willamette Valley race and propagate plants to become new pine plantations, worked with the Oregon Department of Forestry and other private groups to carry out their program. The results are that the Willamette Valley form of Ponderosa pine is now relatively easy to obtain.
It is offered for sale by many of the Soil and Water Conservation programs in western Oregon and it readily available at native plant nurseries.
If you are seeking one for your own landscape or property, make sure you get the right form. If it is not labeled, it is probably the kind from drier areas of the West.
Purple Cone Flower (Echinacea purpurea)
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This lovely American native has become a garden favorite in the last few decades. And yes, this member of the aster family is also another of our WaterWise garden choices. The photograph shows ‘White Swan,” one of the many garden cultivars now available.
Oregon State University’s plant identification website lists the species as up to 3 feet tall, blooming in July and August. It grows best in full sun and well drained soil. It is also good for cut flowers, and looks especially nice in the back of perennial borders. Purple cone flower attracts butterflies and best of all, it is listed as “trouble free.” The website has good pictures and other information as well.
This species is also well known for its medicinal properties, and a plethora of information is available from university sources about these properties and the scientific studies that support them. An advanced Google search will provide this information if you are interested.
In nature, the species has a broad range throughout much of the southeastern eastern United States. It grows successfully in many horticultural zones, ranging from 3 to 8. Flower colors range from the rose-purple of the wild form, to cultivars in white, pink, and intense pinkish- purple. Relatives of the purple coneflower, i.e., other species of Echinacea, also include yel- low, and are worth trying as a complement to the purple coneflower. This species thrives in poor soil as well.
Propagation is through seed or division at about 3-4 years or longer. Seed is readily available. If you leave the flowers on to go to seed, you will find that it reseeds successfully but not aggressively in the garden.
Purple Leaf Grape
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Vitis vinifera ‘Purpurea’ is a purple-leaf relative of our wine grapes.
Unlike its agricultural relatives, this hardy climbing vine grows to only 30 feet, but it may be pruned to keep it lower. What they have in common is that fall is “their time of year.”
In late October, commercial grapes are ready for harvest, with fruit hanging heavily on the vines. This is also the time when the Purple Leaf Grape is a real show-off with fall color of deep reddish purple. Although this variety also makes fruit, they are considered by some to have a rather unpleasant taste. However, its ornamental features and use as either a climber or as a groundcover, make up for the lack of fruit flavor.
Three years after planting, the two vines in front of the OSU Extension Office in Yamhill County are just beginning to reach eye-catching size. It has been well worth the wait, and many visitors have already commented on them and asked questions. Because of its success and non-invasive characteristics, we featured it in GardenSmart Oregon as an alternative to English Ivy.
Although it adapts to many different soils, growth and color are best in full sun. It is also considered to be WaterWise, so can be used in drought-tolerant landscapes. To add to its credits, the species has also been selected as a “Great Plant Pick” by the Elizabeth Carey Miller Botanical Garden.
Remember, fall is a great time to plant woody trees, shrubs, and vines. Purple Leaf Grape is commercially available in Oregon at specialty nurseries.
Santolina
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Here is another species to add to your list.
The genus Santolina includes several species of horticultural interest; these members of the sunflower/aster family are native to the Mediterranean and do very well in the western valleys of Oregon such as the Willamette Valley. Several species, listed below, are frequently available at local garden centers, usually in 4-inch pots and sometimes situated with the herbs.
They are evergreen shrubs with tiny leaves resembling conifers-one species is silver gray, the other green. Both are low growing and spreading or slightly mounding, acting much like a ground cover. In summer, tiny pom-pom bright yellow flowers cover the plants. I have been growing santolinas for almost 30 years, and will continue to recommend them, even though they are sometimes short-lived. Plant them in full sun with moderate to minimal irrigation once they are established.
The most commonly available one is the gray lavender cotton, S. chamaecy-parissus. As the name suggests, the foliage is silver or gray, making an interesting contrast in the garden. The other one is S. rosmarinifolius (synonym S. virens) with dark green foliage. Give them plenty of room to spread. Sometimes they die out in the middle as they grow, but they are easy to replace with new plants; they are also easy to propagate from cuttings.
For more information about these species and more photographs, visit the OSU Landscape Plant Identification site.
Serviceberry (Amelanchier sp.)
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Serviceberries (Amelanchier sp.) are well known for their fragrant white flower in spring and their reliability as landscape plants.
The most popular serviceberry in the trade is probably the eastern or common serviceberry (Amelanchier arborea), found in many of the eastern states. This species and several other Amelanchier native to North America share their ability to withstand drier garden conditions, making them good candidates for WaterWise gardens. An exception to this is the Allegheny serviceberry (A. laevis) which requires moist soil.
According to Wikipedia, the genus is made up of about 20 species native to North America, Europe, or Asia. All are multistemmed shrubs or small trees, often forming colonies. The fruits are noted as being important as a food source for wildlife. Fall color is generally yellow to red; and the small-sized leaves generally do not require raking.
Our own native is also known as Saskatoon (A. alnifolia). It has a wide distribution in the western states, and the fruits are edible. According to the Wikipedia site, the American Indian food known as pemmican was favored by fruits, including serviceberry, in combination with dried meats. Interestingly, the city of Saskatoon, Saskatchewan in Canada is named after this plant.
Several horticultural selections are sold as cultivars.
The cedar-broom rust and other rust fungi affect many of the serviceberries grown in western Oregon. In some years, the rust is an aesthetic problem, but does not seem to provide long term harm to the plants.
You can find more information and photographs of the native and other species at the OSU plant ID site.
Spanish Lavender (Lavendula stoechas)
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Culinary herb? Deer-resistant landscape plant? Striking perennial border accent?
Yes, Spanish lavender (Lavendula stoechas) is all of these and more. It is yet another choice for our waterwise landscapes here in the Willamette Valley. L. stoechas is sometimes called French lavender, although L. dentata also shares this particular common name, so rely on the scientific designation if possible.
I have been growing this species in my own garden for many years, including the parking strip which receives no supplemental water. When I’m out working in the garden, people often stop to ask about the plant--what it is and where they can they get it. One person even came to a screeching halt as they were driving by to ask the same questions! Fortunately, Spanish lavender is available at many local nurseries, often in 4-inch pots, and sometimes in gallon size, so I was able to answer all of their questions.
L. stoechas is an evergreen shrub or sub-shrub, sometimes dying back to the woody part each year, growing 2-3 feet tall and just as wide. Grow it in full sun, or only a very slightly shaded site. The flowers are larger and showier than those of English lavender, and often a deeper purple as well. Various cultivars are available with more intense colors or different growth forms if you prefer these over the species. After several years, Spanish lavender might benefit from some severe pruning in mid to late spring. It does self-seed in the garden, but not prolifically in our area. This characteristic will provide new plants for your garden and for those of your friends and neighbors as well.
Species Tulips (Tulipa sp.)
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Tulips are in the genus Tulipa, but it often seems that the resemblance stops there.
We can grow extravagant parrot tulips to miniature species tulips and everything in between. The Tulip Festivals now underway in the Willamette Valley remind us of our love for these colorful garden plants.
A bit harder to find than the giant hybrids, but perhaps even easier to grow are a group of tulips that are either still found in wild habitats or are very closely related to them. These are called collectively the “species tulips.” They tend to be smaller, some even “miniature,” but just as colorful. A distinct advantage of growing species tulips is that they often self-seed, creating a naturalized group of tulips in your garden. And they come back year after year.
So here are some to seek out. Griegg’s tulip, (Tulipa greigii) has a short stature (8-12”) but impressive bright red flowers; many other color forms are also available. Tulipa tarda is smaller, perhaps 6 inches high, and has yellow flowers tipped with white. As with many species tulips, the flowers open full and wide on a sunny day. Tulipa kaufmanniana is another shorter but stout species (6-8”) with selections in reds and oranges. Tulipa clusiana flowers range from yellow to pink and white. They are native to Central Asia and the Persian gulf, growing to only 10-12 inches high. A delicate smaller yellow and white tulip growing to only 7 inches is Tulipa turkestanica. For more choices, check out the following website at Iowa State University.
As with many of our garden species, some targeted internet searches can yield lots of information about the history and culture of tulips, so give it a try. Most are of Mediterranean origin, so they appreciate little or no summer water and good drainage. To provide this, make sure the soil is raised slightly above the base ground level and avoid excess irrigation. These plants are welcome and colorful additions to our WaterWise gardening palette, so take the extra time to seek them out and make them part of your landscape.
Stonecrop (Sedum spathulifolium)
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The broadleaf stonecrop, known botanically as Sedum spathulifolium, is one of several sedum species native to Oregon.
Horticulturally, it is one of the best, with many cultivars and color forms readily available at most nurseries. These plants are rarely labeled as natives, so you have to look for the specific names—check out some of the cultivars I refer to later in the article. They work well in rock gardens, raised beds, or any location that has full sun and good drainage.
S. spathulifolium grows in many locations in Oregon, from coastal soils and rocky areas to the Columbia River Gorge, and to other locations in the Cascade and Siskyou Mountains. Those from the Cascades and other inland sites tend to be dark green, while most of the coastal forms are gray or whitish, often highly ornamental—some with red coloring as well. Some of the cultivars to look for are ‘Cape Blanco’, ‘Campbell Lake’, ‘Blood Red’, ‘Moon Glow’ (in photo), ‘Purpureum’, and ‘Carnea’ or you just might prefer the plain green ones. All perform well in garden settings.
Nursery sources describe this species as “spreading but not invasive” or “well-behaved,” both terms I would agree with from personal experience. It is hardy to most of Oregon and, once established, requires little if any supplemental water. Yellow flowers in June attract native butterflies, some of which use the species for the caterpillar host stage.
If you are interested in looking at the distribution yourself, check out the Plant Atlas function at the Oregon Flora Project, a nonprofit organizations using resources of the herbarium at OSU. To use the plant atlas, you have to use botanical names—find “Sedum” in the genus list and double-click it to bring up the species names. Scroll to “spathulifolium” or any of the other native species and add them to the map options form, then generate the map.
Strawberry Tree (Abutus unedo)
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Strawberry Tree (Abutus unedo)
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The strawberry tree, Arbutus unedo offers a kind of dual option by including both a small tree and a dwarf form which grows as a shrub.
And if you are also searching for garden beauty, a WaterWise tree or shrub, maybe even a tree that is suitable under power lines, please read on.
According to the OSU plant identification site, the strawberry tree is an “Evergreen shrub/tree, 8-12(35) ft [2.4-3.6(10.6) m] tall, similar width; red-brown [shaggy] attractive bark.” A member of the Ericaceae or Heath Family, this plant has small, urn-shaped flowers. It is the fruit, however, that sets this species apart as they mature each fall into orange-red and “knobby” spherical shapes. Grow this plant in full sun, well-drained soil.
As some of you may have already noticed, the strawberry tree is related to our own native madrone (Arbutus menzeisii). However, the strawberry tree is native to Europe, ranging from southwestern Ireland to the Mediterranean. It is a great addition to the WaterWise plants that grow well in the Pacific Northwest.
For those who prefer the shrub form, look for A. unedo ‘Compacta.” It grows as a shrub up to 10’ high by 10’ wide, but can be maintained in a shorter more compact form by judicious pruning. For a profile of this plant see the Great Plant Picks featured by the Miller Botanical Garden in Seattle, WA.
Sunflowers (Helianthus sp.)
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The genus Helianthus is named after Helios, the Greek sun god, who in legend was said to travel in a chariot each day across the sky.
Many sunflowers track the sun throughout each day, following Helios’ path. Princeton University's WordNet defines Helianthus as any member of the genus having large flower heads with dark disk florets (the flowers at the center of the head) and showy yellow rays (flowers at the outside ring of the head).
You may recall that the sunflower is indeed made up of a few to hundreds of tiny flowers with the whole flowering head mimicking the appearance of a single large flower.
Helianthus annuus (pictured) is an annual member of the genus with very large and showy flowers, producing the familiar culinary sunflower seeds; a single seed is produced from each flower in the flowering head.
Many cultivars are available, but be aware that any seed produced will most likely revert to the wild form over successive generations. Plants and seeds for the cultivars are generally widely available, and the species will often grow easily from seed.
Finally, the species is native to much of the US and requires little if any supplemental water (making it one of our WaterWise plant choices).
Sword Fern (Polystichum munitum)
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Sword Fern (Polystichum munitum)
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Several ferns are WaterWise and can be grown in drier conditions locally.
Perhaps the most versatile is our very own sword fern, Polystichum munitum. This species grows in many habitats in the Pacific Northwest, but is perhaps most prevalent in shaded forests. However, in gardens, the sword fern can also tolerate moderate to nearly full sun. Once established, additional water is not necessary, although the plants may look more attractive if given a little water during particularly dry times. As with all plants, additional water during the establishment phase is important. For some nice photographs, including the one shown here, go to the OSU plant identification website. That site also mentions a subspecies, Polystichum munitum var. imbricans, which is a shorter form that actually prefers sun over shade.
Sword fern is evergreen, with new fronds unfurling each year during the growing season. For esthetic reasons, some people prefer to prune out the old fronds each year, or even cut back all foliage before the new fronds emerge. This produces a smaller plant overall, which some people prefer as a management tool. On the other hand, it is an extra garden chore (a matter of personal preference) and does remove hiding places for amphibians and beneficial insects.
It is native to western North America, from Alaska to California and east to Montana. Transplanting is nearly always successful, so if you have plenty of ferns on your property, you might consider relocating some into a garden setting. Get ready, however, to spend some time getting the highly fibrous root system free from its native soil. Sword fern is also readily available in nurseries. If you would like to try your hand at propagating them from spores, look for instructions at the following Washington State University website.
Wild Hyacinth (Triteleia laxa)
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Triteleia laxa, also known as Ithuriel's spear or wild hyacinth, or sometimes starflower.
This delightful WaterWise bulb is an Oregon native. Are you surprised? It occurs naturally in southwestern Oregon and throughout much of California. Not quite so surprising is that this little bright-blue flowered bulb does exceptionally well in our gardens. Be aware that wild plants of T. laxa are a protected species in Oregon because of its scarcity here. It is, however, widely available as a commercial bulb, mostly with blue flowers, but sometimes with white or deep purple ones. Cultivars, such as ‘Humbolt star’ and ‘Queen Fabiola’ are available and worth checking out.
The plant has tall stalks, topped by clusters of flowers, blooming in mid-spring. Each flower looked like a six pointed star. The “bulb” is botanically a corm, a short underground swollen stem. These corms were reportedly used as food by native peoples and eaten like potatoes. Although I have not personally seen these for sale in Yamhill County, don’t give up—they may also go by the name Brodiaea laxa. Check out nearby native plant nurseries, check suppliers in the larger metropolitan areas, or go online to find sources for this hardy bulb.
