Drought-tolerant native evergreens give year-round interest

Oregon grape
Oregon grape (Photo courtesy of James Perkins - Flickr: OpalMirror)
Last Updated: 
January 12, 2012

CORVALLIS, Ore. – With its wet winters and dry summers, western Oregon is well-suited for the water-efficient Mediterranean style of gardening that relies on plants to store water through the winter and survive the summer with little or no irrigation.

“Native, drought-tolerant evergreens do well in a Mediterranean garden because they have adapted to our seasonal pattern of wet and dry,” said Linda McMahan, an Oregon State University Extension horticulturist. She recommends several evergreens to keep a Mediterranean garden green year round.

Oregon grape (Mahonia aquifolium) is native to the West Coast from British Columbia to northern California. With shiny, dark green leaves that look like holly, it grows to six feet. Several can be planted together and pruned as a hedge. The leaves are sharply spiked, and birds are attracted to its yellow blooms and purple berries.

Native to dry, open, rocky areas, common juniper (Juniperus communis) has stiff needle-like leaves and purple berries. It forms a low-growing dense mat. Common juniper tends to have sparse foliage and needs good drainage and very little summer irrigation. Junipers often fail with too much moisture.

Oregon boxwood (Paxistima myrsinites), with its dark green, shiny leaves, can survive Willamette Valley summers with little summer watering if shaded during the hottest part of the day. Its growth varies from low-growing to upright.

Arbutus menziesii, our native madrone, is unique to the Pacific Northwest. It is difficult to transplant because of its reliance on fungal hyphae (which, together with the plant roots, form a system called mychorrizae.) If you are lucky enough to have a madrone in your garden already, McMahan suggests making it a focal point in your Mediterranean garden.

A close relative to madrone, the smaller Arbutus unedo (strawberry tree), has dark green leaves and reddish bark. Native to southern Europe, it is a popular lawn and garden tree in California. As a single tree, it grows slowly to about 30 feet. Or several strawberry trees can be planted close together and pruned as a hedge or screen.

Similar in appearance to Arbutus, manzanitas (Arctostaphylos) are a large group of evergreen shrubs native to western North America. Manzanitas have shiny, dark green leaves and twisted branches with reddish bark. One of the most popular varieties is kinnikinnick (A. uva-ursi). With small, shiny, dark green leaves, it forms a low-growing dense mat up to 15 feet across with small white or pink flowers in the spring followed by red berries. Several cultivars of kinnikinnick are for garden use.

Some evergreens native to Mediterranean climates, such as Cistus,  (also known as rock rose) actually grow best without summer water. Sun-loving and hardy, Cistus varieties range from dwarf to six feet tall, with blooms from red to pink to white, blooming from May into late fall, often with gray green foliage. Cistus grows well in poor soil and requires good drainage.

Rosemary (Rosmarinus), the familiar culinary herb, is another evergreen Mediterranean native with varying forms and heights, from small and rounded to upright and six feet. Like Cistus, it is sun-loving, adapted to poor soils, doesn’t appreciate extra water and requires good drainage.

To view photos of these evergreens, visit the OSU Department of Horticulture’s “Landscape Plants—Images, Identification and Information” website.

Author: Judy Scott
Source: Linda McMahan