{"id":9982,"date":"2025-05-21T16:07:24","date_gmt":"2025-05-21T23:07:24","guid":{"rendered":"https:\/\/extension.wsu.edu\/wallawalla\/?p=9982"},"modified":"2025-10-06T07:00:34","modified_gmt":"2025-10-06T14:00:34","slug":"trees-shrubs-and-perennials-for-arid-alkaline-regions-hardy-in-zones-5-6","status":"publish","type":"post","link":"https:\/\/extension.wsu.edu\/wallawalla\/trees-shrubs-and-perennials-for-arid-alkaline-regions-hardy-in-zones-5-6\/","title":{"rendered":"Trees, Shrubs, and Perennials for Arid, Alkaline Regions, Hardy in Zones 5-6"},"content":{"rendered":"\n

TREES & SHRUBS<\/strong><\/h2>\n\n\n\n

Serviceberry – Amelanchier alnifolia<\/em><\/strong><\/p>\n\n\n\n

Multi-stemmed shrub or small tree; 10-12 ft tall, 20 feet wide<\/p>\n\n\n\n

Small white flowers, blueberrylike berries, fall color<\/p>\n\n\n\n

Low water, but may require watering during dry spells<\/p>\n\n\n\n

Suckers readily<\/p>\n\n\n\n

Blue Mist Spirea \u2013 Caryopteris x clandonensis<\/em><\/strong><\/p>\n\n\n\n

Late summer blue color; attracts butterflies and bees<\/p>\n\n\n\n

2-3 ft tall, 3 ft wide; deciduous<\/p>\n\n\n\n

Requires occasional deep soaking, but is generally adaptable to dry conditions<\/p>\n\n\n\n

Catalpa<\/em> species<\/strong><\/p>\n\n\n\n

Moderate to fast growing to 40-70 ft, 20-40 ft wide<\/p>\n\n\n\n

Well adapted to extremes of heat and cold; leafs out late in spring<\/p>\n\n\n\n

Low to moderate water; benefits from deep watering during prolonged drought<\/p>\n\n\n\n

Large, white flowers early summer, bean-shaped seed capsules \u2013 somewhat messy<\/p>\n\n\n\n

Hackberry \u2013 Celtis occidentalis<\/em><\/strong><\/p>\n\n\n\n

Broad, oval shape to 50-60 ft., spread to 40-50 ft., small orange-red fruit<\/p>\n\n\n\n

Once established needs little supplemental water<\/p>\n\n\n\n

Prone to Hackberry nipplegall on leaves but does no harm to tree<\/p>\n\n\n\n

Green Ash \u2013 Fraxinus pennsylvanica  <\/em><\/strong>(seedless male clones best)<\/p>\n\n\n\n

50-60 ft. tall, 30-40 ft. wide<\/p>\n\n\n\n

Tolerates moist to dry conditions \u2013 slower growing in dry conditions<\/p>\n\n\n\n

Susceptible to leaf curl, ash aphid, scale; susceptible to borers if drought stressed<\/p>\n\n\n\n

Juniperus species<\/strong><\/p>\n\n\n\n

Evergreen foliage, small berry-like cones<\/p>\n\n\n\n

Little to moderate water; well-drained soil<\/p>\n\n\n\n

Beauty Bush \u2013 Kolkwitzia amabilis<\/em><\/strong><\/p>\n\n\n\n

Deciduous shrub 6-10 ft., spreads 4-8 ft.; finely branched, multiple upright stems, early summer flowers<\/p>\n\n\n\n

Gray-green leaves to 3 in. long sometimes turn reddish in fall<\/p>\n\n\n\n

Moderate drought tolerance, best with occasional deep soaking<\/p>\n\n\n\n

Golden Raintree \u2013 Koelreuteria paniculata<\/em><\/strong><\/p>\n\n\n\n

Smaller accent tree to 20-30 ft., spread 25-35 ft.<\/p>\n\n\n\n

Midsummer flowers, lantern-shaped seedpods<\/p>\n\n\n\n

Once established, will do well on low to moderate quantities of water<\/p>\n\n\n\n

Pinus specie<\/strong><\/p>\n\n\n\n

P. aristata<\/em> (bristlecone pine), P. ponderosa<\/em> (Ponderosa pine), P. mugo<\/em> (mugo pine), P. nigra<\/em> (Austrian pine)<\/p>\n\n\n\n

Most tolerate alkaline soil as long as well-drained; does well with little water once established<\/p>\n\n\n\n

Potentilla, Cinquefoil \u2013 Potentilla fruticosa<\/em><\/strong><\/p>\n\n\n\n

1-4 ft. high, 2-4 ft. wide<\/p>\n\n\n\n

Good drought tolerance; performs best with additional moisture beyond natural precipitation<\/p>\n\n\n\n

White to yellow to orange flowers throughout summer<\/p>\n\n\n\n

Western Sand Cherry \u2013 Prunus besseyi<\/em><\/strong><\/p>\n\n\n\n

Spreading, open, airy, upright branches forming rounded or vaselike shape<\/p>\n\n\n\n

3-6 ft. tall and wide<\/p>\n\n\n\n

Small white flowers early summer, red fall color<\/p>\n\n\n\n

Three Leaf Sumac \u2013 Rhus trilobata<\/em><\/strong><\/p>\n\n\n\n

Deciduous shrub to 3-6 ft., spreading 3-6 ft., fall color<\/p>\n\n\n\n

Plants sucker from roots \u2013 good for erosion control on difficult sites<\/p>\n\n\n\n

One of the most drought tolerant sumacs, but grows better with additional moisture<\/p>\n\n\n\n

Spirea<\/em> species<\/strong><\/p>\n\n\n\n

Deciduous shrubs to 6-8 ft, spreading 5-10 ft.; smaller varieties available<\/p>\n\n\n\n

Adapts to dry conditions but best flowering with extra water<\/p>\n\n\n\n

Common Lilac \u2013 Syringa vulgaris<\/em><\/strong><\/p>\n\n\n\n

Deciduous shrub to 8-20 ft. with spread to 6-15 ft.<\/p>\n\n\n\n

Fragrant purple flowers in spring<\/p>\n\n\n\n

Performs best with additional water but drought tolerant once established<\/p>\n\n\n\n

Viburnum, Wayfaring Tree \u2013 Viburnum lantana<\/em><\/strong><\/p>\n\n\n\n

Deciduous shrub to 10-15 ft. tall, 10-15 ft. wide<\/p>\n\n\n\n

Spring flowers, fall color, berrylike fruit<\/p>\n\n\n\n

Low to moderate water<\/p>\n\n\n\n

PERENNIALS<\/strong><\/h2>\n\n\n\n

Hummingbird Mint – Agastache cana<\/em><\/strong><\/p>\n\n\n\n

Showy perennial to 2-3 ft, spreads 1.5-2 ft<\/p>\n\n\n\n

Low to medium water, well-drained<\/p>\n\n\n\n

Also A. foeniculum, A. barberi, A. cana<\/em><\/p>\n\n\n\n

Yarrow \u2013 Achillea species<\/em><\/strong><\/p>\n\n\n\n

Herbaceous perennial from 2 inches to 4 ft., spreads 6 inches-3 ft.; tend to spread<\/p>\n\n\n\n

Long bloom period, foliage aromatic<\/p>\n\n\n\n

Well-drained soil; moist to start and dry once established<\/p>\n\n\n\n

Basket-of-gold \u2013 Aurinia saxatile<\/em><\/strong><\/p>\n\n\n\n

Perennial to 6-18 inches tall, 6-12 inch spread<\/p>\n\n\n\n

Low to moderate water, well-drained soil<\/p>\n\n\n\n

Bluebell – Campanula rotundifolia<\/em><\/strong><\/p>\n\n\n\n

Herbaceous perennial to 6-24 inches: sprawls, self seeds, blue bell-like flowers<\/p>\n\n\n\n

Low to medium water<\/p>\n\n\n\n

Red Valerian, Jupiter\u2019s Beard, Fox Brush \u2013 Centranthus rubber<\/em><\/strong><\/p>\n\n\n\n

Bushy clump to 2-3 ft tall 18-24 inches wide<\/p>\n\n\n\n

Reddish pink to crimson flowers late spring and again in mid to late summer; attracts butterflys<\/p>\n\n\n\n

Low to moderate water<\/p>\n\n\n\n

Blanketflower \u2013 Gaillardia aristata<\/em><\/strong><\/p>\n\n\n\n

Vigorous, easy perennial, 2-3 ft. high and wide<\/p>\n\n\n\n

Blooms all summer, good cut flower<\/p>\n\n\n\n

Reseeds but usually not true to type<\/p>\n\n\n\n

Iris<\/em> hybrids<\/strong><\/p>\n\n\n\n

Well-drained soil; tolerates considerable drying and exposure<\/p>\n\n\n\n

Blooms late spring, early summer; many colors<\/p>\n\n\n\n

Catmint \u2013 Nepeta x faassenii <\/em><\/strong>(sterile hybrid)<\/p>\n\n\n\n

Herbaceous perennial to 18 inches high, 30 inches wide<\/p>\n\n\n\n

Good groundcover, lavender-blue flowers<\/p>\n\n\n\n

Other varieties invasive: N. cataria<\/em> (catnip), N. mussinii<\/em> (catmint), N.f<\/em>. \u2018Blue Wonder\u2019, N.f<\/em>. \u2018Six Hills Giant\u2019<\/p>\n\n\n\n

Russian Sage \u2013 Perovskia atriplicifolia<\/em><\/strong><\/p>\n\n\n\n

Shrubby perennial to 3-5 ft. high and 3-4 ft. wide<\/p>\n\n\n\n

Sage-like aroma, silvery gray leaves, lavender-blue flowers attract bees and butterflies<\/p>\n\n\n\n

Takes any soil as long as drainage is good; extremely resistant to drought and heat.<\/p>\n\n\n\n

Prairie Coneflower, Mexican Hat \u2013 Ratibida columnifera<\/em><\/strong><\/p>\n\n\n\n

Herbaceous perennial 18-24 inches tall, 12-18 inches wide; Sunflower family<\/p>\n\n\n\n

Well-drained, very little water; tolerates poor soil<\/p>\n\n\n\n

Garden Sage \u2013 Salvia officinalis<\/em><\/strong><\/p>\n\n\n\n

Herbaceous shrublike perennial 18-24 inches tall, 12-18 inch spread<\/p>\n\n\n\n

Colorfull, long-lasting flowers<\/p>\n\n\n\n

Handles drought well once established<\/p>\n\n\n\n

Lavender Cotton – Santolina chamaecyparissus<\/em><\/strong><\/p>\n\n\n\n

Subshrub, ground cover, 12-18 inches tall, spreading 12-18 inches<\/p>\n\n\n\n

Tolerates heat, wind, alkaline soil<\/p>\n\n\n\n

GRASSES<\/strong><\/h2>\n\n\n\n

Blue Fescue \u2013 Festuca ovina glauca<\/em><\/strong><\/p>\n\n\n\n

Fine-textured, compact blue clumps<\/p>\n\n\n\n

Tolerates dry conditions, looks better with some irrigation<\/p>\n\n\n\n

Blue Oat Grass, Blue Avena Grass \u2013 Helictotrichon sempervirens<\/em><\/strong><\/p>\n\n\n\n

Ornamental perennial grass to 2-4 ft. tall in bloom, 3 ft. spread<\/p>\n\n\n\n

Well-drained soil, indifferent to pH, requires moderate water<\/p>\n\n\n\n

Maiden Hair Grass – Miscanthus sinensis<\/em> \u2018Gracillimus\u2019<\/strong><\/p>\n\n\n\n

Perennial ornamental grass to 6-8 ft. tall, spreading 3-6 ft.<\/p>\n\n\n\n

Most drought tolerant variety<\/p>\n\n\n\n

Indian Ricegrass \u2013 Oryzopsis hymenoides<\/em><\/strong><\/p>\n\n\n\n

Ornamental bunch grass, 1-2 ft. high, spreads 2-3 ft.<\/p>\n\n\n\n

Needs well-drained soil, tolerates drought and heat<\/p>\n\n\n\n

Fountain Grass \u2013 Pennisetum alopecuroides<\/em><\/strong><\/p>\n\n\n\n

Ornamental grass to 2-3 ft. high, spreading 2-3 ft.<\/p>\n\n\n\n

Low to moderate water, tolerates wind and heat.<\/p>\n\n\n\n

Walla Walla County WSU Extension Bulletin #215                                                          5\/06 revised 5\/25<\/p>\n","protected":false},"excerpt":{"rendered":"

TREES & SHRUBS Serviceberry – Amelanchier alnifolia Multi-stemmed shrub or small tree; 10-12 ft tall, 20 feet wide Small white flowers, blueberrylike berries, fall color Low water, but may require […]<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_wsuwp_accessibility_report":null,"_external_link":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/posts\/9982"}],"collection":[{"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/comments?post=9982"}],"version-history":[{"count":2,"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/posts\/9982\/revisions"}],"predecessor-version":[{"id":10382,"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/posts\/9982\/revisions\/10382"}],"wp:attachment":[{"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/media?parent=9982"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/categories?post=9982"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/extension.wsu.edu\/wallawalla\/wp-json\/wp\/v2\/tags?post=9982"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}