Successful Water-Wise Gardening: A Brief Overview

Because almost all drought-tolerant plants have a vast, far-reaching root system that seeks out water deep below the soil’s surface, well-amended soil is a must when planting a drought-tolerant garden. Pacific Northwest gardeners are often faced with heavy clay that does not drain well—the demise for many landscape plants. For this reason, compost should be added to native soil if drought-tolerant plants are to survive. Even if you are planting a sloped area, adding about 1/3 compost to 2/3 native soil is imperative; water must soak deep into the soil where, in times of drought, plants’ root systems can have access. Mixing homemade compost and/or G&B Soil Building Conditioner into your native clay soil will greatly improve the texture, aeration, and draining capacity, so this should be your first priority when planting a water-wise garden.

Xeriscaping is a landscaping method specifically designed for water conservation in hot, sunny areas. Whether that be an entire geographic region (e.g. Arizona), or merely areas in your yard, by decreasing the amount of lawn, using native plants, mulching beds, and installing an efficient irrigation system, you will be an active participant in water-wise gardening.

‘Xeros’ is Greek for “dry”, so xeriscape literally translates to “dry landscape”. Gardening in hot, dry situations is most successful when compatible plant choices and cultural practices are engaged. For example, consider decreasing or eliminating the lawn in your yard; think of all the water you won’t consume this summer! Lawns can easily be replaced by any number of drought-tolerant plants, including those native to the Pacific Northwest. Plants that are indigenous to an area are already acclimated to the extremes that weather can bring, making native plants a smart gardening choice.

Though they may be tough and tolerant of a hot, dry, sunny environment, drought tolerant plants do need water—they just use less of it and are more efficient with what they have. Getting plants off to a good start with proper establishment watering can be a critical factor in their ultimate survival. This is particularly true their first season in the ground when extensive root systems must get established. Be prepared to provide supplemental water to newly planted trees, shrubs, and perennials for the first two seasons: particularly during the hottest part of the summer. Watering slowly and deeply will ensure precious water goes deep into the soil instead of running off. The third summer will require you to watch your plants during the hottest days/months, giving them supplemental water every few weeks. At any time, if your plants begin to wilt due to lack of water, give them a drink so as not to cause them (or you) undue stress! By the third or fourth summer, plants should be established enough to fend for themselves but even mature trees, shrubs, and perennial plantings benefit from a deep watering every 3-4 weeks during prolonged periods of heat and drought.

Once your beds are established, you’ll need to set in place an efficient irrigation system. Irrigation options can range from simply laying down soaker hoses to extensive systems professionally installed for you. The goal of an efficient system is to water less frequently, but deeply into the soil. In addition to smart watering, you’ll need to mulch your beds with several inches of bark chips, hazelnut shells, compost, G&B Soil Conditioner, etc. to prevent the soil from drying out too quickly and to promote a healthy soil environment (for microbes, worms, etc.). Always remember to keep mulch away from the trunk or base of plants by about 4 inches for ideal plant health. Need help? Call us! 503.777.7777

Plant Suggestions for Hot, Dry & Sunny Areas

Plants that are native to the Pacific Northwest are noted with ‘(N)’

TREES

  • Madrone/Arbutus menziesii (N): Grows to 35-45’, slow growing; unusual red bark; evergreen leaves; white bell-shaped flowers
  • Western Redbud/Cercis occidentalis (N): 10-18’ tall and wide; deciduous; sweet, pink flowers along branches in spring followed by heart-shaped green leaves
  • Eastern Redbud /Cercis Canadensis: 25-35’ tall and wide; fast growing; deciduous; pink flowers on bare spring branches followed by heart-shaped green leaves
  • Incense Cedar/Calocedrus decurrens (N): Grows to 75-90’ tall and 10-15’ wide at the base; dense, evergreen, fan-shaped sprays of fragrant foliage; reddish bark with interesting texture
  • Deodar Cedar/Cedrus deodora: 40-80’ tall and 40’ wide; fast growing; typically green (some varieties have blue or yellow cast), clustered foliage; soft-looking texture; evergreen
  • Ponderosa Pine/Pinus ponderosa (N): 50-100’ tall and 25-30’ wide; moderate-fast grower; evergreen, stiff green foliage; orange-brown bark
  • Eucalyptus/Eucalyptus spp.: Size varies by species; most have silver or grey leaves and gorgeous bark
  • Fig (edible)/Ficus carica: 20’ tall and wide; fast growers; deciduous; unique, large hand-shaped foliage; edible fruit in summer
  • Cypress/Cupressus spp.: Size varies by species; evergreen, typically green foliage; tough family of plants!
  • Spruce/Picea spp.: Size varies by species (and some species are native); evergreen, fragrant green foliage
  • Silk tree/Albizia julibrissin: 20-35’ tall and wide; fast growing; deciduous; large airy pink flowers in summer
  • Japanese zelkova/Zelkova serrata: 60’ tall and wide; deciduous, elliptical green foliage has jagged edges; smooth grey bark
  • Sweet bay/Laurus nobilis: 12-14’ tall and wide; slow grower; evergreen, multi-stemmed, fragrant leathery green foliage; culinary uses

SHRUBS

  • Smoke bush/Cotinus coggygria: Typically 7-15’ tall and wide; oval foliage colored maroon, purple, green or yellow; billowing puffs of flowers in summer
  • Compact Strawberry bush/Arbutus unedo ‘Compacta’: 8-10’ tall and wide; slow to moderate growing; evergreen; stunning red, peeling bark; oblong, red stemmed dark green leaves; white urn-shaped flowers; yellow (young) and red (mature) fruit (texture like that of strawberry) appear at the same time as flowers in the winter; fruit is edible, but usually bland flavored—birds love them!
  • Crape myrtle/Lagerstroemia indica: 4-25’ tall and wide (varies by variety); deciduous; attractive peeling bark; late summer flowers of white, pink, or red; fall color
  • Oregon myrtle or California wax myrtle/Umbellularia californica (N): 6-15’ tall and wide; evergreen, dark green leaves; suitable as a hedge
  • Rockrose/Cistus spp.: 2-5’ tall and wide; evergreen, attractive foliage is green, silver or greyish (some varieties are wooly); profusion of pink or white flowers spring into early summer
  • Manzanita/Arctostaphylos spp.(some N): Size varies by species (from groundcover to tree-like shrubs); evergreen; crooked branches with smooth red to purple bark; white to pink urn-shaped flowers in late winter to early spring followed by red or brown fruit—birds love them!
  • Barberry/Berberis spp.: 1.5-10’ tall and wide (varies by species and variety); most are deciduous but some are evergreen; dense and spiny stems; foliage color varies: red, orange, yellow, purple, green
  • California lilac/Ceanothus spp.: 1.5-15’ tall and wide (varies by species and variety); generally evergreen, foliage ranges from tiny to big and is variant in green coloration; typically flowers in spring—white, pale blue, powdery blue, deep violet blue color varies by species and variety
  • Juniper/Juniperus spp.: Size varies by species and variety; evergreen, green or blue stiff foliage; tough family of plants!
  • Oregon Grape/Mahonia aquifolium (N): 6’ tall and 5’ wide; evergreen, glossy green holly-like foliage; bronzy new growth; purplish winter color; yellow flowers in spring followed by edible bluish-black fruit (birds love them!)
  • Escallonia/Escallonia spp.: 2-15’ tall and wide (varies by species); evergreen, glossy dark green foliage; pink or white summer flowers
  • Silk tassel/Garrya elliptica (N): 4-10’ tall and wide; evergreen, elliptical foliage has wavy edges; long, silky, tassel-like flowers appear in winter and persist into spring
  • Lavender/Lavendula spp.: Size varies by species and variety; evergreen; fragrant pale to dark purple, pink or white flowers all summer; culinary uses
  • Rosemary/Rosmarinus officinalis: Size varies by variety; evergreen, fragrant green foliage; culinary uses
  • Snowberry/Symphoricarpos albus (N): 2-6’ tall and wide; deciduous, roundish green foliage; pink flowers are followed by white fruit that persists over the winter
  • Red flowering currant/Ribes sanguineum (N): Grows to 5-12’ tall and wide; fast growing; deciduous, foliage shape resembles that of maples and is dark green; gorgeous drooping pink flowers in spring
  • Yew/Taxus spp.: Size varies by species and variety, of which there are many; slow growing; evergreen, dark green foliage

PERENNIALS

  • Western Columbine/Aquilegia formosa (N): 1.5-3’ tall and 1.5’ wide, lacy green foliage; nodding red and yellow flowers in spring
  • Goldenrod/Solidago (N): 1.5-3’ tall and 1.5-2’ wide; leafy stems held on woody branches; branching clusters of small, bright yellow flowers in late summer
  • Yarrow/Achillea millefolium (N): Narrow, green or greyish leaves; flat flower heads held on 1.5-2’ stems; various colors available; long summer bloom time
  • Butterfly weed/Asclepias tuberosa: 3’ tall and 1’ wide; multiple stems hold clusters of bright orange flowers that are irresistible to butterflies!
  • Sea holly/Eryngium amethystiunum: Grows to 2.5’ tall and 1.5’ wide; spiny leaves of medium green; silvery blue stems hold conical bluish-purple flowers in summer
  • Blanket flower/Gaillardia x grandiflora: 2-4’ tall and 1.5’ wide; rough greyish-green foliage; daisy-shaped flowers in shades of red and yellow with orange or maroon band; long summer bloom time
  • Cone flower/Echinacea: 1.5-4’ tall and 1.5-2’ wide; daisy-shaped flowers with dome-like centers are held on long, stiff stems above oblong, bristly green, clumping foliage; wide range of flower color
  • Red-hot poker/Kniphofia spp.: 1.5-5’ tall and 2-3’ wide; dense clumps of grass-like green foliage; torch-shaped flowers borne on bare stems; blossoms open bottom to top and change color as they mature
  • Russian sage/Perovskia atriplicifolia: 3-4’ tall and wide; woody base gives rise to multiple upright stems covered in grey-green foliage; sprays of small lavender-blue flowers late spring through summer
  • Jerusalem sage/Phlomis fruticosa: Grows to 4’ tall and wide; wooly grey-green leaves; deep yellow ball-shaped flowers along the upper half stems spring through summer (must lightly cut back after each flowering for repeat bloom); quite unique addition to the garden
  • Wallflower/Erysimum spp. and hybrids: Narrow foliage; clusters of 4-petaled flowers (wide range of colors) nearly 12 months of the year
  • California fuchsia/Zauschneria californica: 6”-4’ tall (variety dependent) and 3-4’ wide; upright or arching habit; narrow green leaves, orange to red flowers in summer; hummingbirds can’t resist them!
  • Verbena/Verbena bonariensis: 3-6’ tall and 1.5-3’ wide; grown as an annual that readily self-sows (reseeds), green foliage stays low to the ground, tall, airy, branching stems carry small, tubular purple flowers in summer
  • Tickseed/Coreopsis grandiflora: 1-2′ tall and 3’ wide; narrow dark green foliage; long slender stems hold daisy-shaped flowers; long summer bloom time
  • Sage/Salvia spp.: Size varies by species and variety; green to grey to yellow foliage; all have square stems and whorls of two-lipped flowers along stalks; wide range of flower color; spring to summer bloom time
  • Cape Fuchsia/Phygelius spp.: 3-4’ tall and wide; dark green, oval leaves have finely toothed edges; drooping tubular flowers in a variety of colors; blooms summer to fall; hummingbird magnet!
  • Baby’s breath/Gypsophila paniculata: Grows to 3’ tall and wide; slender, pointed green foliage on stiff stems; hundreds of tiny white flowers bloom in sprays giving a billowy appearance

ORNAMENTAL GRASSES

  • California fescue/Festuca californica (N): 2-3’ tall and 1-2’ wide; loose clumps of blue-green or blue-grey foliage; airy flowers appear in late spring/early summer
  • Tufted hair grass/Deschampsia caespitosa (N): 1-2’ tall and 2’ wide; clumps of dark green, narrow foliage; airy flowers appear in late spring/early summer
  • Blue oat grass/Helictotrichon sempervirens: 2-3’ tall and wide; semi-evergreen to evergreen, graceful fountain-like clumps of narrow blue-grey foliage; wispy, straw-colored flowers arrive in spring
  • Japanese silver grass/Miscanthus sinensis: 2-5’ tall and 2-8’ wide (many varieties); broad or narrow clumping leaves in varying shades of green; flowers in summer and looks like silky tassels
  • Switch grass/Panicum virgatum: 4-7’ tall and 2-4’ wide; narrow, deep green clumping foliage; slender flower clusters open to airy clouds beginning in mid-summer
  • Black mondo grass/Ophiopogon planiscapus ‘Nigrescens’: 8” tall and 1’ wide; tufts of narrow foliage that emerges green and quickly turns to black; bell-shaped white or pale purple flowers in summer are followed by black fruit
  • Feather reed grass/Calamagrostis x acutiflora ‘Karl Foerster’: 2-3’ tall and somewhat wider; arching, narrow clump of bright green leaves; buff-colored flowers emerge in late spring/early summer and can rise to 6’ tall

GROUNDCOVER

  • Creeping mahonia/Mahonia repens (N): Grows to 1’ tall and 3’ wide; evergreen, dull blue-green leaves take on bronzy-purple coloration during fall and winter; mid to late spring clusters of yellow flowers followed by blue berries
  • Oregon stonecrop/Sedum oreganum (N): Less than 6” tall and 6”-1’ wide; fleshy green, mat-forming leaves that turn bronzy-purple in fall; bright yellow flowers in summer
  • Bearberry or kinnikinnick/Arctostaphylos uva-ursi (N)
  • Oregon grape/Mahonia aquifolium (N): 6’ tall and 5’ wide; evergreen, glossy green holly-like foliage; bronzy new growth; purplish winter color; yellow flowers in spring followed by edible bluish-black fruit (birds love them!)
  • Beach strawberry/Fragaria chiloensis (N): 6-12” tall and 1-2’ wide; 3-lobed glossy green leaves; white flowers in spring followed by small, red edible fruit
  • Creeping juniper/Juniperus horizontalis: 1’ tall and 2-4’ wide; evergreen, grey-green to bluish foliage
  • Lithodora/Lithodora diffusa: 6-12” tall and 2’ wide, evergreen, small deep green leaves; rich indigo blue flowers in spring
  • Thyme/Thymus spp.: 3-6” tall and 6”-1’ wide; evergreen, wide variety of foliage color; tiny flowers through summer; culinary uses
  • Candytuft/Iberis sempervirens: 1’ tall and 1-2’ wide; evergreen, tiny dark green leaves; abundant white flowers at branch tips in spring and sporadically through summer
  • Pinks/Dianthus spp.: Size varies by species and variety; primarily evergreen, grass-like green, blue-green foliage; fragrant flowers of various colors in spring into early summer
  • Bearberry/Cotoneaster dammeri cotoneaster: 8” tall and 10’ wide; woody branches hold small, bright, glossy green foliage; bright red fruit