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Drought-tolerant plantsA selection of shrubs for year-round interest

Neil Bell OSU Extension ServiceMarion and Polk Counties

Ceanothus evaluation, OR Garden 2001-2005 Cistus/Halimium evaluation, NWREC 2004-2009

Manzanita (Arctostaphylos) evaluation 2011-2019 Groundcover evaluation: planted 2019

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Mediterranean Climates

Drought tolerance varies between plants

Grevillea lanigera ‘Coastal Gem’

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Grevillea fililoba

Full sun or some shade?Site factors:

Site aspect

Nearby heat-radiating structures Soil quality: Organic matter, pH, nutrients (P, K) etc.

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Soil compaction Drainage

A plant which, after a short establishmentperiod, will grow and flower normally withminimal or no supplemental irrigation

A drought-tolerant plant is…

Plant selection for year-round interest

• Native flowering plants

• Flowering shrubs

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Silktassel (Garrya elliptica) Zone 8

Chaparral currant (Ribes malvaceum) Zone 7 Chaparral Currant (Ribes malvaceum)

Contorted Hazelnut (Corylus avellana ‘Contorta’) Zone 4 Contorted Hazel (Corylus avellana ‘Red Majestic’)

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Winter-flowering Clematis(Clematis cirrhosa)

Zone 7 C. cirrhosa var. purpurea ‘Freckles’

Sweetbox (Sarcococca confusa and S. hookeriana) Zone 6 Sweetbox (S. confusa)

Sweetbox (S. hookeriana) Sweetbox (S. hookeriana)

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Manzanita: Arctostaphylos spp.

Kinnikinnick (Arctostaphylos uva-ursi) Zone 4

Hairy Manzanita (Arctostaphylos columbiana)

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Hairy Manzanita (Arctostaphylos columbiana)

A. nummularia (select form) Zone 8 A. hookeri ‘Wayside’ Zone 8

A. ‘Sentinel’ Zone 8 Oregon Grape (Berberis aquifolium)

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Oso Berry (Oemleria cerasiformis) Rosemary (now Salvia rosmarinus) Zone 6

Flowering currant (Ribes sanguineum)

Currants and gooseberries

Clove Currant (Ribes aureum)

Fuchsia-flowered gooseberry (Ribes speciosum) Zone 7 Serviceberry -aka “Saskatoon” (Amelanchier alnifolia)

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Thyme (Thymus vulgaris) Zone 7

Rockrose: Cistus and Halimium spp.

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C. x hybridus Zone 7

C. x purpureus Zone 7 C. x pulverulentus ‘Sunset’ Zone 8

Halimium lasianthum ‘Sandling’ Zone 8 C. x obtusifolius Zone 8

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C. x aguilarii ‘’Maculatus’ Zone 8 Sunrose (Helianthemum nummularium ‘Belgravia Rose’) Zone 5

Spanish lavender (Lavandula stoechas) Zone 8

Wild (California) Lilac: Ceanothus spp.

Deer Brush (Ceanothus integerrimus) Redstem Ceanothus (Ceanothus sanguineus)

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C. thyrsiflorus ‘Victoria’ Zone 8 Point Reyes Ceanothus (C. gloriosus) Zone 8

C. ‘Blue Jeans’ Zone 8 C. x delilianus ‘Gloire de Versailles’ Zone 7

Carpet Broom (Genista lydia) Zone 7 Carpet Broom (G. pilosa) (Zone 5)

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Jerusalem Sage (Phlomis fruticosa) Zone 7 Purple Phlomis (Phlomis purpurea) Zone 8

Snowberry (Symphoricarpos albus) Hairy canary clover (Dorycnium hirsutum) Zone 8

Lavender (Lavandula x intermedia) Zone 5

Oregano: Origanum spp.

O. ‘Kent Beauty’O. rotundifoliumO. laevigatum Zone 8

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Roses

Rosa nutkana Rosa (moss type)

Rosa ‘Ispahan’ Rosa ‘Eddie’s Jewel’

Oceanspray (Holodiscus discolor) Sage (Salvia officinalis) Zone 5

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Russian Sage (Perovskia atriplicifolia) Zone 6 Lavender cotton (Santolina chamaecyparissus) Zone 7

S. pinnata ‘Edward Bowles’ Zone 7 Yucca (gloriosa?) Zone 7

Yucca rostrata‘Sapphire Skies’

Zone 8

Our Lord’s Candle:Yucca whipplei

Zone 8

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Chaste Tree (Vitex agnus-castus) Zone 7 California fuchsia (Epilobium canum) Zone 7

Shrubby hare’s ear (Bupleurum fruticosum) Zone 7

Coyote brush (Baccharis pilularis) Zone 8 B. pilularis ‘Twin Peaks’

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Strawberry tree (Arbutus unedo) Zone 7 Strawberry tree (Arbutus unedo)

A. unedo ‘Elfin King’