The humble groundcover A new look at an old landscape staple Definition of a groundcover Weed management Groundcovers for un-irrigated landscapes Neil Bell OSU Extension Service Marion and Polk Counties Ground cover: a definition In horticulture, ground covers may be considered to be those perennial plants, usually requiring minimal maintenance, that may be substituted for lawn grasses on special sites where the latter normally do not thrive or where lawn maintenance becomes difficult, as in dense shade, on steep slopes or terraces and on sandy or rocky soil where water is not available. Hortus Third, 1976 1 2 Longleaf Mahonia (Mahonia nervosa) Dome Rock, Willamette National Forest 3 4 Juniper: glyphosate damage Birch: phenoxy herbicide damage The things broad-leaved ground covers do… • Suppress weeds • Prevent soil compaction • Add organic matter to soil (also N in some cases) • Add aesthetic value to the landscape • Provide pollen and nectar to pollinators 5 Creeping Juniper (Juniperus horizontalis) Creeping Phlox (Phlox subulata) Strawberry (Fragaria spp.) Hosta, etc. 6 Sedum spp. Carpet Broom (Genista sp.) Cotoneaster (Cotoneaster sp.) Olivier Filippi Pepiniere Filippi Meze, France http://www.jardin-sec.com/ St. Johns Wort (Hypericum perforatum) 7 Rosemary (Rosmarinus officinalis ‘Punta di Canelle’) Olivier Filippi garden, Meze, France Argyle Winery, Dundee, OR Rockrose (Cistus x hybridus) 8 David’s Viburnum (Viburnum davidii) Periwinkle (Vinca sp.) Vinca sp. 9 Cotoneaster, Shrub Dogwood and Western Redcedar, Salem, OR Creeping Mahonia (Mahonia repens) Cistus x hybridus Creeping Mahonia (Mahonia repens). Columbia River Gorge 10 Longleaf Mahonia (Mahonia nervosa) Oregon Grape (Mahonia aquifolium ‘Compacta’ (?)) Oregon Grape (Berberis aquifolium) Creeping Mahonia (Mahonia repens) and Cotoneaster (Cotoneaster sp.) Salal, Creeping Mahonia and Strawberry, West Salem Long leaf Mahonia (Mahonia nervosa) 11 Oregon Grape (Mahonia aquifolium ‘Compacta’ (?)) Longleaf Mahonia (Mahonia nervosa) Oregon Grape (Mahonia aquifolium). Mosier, OR Kinnikinnick (Arctostaphylos uva-ursi) Kinnikinnick (Arctostaphylos uva-ursi) Kinnikinnick (Arctostaphylos uva-ursi) 12 Kinnikinnick (Arctostaphylos uva-ursi ‘Massachusetts’) Arctostaphylos uva-ursi ‘Anchor Bay’ Salal (Gaultheria shallon) Sweetbox (Sarcococca spp.) Sweetbox (Sarcococca confusa and S. hookeriana) Sweetbox (S. confusa) 13 Sweetbox (S. hookeriana) Sweetbox (S. hookeriana) Heath (Erica sp.) Winter Heath (Erica carnea and E. x darleyensis) Rosmarinus officinalis (trailing type) Rosemary (Rosmarinus officinalis): trailing type 14 Manzanita: Arctostaphylos spp. European Honeybee on Arctostaphylos ‘Austin Griffiths’ Glossy leaf manzanita: Arctostaphylos nummularia (select form) A. hookeri ‘Wayside’ 15 Mt. Vernon Laurel (Prunus laurocerasus ‘Mt. Vernon’) Cotoneaster (Cotoneaster ‘Emerald Sprite’) Rockrose: Cistus and Halimium spp. Cotoneaster (Cotoneaster ‘Emerald Beauty’) 16 C. x hybridus C. x purpureus C. x pulverulentus ‘Sunset’ 17 Rockrose (Cistus ‘Grayswood Pink’) C. x obtusifolius Halimium lasianthum ‘Sandling’ Sunrose: Helianthemum nummularium ‘Ben More’ Sunrose (Helianthemum nummularium ‘Belgravia Rose’) Spanish lavender (Lavandula stoechas) 18 Point Reyes Ceanothus (Ceanothus gloriosus) Point Reyes Ceanothus (Ceanothus gloriosus) Wild Lilac (Ceanothus ‘Tilden Park’) Wild Lilac (Ceanothus gloriosus var. porrectus) Wild Lilac (Ceanothus ‘Joan Mirov’) Wild Lilac (Ceanothus gloriosus ‘Emily Brown’) 19 G. pilosa Carpet Broom (Genista lydia) Jerusalem Sage (Phlomis fruticosa) Phlomis angustifolia Lambs Ears (Stachys byzantina) St. John’s Wort (Hypericum calycinum) 20 Creeping Raspberry (Rubus hayata-koidzumii) Creeping Thyme (Thymus coccineus) Thyme (Thymus vulgaris) Hairy canary clover (Dorycnium hirsutum) Lavender (Lavandula x intermedia) 21 Oregano: Origanum spp. Star Jasmine (Trachelospermum jasminoides) O. rotundifolium‘Kent Beauty’ Rose (Rosa rugosa) Sage (Salvia officinalis) Mountain Sage (Salvia microphylla) 22 Lavender cotton: Santolina spp. S. chamaecyparissus S. pinnata ‘Edward Bowles’ Heather (Calluna vulgaris) California fuchsia: Epilobium cana 23 Shrubby hare’s ear (Bupleurum fruticosum) Glossy Abelia (Abelia grandiflora): dwarf forms Coyote brush (Baccharis pilularis) B. pilularis ‘Twin Peaks’ Cistus x hybridus with Taxus sp. 24 Ceanothus and Cistus spp. 25.