When choosing plants for your slope, erosion control and slope stabilization are primary concerns.
Make sure to use deep rooted shrubs and trees along with the more shallow rooted ground covers. You want the more shallow rooted ground covers to help cover the slope, but need deep rooted plants as well to help stabilize the slope.
Don’t simply cover your slope with ice plant or red apple. They have shallow roots and their leaf mass can get so heavy after rains that they can actually pull down the slope.
Native plant choices – ground covers and large shrubs:
Mrs. Beard creeping sage -1 ft. tall by 8 ft. wide
Salvia Gracias aka Bees Bliss – 1 – 2′ tall x 8′ wide
Acacia ‘Low Boy’ – 1′ tall x 10′ wide
Baccharis ‘Pigeon Point’ – 1′ tall x 8′ wide
Canyon Grey Sagebrush – 2′ tall x 6′ wide
‘Yankee Point’ Ceanothus – 2 1/2′ tall x 10′ wide
Ceanothus ‘Joyce Coulter’ – 2 1/2′ tall x 10′ wide
Harmony Manzanita – 2′ tall x 6′ wide
Franciscan Manzanita – 2’-3’ tall x 6’ – 8’ wide
John Dourley Manzanita – 4’ tall x 5’- 6’ wide
Dana Point buckwheat – 3′ tall x 4′ wide
Rhus integrifolia ‘Lemonade Berry’ – 6′ high x 10′ wide
Ceanothus ‘Concha’ – grows 6 – 8′ tall x 8′ wide
Toyon ‘Christmas Berry’ – 7′ tall x 5′ wide
Drought tolerant plant choices:
Myoporum parvifolium – 8″ tall x 8′ wide
Sageleaf Rockrose – 2′ tall x 6′ wide
Prostrate Rosemary – 2′ tall x 8′ wide
Bougainvillea ‘Oo La La’ – 2′ tall x 8′ wide
Salvia leucantha ‘Santa Barbara’ – 3′ tall x 4′ wide
Lantana Radiation 4′ tall x 4′ wide
Pride of Madeira – 4′ tall x 5′ wide
Cape Plumbago 5′ tall x 6′ wide
Watering your plants on the slope can be a real problem if you don’t have your slope mulched and use sprinklers with a low precipitation rate. Regular spray nozzles apply so much water that it starts to run off the slope after a few minutes. And if you turn off the water early to prevent this runoff, you’re not watering deeply enough to have healthy plants.
MP Rotators are the best nozzles to use to water your slope if you’ve used native plants like Ceanothus, Manzanita, Buckwheat and Salvia. These nozzles have a very low precipitation rate which allows the water to soak in rather than run off.
If you’ve gone with plants from the drought tolerant list like Bougainvillea, Plumbago and Lantana, setting up a drip system will be the most efficient way to water. Circle each plant’s root zone with Netafim drip line with pressure compensating emitters and connect all these with blank tubing. That way, only the plants will be getting watered which will significantly reduce the amount of water you use and limit the weeds.
Use check valves on your piping to prevent water draining out of the lowest head when the water shuts off.
After planting, mulch the slope with a shredded mulch that won’t slide down the hill with the first heavy rain. The mulch will prevent erosion until the ground covers spread out, as well as keeping down weeds and retaining moisture.