Question From: San Ramon, California, United States
Q: Helping a friend choose a ground over to trail over 2 existing retaining walls about 4' tall. One is 30' wide, 5.5' deep; the other is 25' wide, 5.5' deep. Unimproved soil, clay based. Minimal watering system in place. Retaining walls edge large pool. I'm thinking one of the cotoneasters, but which one, and how many? My friend really wants something that will look graceful and be evergreen. Sunset zones 16-17, USDA zone 9b. Will cover ground w/3" of redwood mulch after planting.
A: Elana, I live in Michigan and am not familiar with your growing conditions or plants that do best in Califormia. I recommend your friend contact a professional for help. Good independent garden centers often have landscape services and may offer them for free when folks buy plants. An onsite inspection would be a good idea as your friend has several issues including exposure, soil and drainage as well as irrigation. Water restrictions may be an issue and should be considered when choosing plants. Best And Happy Yardening, Nancy