Small Tree or Large Bush on a Slope
Question from Bonnie:
I am new at planting so I will apologize if I use the wrong terminology. I have a slope that is 25ft high, 80ft wide and slopes upward at about a 45 to 50 degree angle. Very difficult to walk on and I bring the dirt down when I have to go on the slope. Live in Santee (San Diego) that is zone 9. I have planted yellow lantana-which froze and I had to cut off all of the dead branches but they are coming back-didn’t like going up on the slope to do that because I am constantly slipping. I will be planting salvia, grevillea, penstemons and yankee point. From research I need an accent big bush or small tree. I can’t find one that meets my needs.
Question 1: Do you know of a 6-8 foot tree/bush that is drought tolerant, no pruning, no deadheading, doesn’t look too bad when dormant. Basically no maintenance because they will go on top of the slope and maybe one on the bottom corner.
Question 2: Do you have a list of zone 9 plants that will go good on slopes that require no care except watering so I don’t have to go on the slope?
Answer from Pat:
Depending on where you live in Santee, you live in Sunset Zone 23 or Zone 21. Sunset Zones are far more useful here than the USDA zones that do not guide us appropriately for the plants that grow here. For example if you followed the USDA zones for plant choice you would think you could grow fuchsias in Phoenix, Arizona, which is ridiculous. Here in the west we have a varied landscape of plains, interior valleys, coastal and inland mountains, all of which combined with the greater or smaller influence of the ocean create many variations in climate. Thus a system of many zones works far better for us.
I have a similar slope in my garden and have made a sloping path on it and installed steps that go up it at an angle so I don’t slip down as you describe. But of course this takes some time, planning and materials to accomplish and actually I am no longer strong enough to do such work myself. Many people in San Diego have similar banks. I recently visited an extensive and steep bank with my garden club and the owner had created a virtual paradise on it with paths, steps and terraces for flowers, vegetables, succulents, ground covers and fruit trees—even places to sit, so it can be done. Perhaps eventually you might get hooked on gardening and then might enjoy developing that part of your property in this way. I understand that right now you just want to get the bank planted and you are looking for a tree or trees or large shrub that requires nothing but water. How about Bottle brush? I suggest Callistemen ‘Splendens’. You will get color year round with waves of red blooms that cover the plant. No need to deadhead. Flowers bring hummingbirds. Why don’t you also plant some plumbago ‘Royal Cape’ or P. ‘Imperial Blue’ . These are easy plants for banks with no care or pruning. Euryops is nice too since it blooms with yellow daisies all winter but you might feel you need to deadhead after bloom by shearing. Maybe put these down low so you can reach them. Salvias need pruning to cut off branches that have bloomed, but grevilleas don’t.
About ten years ago I wrote a book of lists with 2,500 photos in it, many of which I took, called “The American Horticultural Society Southwest SmartGarden Regional Guide” published by DK. Unfortunately, DK edited out my style and also put the name of one of their editors, Rita Pelczar, ahead of mine on the author page. Since no one knew I wrote it, it went out of print. Rita is evidently a nice person. I heard she felt terrible that DK gave the credit for the book to her instead of to me when I had knocked myself out writing that book for them. You can still find it online. Sunset Western Garden Book also has lists. Look for it online and buy the old edition with a pink flower on the cover. It has a lot more plants in it than the new one.
Good luck with gardening. One tip: you can find pellets of slow release fertilizer to stick down in the bottom of the planting hole. It really is better to plant in fall than in spring but with tropicals they do okay now—not natives, though. ‘Yankee Point’ might die if you plant now.