Update (2013 follow-up) of successful steep slope plantings on a dry sandy slope in So. Calif. In my previous post, I listed drought-tolerant Calif. natives used in my initial plantings. But the fire department does NOT like summer-deciduous plants such as sages. And as water was reduced, plants such as Wooly Blue Curls did not survive. It has been a 10-year project and this is how I turned a steep dry sandy slope into a drought-tolerant garden: 1) Basic Calif-native trees & shrubs were planted (a couple of Coast Live Oaks, lots of fire-resistant Toyons, McMinn Manzanitas, Sunset Manzanitas and the wonderful Hollyleaf Cherry are good choices). At the driest upper areas, Palo Verde Trees were planted for their deep tap roots and provide 25% shade cover when leafed out during the summer. 2) The slope is very steep. As I worked the sloped while planting and watering, a curvy informal foot trail started to form. As the trees and shrubs took hold of the soil, these foot trails were gradually deepened. Most native ground covers are sold as tiny little things that can't get a hold on steep slopes or are buried under a shovel of dirt unless planted at the base of an agave for protection. Tip: Buckwheat prostrate is a great steep-slope ground-cover that drapes down and hides the vertical cut edge of pathways. 3) The native flower shrubs (Wooly Blue Curls) died. Calif. Fushia is very dought resistant and is best if tucked under an agave to brighten up the driest desert plantings at the upper level. As the trees, shrubs and trails became established, lots of agaves were added to hold the surface soil. Cabbage-sized boulders were often used to hold new plants into the slope. 4) Erosion: A line of three monster Blue Agaves were planted in a horizontal line whenever a "dam" was needed to divert rainwater from running straight down the slope. The maturing slope contours (trails) were gradually deepened and dirt bermed up so that rainwater would travel across the slope and flow into collection basins behind trees and shrubs along the way. The pathway/contours took a lot of time to evolve but was well worth the effort. Instead of walking "on" the slope, the deepened pathways amongst the plantings now gives the feeling of a nature hike. 5) Gradually, non-native plants (aloes) were added to the semi-shaded areas. For the upper "desert" area, tons of barrel cactus and agaves were used as a ground cover alongside uprights such as pony-tail palms and colorful upright non-native Sticks on Fire & Crown of Thorns. This large (1/2 acre) hot dry, sandy steep slope was a real challenge and still is not finished. To make things look right on a large steep slope, you will need dozens of each plant to form groupings. You can use dozens of spikey Agave Geminiflora to give the illusion of a "meadow". Dozens of Golden Barrel cactus planted in an informal "swirl" along a switchback gives the impression of a flower garden from a distance. With a little imagination and a lot work, a steep slope can become a beautiful garden. Take courage, though, because it takes YEARS before others are able to "see" what you have planted. And on difficult slopes, it is better to overplant your basics of trees & shrubs because on a contoured steep slope, a sprinkler grid is too complex and you will lose some trees/shrubs when hand-watering is reduced.

Just wondering if any of the Australian natives would be useful. They have to put up with browsers so they often have their own inbuilt 'repellents'. Agonis. Banksia. Callistemon. Melaleuca. Hakea (watch out for this one as it may be a pest species in volcanic soils.) Hovea. If your soil isn't too lush then something like Protea or Greyia or Leucadendron (South African) could be useful. Cordyline australis could also be useful, It's usually the 'last tree left standing in the paddock' and will definitely tolerate wind.

GGG - I think I have mentioned this before, but how about mahonia? It is seriously deadly when it comes to sharp leaf tips. I planted some along a wall so that our kids won't be tempted to use the wall as a jumping off entertainment place. It works! I have been stuck so good that I bled and bled. Hurts! If someone tried to go through a closely planted bunch of mahonia, they would regret it. You could plant them in two rows, alternating placement, so they would form a dense barrier. The flowers smell lovely in late winter, and the berries are - I think - edible! Many species of birds love the berries too, so that is fun, if you like to watch birds. I got a bunch of mahonia from a friend - dug up some pretty mature ones, and they all survived. I also think they have a very interesting sculptural quality, depending on how you let them grow -- whether you do or don't choose to prune them. From what I can tell, they grow very well down here -- so that might be a good choice. Good luck!

Yes I love them too, as do the birds. The previous owners built the house and were keen to leave us with photos of the new gardens. We have 3 huge red callistemons at the front which show up in their photos as tube stocks....basically sticks in the ground. They are huge and very healthy now so I am guessing they would be about 25 years old. Just pray that the wind doesn't blow in the direction of your swimming pool too often!!!! Grr its a real pest in that manner.