I live on a hillside in the San Francisco Bay Area with superb drainage. Behind my property is several hundered yards of open space preserve, ending in a ridge where there are other houses. Most of the hillside is covered with scrub brush and poison oak. It has full sun for virtually the entire day. I would like to plant a few conifers in various spots on the hillside and have begun clearing paths through the poison oak etc. in order to have access so that I can plant the trees. Ideally, I would like to choose trees that will do the following: (1) Help kill off wide swaths of the poison oak, etc. over time (2) Create wildlife habitat (3) Grow quickly I am fine with having to go up the hill a couple times a week to water them over the first year or so. Any thoughts on what trees would be good choices for such a situation?
Same ones used in Golden Gate Park: Monterey cypress, Bishop pine, maybe other coastal native species. Visit the Strybing Arboretum (where you will find signs and labels telling what trees are) and look at the big, old conifers there. Some years ago there began to be a problem with some of these aging and blowing over, readmitting the wind and sand. But you are probably not planting for 100 years. It also sounds like your site is less severe.
Poison-oak is really good wildlife habitat! (local native species, produces berries that birds like, etc) Definitely avoid Eucalyptus - that creates a wildlife desert (unless you're in Australia, of course) As well as the ones Ron mentions, also try Tanoak, Coast Live Oak, Madrone, Umbellularia.
Quick growth - you might want to differentiate between upright and wide growth, as you want to suppress the growth of other stuff. The tall trees will take some time to acquire significant spread. Maybe some interim plantings of spreading junipers would be in order - though I should add that I'm not sure there is much wildlife habitat under junipers.
Hi, Junipers can be great for wildlife. They produce berry like cones and the dense, shrub forming varieties can be good as nesting habitat. Many are more than happy in very dry, well drained soil and in full sun. There are loads of fantastic Pines that can be used too. The ones mentioned above are perfect but there are some pretty unusual ones you may wish to try too. Pinus patula, Pinus mugo, Pinus palustris and Pinus pinea should all be ok in your area. Then there is the Cupressus genus. There are some pretty good species for hot and dry conditions and some of the cultivated forms are superb. Cupressus macrocarpa Saligna Aurea is one of my favourites, just for being different. Not sure how attractive it will be to wildlife though. How about checking out the Podocarpus genus too? Some of the species from New Zealand and South Africa may be ok with you. Luke
Thanks for all the input. I think my favorite is the Monterrey Cypress, which grow quite large around here. I've heard from other sources that they can grow pretty fast too. I think I'll plan to get a couple of those in the ground this fall. Regarding Poison Oak. I consider Poison oak my mortal enemy. It may be good for wildlife habitat, but it must die. I am constantly battling the stuff and I am highly allergic. The juniper idea is interesting -- maybe I'll plant a couple of those and see what happens?
Make sure you get California Juniper (Juniperus californica), that's the only native juniper in the SF area.
You mention allergies and I understand that Junipers can cause severe allergies. Something more perhaps to consider.