yukkuri kame wrote:Wild mustard grows abundantly on that hillside wherever there is open soil... it seems to seed itself vigorously
Understatement of the thread
. Benjamin most of San Diego is fairly well draining but we certainly do have our clay areas. I help take care of the orchard at my school in Oceanside and the soil is called "Diablo Clay," it is the heaviest clay I've ever seen around town. In Encinitas where I live the parent material is largely sandstone which has its own challenges. when I moved here to this house my back yard had just a few inches of mediocre topsoil before it became sandstone requiring a mattock. Even when broken up the soil has terrible fertility and holds water like a colander. Talk about needing organic matter.
J.C. there are a lot of people with horses around here so horse manure is abundant to the point of being free. I'm not sure if it's too much of a drive for you but in Escondido there is a button mushroom farm called Mountain Medow Mushrooms and they make their spent mushroom compost available for free if you load and haul it yourself. This past winter my brother and I made two bed that are part terrace, part raised bed in the hillside in our back yard. We had to dig down to break up the sandstone I mentioned so it wasn't much more work to throw some wood down in the bottom in the process. The beds were nothing special, several inches of branches and twigs from our property (not as broken down as I would have liked), several more inches of semi-decomposed compost from our pile, and finally several more inches of the mushroom compost from their farm. I set up drip irrigation on them and had the best crop of tomatoes ever! I live with my family and the 4 of us combined with our 4 closest neighboring houses haven't been able to keep up with all of the tomatoes we're growing.
Anyway I was born and raised here so it's always fun to ramble about local gardening. Best of luck with your property!