Before you do a ton of amending, what are your goals and plans for the area...

if you do xeriscaping, you may not need to do a lot of amending?

if you are planning some paths or patios, you won't need to amend those areas, either?

how about a very large swimming pool??

Yard pool with maybe guest house. That way people from this site could have a place to vacation when it's to cold to garden. Can I get a second on this suggestion?

Y'all bad.
Y'all very very bad.

You forgot to mention a hot tub for chilly evenings...

It sounds like you live in what a friend politely calls a "Challenging Climate" (he's from England, went into shock when he landed in Texas).

Challenging Climates call for strategy, acceptance of reality (work with what you've got, not with what you wish you had; don't even look at Himalyan blue poppies!), water conservation, & native plants.

I'd start at the County Agricultural Extension Agent's office;
they'll have data on the soil in your area (& they can do a soil test for a small fee), & they'll know what kind of landscaping is likeliest to work.

See if your city water department has some flyers or booklets on conserving water in the garden.

Check into some garden clubs, especially those that stress organics & native plants.

A bare garden slate is a wonderful thing to contemplate!

Before planting anything you should have a good idea what your present soil is and that means contacting your local office of the University of California USDA Cooperative Extension Service about having a good, reliable soil test done for a base nutrient load and soil pH level. Along with that these simple test will give you a good idea what you need to do to make what you have into a good, healthy soil that will grow strong, healthy plants;
1) Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer you soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

Along with this information you need to know where your utilities are, what hardscape (stuff not easily moved) is there, where the sun is when, traffic patterns, what you see from inside. Once that information is gathered you can then start to plan what to plant where, taking all the previous information into account.

Here is a link that might be useful: UC CES

Hi Moliemole, you seem to describe your soil as decomposing granite which means you are not down on a bajada with its deeper desert soils. Granites tend to produce acid soils, even in the low desert, and properly managed will do for gardening. Just remember, you can't garden by adhering to gospels according to Eastern Gardening Establishment. Instead, talk to locals and get one or more of desert gardening and xeriscaping books.

I don't know in what county your in; some county ag department (and US Coop Extension offices) have handouts on useful subjects like what and how to grow in your challenging environment. California gov. agencies haven't done soil testing for the public in decades, so look in your local yellow pages for one near you. Also ask local farmers/orchardist, if any, about such resources.

Soils will not be as important as microclimate. You can amend the heck out of a bed and plant beautiful annuals and perennials and have them devastated in a day or two from high, hot and dry desert winds sandblasting your plants. So figure out niche gardens perhaps with natural wind breaks for some planting and mid-day shade for other plants. Desert peoples have farmed in harsh climates, so emulate them. Often they plant in natural or made depressions.

Be creative and make interesting gardens.!

how about not dealing with the soil that is there for now and consider using raised or lasagne beds that get the gardening started easily.

where you want to grow lawn eventually i'd simply mulch the area and let that get worked into the soil by the worms etc, or y could buy a load of good top soil lay that then lay the lawn.

some pics on how we do our gardens on our site might give some ideas?

len

Here is a link that might be useful: len's garden page

What jumps to mind is the book "Gaia's Garden", which has a story about making a permaculture garden in the desert. Worth reading for any gardener, but might give you some ideas.

-L

Thanks for all the great info... We are in the process of having some hardscape installed and I will then get to work on the gardening part. The dirt clumps well, smells earthy/sandy, great drainage -- I heard one of the contractors say its mostly decomposing granite...I will definitely look into soil testing. I didn't see any worms in my shovelful but I know that they exists -- with the recent rains, I found a bunch of them dying in our driveway. I really think I need to look into permaculture and trying to keep as many native plants as possible (which will be tough because I so love a full lush garden). I have to be careful about the hot summers and cold winters -- not snowy but it definitely freezes.

Y'all who are voting "pool" must have been talking to my husband! He's still campaigning for a hot tube and fire pit :)

It is important for a gardener to know what they have for soil because not all plants want, or need, a really rich soil. Most all herbs will not develop the flavors we want if grown in even average soil because the developed eons ago growing in very lean and mean soils.

I'm trying to picture how a soil can be both hard AND sandy at the same time. Do you have any neighbors or local nurseries who might be able to provide advice about the soil and what will grow on it? What kind of landscaping do you see in the area? Ultimately it will probably end up as a compromise between what you want to grow, and what you CAN grow.

You can still have a full and lush garden, but you probably realize that it will be both labor and water intensive. Why not establish a small garden near the house where you will see it frequently and will also be able to cultivate and water it regularly? Perhaps a rain barrel could help provide water for it? This could be a little oasis with the rest of your property dedicated to native and/or xerophytic plants that can take the native conditions with much less care or water.