What can I do to improve southern California clay soil?

Answer 1

Gypsum Helps Recondition Clay And Hardpan Type Soils
http://www.humeseeds.com/gypsum.htm
Are clay or hardpan problems in your garden? Gypsum may be just the answer to help break -up and loosen the soil structure. It's not a miracle and it doesn't work over-night, but a three-year program of yearly applications should help improve poor soil conditions. It's easy to apply and relatively inexpensive for the job it does.
TO HASTEN THE ACTION OF THE GYPSUM
add compost, manure , topsoil , sand and granular garden lime.

Answer 2

One of the biggest problems with clay soils is the soil pore structure. The best garden soils are usually considered to be loams, a mixture of sand, silt and clay that provides good drainage and oxygenation, but also holds water and nutrients.

In pure clays the soil particles are very small and fit tightly together. There are few of the larger pores which allow water to drain properly and air to move into the soil. As a result, clay soils tend to be heavy, poorly drained, and low in available oxygen for plant roots. Depending on your circumstances, if you dig down in clay soils you may find a saturated layer quite close to the surface.

An excellent structural addition to clay soil is compost and/or humus. Incorporating compost into clay soils, rather than just using it as a surface mulch, aids in loosening up the soil, improving air and water flow. Some gardeners try to recreate loam-like conditions with the addition of sand (the larger sand particles create large, water-draining pores).

You can also move water out of heavy soils with drain systems, but these can be expensive and difficult to install. You can also used raised beds to avoid dealing with the underlying clay.

As far as the nutrients in your soil, if you have a test done by a laboratory you will know exactly what nutrients are missing or excessive, and the basic growing environment (eg, acid or low in organics). Most labs give you guidance on what fertilizers/amendments to use and when. Collecting the samples is easy. I have used the Univ. of Mass. soil lab several, and they do a fine job for about $13 a sample.

Remember that clay soils are especially vulnerable to compaction by foot and vehicle trafffic. Once the clay particles are pressed tightly together, the soil structure is damaged, and the fertility of the soil decreases substantially. Try to avoid this whenever possible.

Good luck!

Answer 3

Add organic matter, I mixed in compost, some sawdust,
a little sand and some steer manure to the soil in my
vegetable garden area- it was pretty bad when I first
started, now its draining much better and is more
dirt-like than clay...plus I have tons of earthworms
in there now. It took a couple of years or working
compost etc in, but the garden is going great now.

Answer 4

clay soil is compact. no air or water will penatrate it, tha goes for the plants you plant there too (including grass) it will not be able to retreave water or nutrients in order to survive. I would suggest escavating and replacing the soil will sandy loam.

Answer 5

dig up as much as you can and replace with or add lots of organic matter, sand, compost, peat moss, manure and so on.

if the area in question is large, aerate it as deeply as possible and top dress with sand to assist the drainage.

Answer 6

Don't put alot of water in it.