soil questions

[A Cut Above]

I have about 6"-10" of clay soil around the house that is over the top of sand and a weak sand stone. The clay is rock-like when it is dry. What should I do to improve my growing conditions? I also have several clumps of oaks with 4-5 trunks coming out of the ground in one relatively small area (they are all too deep). This creates a shade problem also. One last question, is clay soil alkaline or acidic? Thanks for any help.

[Nadine]

Get your soil samples off to Texas Soil Lab (see the business directory). Adding humate or a good quality compost will help immensely. Raking half an inch of compost over the grass will save you a lot of money on your water bill, too!

You need to get the root flares exposed on those trees!

Shade is a problem if you want grass to grow over the entire lawn. Would you rather have trees or grass? If trees could choose, it would be just mulch on the ground around them.

[Dchall_San_Antonio]

St Augustine grass will usually grow under trees if the canopy is raised up high.

Clay can be either acidic or alkaline depending on the make up of the clay. I improved my clay by slowing watering it for a week. I stretched out a black plastic soaker hose and turned it on to a trickle for a week. At the end of the week the soil was very soft and absorbent. That was several years ago and the soil remains absorbent like a sponge. It is soft when wet and very hard when dry, exactly like a sponge.

[Kathe Kitchens]

As any soil scientist will tell you, clay soil that dries out like a hard sponge is lacking in organic material. Adding compost and cornmeal will change its consistency to more like that of a chocolate cake, and it may still dry hard but not into a solid, concrete condition except in extreme conditions. It's a matter of mixture. The proper ratio of organic material in soil is mandatory to its life sustaining ability. Malcolm Beck and Howard Garrett have preached this for decades because it is the simple truth. A desert lacks in lush growth. A forest does not. The difference is the organic matter available in the soil.

The best way to teach yourself the difference is to do the experiment yourself. Select an area and add compost, and after two weeks to a month, compare it to the area where no compost was added. And I'm not talking about a long project rototilling it into the soil, etc. I'm talking about simply spreading an inch or two on top of the soil and watering it in. If you work it into the soil so much the better, but it isn't mandatory because the natural process will make it happen anyway.
Kathe :D