The soil should be uniform in its texture, not in two different layers. And sand is not very helpful in amending clay soils - you need a great deal of it (at least 50% of the volume) and it needs to be very coarsely textured to be effective. Otherwise you just end up with something like adobe..

Although difficult to do now with plantings in place, adding organic matter (like compost) is the best way to lighten and loosen clay soils. You are currently encountering drainage issues - sand drains too fast and clay too slow - and there is not enough depth for the plant roots in the sand before they encounter the harder to penetrate clay layer.

Well if compost can improve the soil will compost tea also improve it or does it just give the nutrients to the plant

Compost and compost tea are two very different things and compost tea will not do much to improve any soil that needs organic matter.

To begin to make the soil better you need to take a good look at it.

How much organic matter is in that soil?

How well does that soil drain?

How well does that soil retain moisture.

How much life is in that soil? How many earthworms?

What does that soil smell like?

Perhaps these simple soil tests may be of some help,

1) Soil test for organic
material. 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.
For example, 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 your soil will smell, to a point. Too much organic matter
can be bad as well.

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.

In addition a good reliable soil test, your Texas A & M Cooperative Extension Service will do this, for soil pH and nutrient levels would be a good idea.

Thx for info I can tell you I haven't seen an earthworm since I moved here in August. As for the drainage test we have had over 10 inches of rain in the last w weeks and it has rained everyday at least for a short period of time 1t to 30 minutes with some heavy rain and have seen standing water still 12 to wrong hours later the next day. But I will look at the other factors. I do know I will have to add compost to soil. Again thx for input.

Wayne, define what you mean by "native topsoil". Is this "topsoil" more of what this garden already has? What benefit will more of the mineral portion of soil have in this garden that needs more organic matter?

Digging a hole through a couple of hundred feet of clay may not be very feasible, but over tine organic matter will open up that clay and help0 the drainage.

kimmq is kimmsr

native topsoil...let us contemplate the meaning of words.

topsoil...the top layer of earth in any given location. It is not a carefully blended formula of prescribed components, it is...let us see what words were already used and what possible meaning we may parse from those words...what exists in the top layer of soil in any given location.

native...what is already there. Not purchased, not blended, just what was already there.

kimmq is kimmsr, really, drilling a hole several hundred feet deep may not be feasible? First, I never said it had to be deep...it just has to break through the layer that is preventing (slowing, in this case drastically) the movement of water through the layers. Second, given your apparently vast knowledge of soils and...well, everything growing, you should know this...if you live in certain parts of the southwest, parts of Texas specifically, there is a layer called caliche. If you hit this layer, digging a hole six inches deep becomes a matter to involve high explosives.

There may be no need to dig an extensively deep hole. Soil is comprised of a series of layers, and some of the layers may be several feet thick, or they may be a minute fraction of an inch. If you have a layer of dense clay, there may very well be more permeable material beneath it...and unless you have x-ray vision, you'll never know. Two feet may be sufficient.

The problem is excess water. Raise the bed, providing dry feet to young plants, or drain the water. This can be done laterally or vertically. There is a third possible solution, which is, does this garden have to be in this location. But that's another can of worms, and I will leave that question to the people who actually have to live and garden in a certain area.

First of all soils differ. Oftentimes people say they have clay soil or a layer of clay like the op. How much clay is left to a guess here. Probably no soil is totally clay. I suggest that the op get a heavy duty potato fork and mix the 2 layers and add organic matter so that 10 inches is uniform. Probably a deep tilling is necessary to mix the soils fully.

Mixing coarse/medium sand into somewhat clayey soil along with organic matter like rotted horse manure with hay in it and peat moss and leaf compost works extremely well for me...superb soil. Yours may be some different. Mine is silty clay loam and clay loam.....these contain clay, sand, and silt already so mine only needed 3 inches of sand added.

Neither of those answers the question, What is "topsoil?"

"Topsoil" is simply the top 4 to 6 inches of soil from someplace. It may be something worth paying for or it may not be worth a penny. It will be about 95 percent mineral and 5 percent organic matter at best.

So why tell people to add to their soil what they already have, the mineral component, when what they need is organic matter?

kimmq is kimmsr

Kimm, Adding texture minerals to change the structure can be rewarding. It certainly has been for me. Certainly, adding organic matter is very rewarding too. It isn't always a one way street.

Sometimes adding the mineral portion of soil to the mineral portion of soil might be of some help, but unless one adds a very large amount of, say, sand to clay it will do little. Most every soil scientist I have read in the last 50 years has said that to make much difference in clay soils by adding sand you would need to add at least 45 percent sand by volume, a lot of sand, some state you would need as much as 75 percent sand.

Conversations with many people over the years has taught me that most people think "topsoil" is loam and it is not. Many people also seem to think that "topsoil" is some kind of magic elixir and it is not. "Topsoil" in most instances is not the solution to any soil problem unless that "topsoil" is loam and is applied quite thickly, 4 to 6 inches of loam in most instances will not be enough, and that would certainly be true of "topsoil".

Perhaps this article will be of some help.

http://www.ncagr.gov/agronomi/pdffiles/sfn14.pdf

kimmq is kimmsr