Luckily, when I started to till, I noticed that there was a layer of sand underneath all the clay, so I mixed the two together.
But could my soil sustain these new plants? Like any well-meaning vegetable gardener, I wanted gloating rights at the end of the season. I envisioned (and still do) gigantic peppers, beans by the bucketful, and flourishing Asian vegetables. Better do a soil test to be sure of the soil- one that doesn't involve waiting long for results.
I filled some jars 1/3 full of soil from each of my planting areas, poured water on top of that, and shook up each jar. I let the jars sit for a few hours so the soil samples could settle into layers of silt, clay, sand and organic matter. If you like numbers, you can measure the width of the layers and calculate the percentage of each material.
Then there's the pH test, which can be useful when growing vegetables because they're less tolerant of acidic soils. I've heard that the same color-changing chemical compound in litmus paper can be found in red cabbage, so I boiled some cabbage and combined a teaspoon or so of soil from each site with the water from the cabbage. The results were a disappointing brownish-purple. Supposedly the water would range from blue to pink depending on the acidity, but I didn't get much range past murky. Maybe I used too much soil. Considering the relative convenience of litmus paper, next time I'll stick with the litmus test.
Judging by the existing materials and the acidity of the soil, I get a better idea of how much compost I should add, and if I need to add any lime to make it more alkaline. Testing the soil now will also help me diagnose any plant problems that come up over the season, because so much of plant health depends on healthy soil.
After tilling in the amendments too the soil I made a series of berms for extra drainage, planted my new vegetables and walked away with an optimistic smile.