You'll have poor drainage with clay soil. Its tiny particles bind together when wet and keep water from draining properly. Plants in clay get too much water and too little air to thrive, and their roots have trouble penetrating the soil. Organic amendments will improve clay soils. Sandy soils consist of larger particles, which create a porous mix and allow water to drain through too quickly.
Plants rooted in it have trouble absorbing water.
Organic amendments will also help with this type of soil. The ideal growth soil is a combination of large and small particles known as loam . It holds water long enough for thirsty plants while safely draining away the excess. It's best to have your soil tested before you start planting to see what nutrients it might be lacking. You should be able to find labs in your area to do a test for a nominal fee.