In fact, soil will make or break your garden. Eighty percent of all plant problems in a garden can be related to the soil. Poor nutrition, wrong pH, poor aeration, poor drainage, too much drainage and others are all examples of soil problems. Great soil will allow you to increase your plant palette. Some plants can grow in more sun than recommend if the soil is ideal.
Plants can double or triple their size in the first season if soil is rich in organic matter.
To find out the status of your soil, do a soil test with your county's Agriculture Extension Service. The lab will give you recommendations for improving your soil. An ideal soil is one like pastry dough, which crumbles when you handle it. Organic matter improves your soil. You want a minimum of 5 percent organic matter in your soil, and 16-20 percent would be ideal.