Despite appearances, not all soils are the same. Even within a few city blocks, dramatic differences can exist.

The best way to know what is going on in the soil is through soil testing. A soil test can determine the right types of amendments are needed in the right amount and in the right places. There are a few basic tests that can be completed depending on the site:

Physical analysis. This determines the amount of sand, silt and clay present and which amendments are required to improve soil texture. It also is a predictor of internal water movement, which is critical, as improper drainage is a leading cause of plant loss.

Standard soil audit. This test determines the nutrient levels of the soil and which are actually available for plant use. It helps determine what needs to be done to correct problems before they occur and what needs to be done to maintain healthy soil after planting.

Saturated soil analysis. This test focuses on what is at the root zone today and is important in areas that are not responding to current fertilizing practices, have had compost or other organic materials incorporated or that are sandy soils and are not holding nutrients.

If you are baffled by recurring planting problems, consult a professional horticulturist.

Source: Chicago Tribune