Soil Texture & Structure: Test Will Show Structure of Garden Soil

In general, trees, shrubs, vines and perennials, etc. are very adaptable. They grow well in most soils if they’re given proper care. However, you’ll be far ahead of the game if you know what type of soil you have. You will simply be reassured that your type of soil falls into a large middle range that provides a healthy environment for your plants.

If your soil happens to fall into an extreme at either end of that range, you’ll be able to select plants that are particularly adaptable to that type of soil or try to determine what can be done to improve your soil. Every soil has depth, fertility, texture (relative proportions of sand, silt, and clay), and structure (the amount of air space between these particles to provide good drainage and water retention and the way these particles are put together). In addition, it has an acceptable acid/alkaline balance conducive to the healthy growth of most plants.

How to test your garden soil

The most accurate way to find out what kind of soil you have, is to take samples to a soil laboratory.

You can also do a simple test yourself to get an idea of your soil’s structure. Fill a quart jar about two-thirds full of water. Add soil until the jar is almost full. Add one tablespoon of Calgon to help the particles settle (this is optional). Screw the lid on, shake vigorously, set it down and watch the particles settle.

In a short time the heaviest particles (sand) will sink to the bottom, making the sand layer visible. The next layers will take a little longer to settle because they are so small in comparison to sand particles, so get back out in the garden and finish what needs to be done.

At the end of the day you can check the jar. Keep in mind that if the water is still muddy looking, the silt and clay particles haven’t all settled to the bottom, so wait until the next day to see what layers have formed. The next layer after the sand will be silt particles. The layer after that will be clay. After all the soil particles have settled and the water is pretty clear, you will be able to tell what type of soil you have. There are so many different types of soil, but the most common ones are sandy soil – if there’s less than 5 percent clay, medium loam – 10 to 20 percent clay, clay soil – 25 to 30 percent clay, and heavy clay if there’s 35 to 50 percent clay.

Both sandy and clay soils can be dramatically improved with the addition of organic matter.

This means that if you cultivate to a depth of 8 inches, add 3 to 4 inches of organic matter over the top of the soil before you mix it in.

Remember, you can’t change your soil overnight. It takes years. So the sooner you start adding organic matter, the sooner you will improve your soil.