Soil Test How-to

Plants need a lot of nutrients to grow, but the three major elements they require include nitrogen (N), phosphorus (P) and potassium (K). (Note: Fertilizer package labels usually have three prominent numbers listed: the first number is for nitrogen, the middle for phosphorus and the last for potassium.) Most soil test kits (figure A), which can be purchased from a garden center, measure these three elements. Some kits also measure the soil's pH, which is important because certain plants like the pH at a certain level in order to grow properly.

Your soil test is only as good as your sample. The best time to conduct a test is in the fall and spring. Don't mix soils from several different beds. Take soil from the vegetable garden for one test, from the lawn for a second test, from the flower beds for a third test, and so on. To take samples from different locations in the garden, scoop soil by digging down no deeper than six inches (figure C). Add the soil to a bag. Once you've collected your sample, label the bag and mail it to the test provider.

• Nitrogen is important for growth as it promotes foliage development. You can get it in different sources, like grass clippings, alfalfa mulch and even granular form (purchase one at the garden center where the first number on the label is higher than the other two numbers).

• If your soil needs phosphorus, then look for a bag with a high middle number. Phosphorus is important in root production.

• For potassium, it's the third number that needs to be higher. It's vital for flower production and reproduction. You can buy potash in a bag or just use fireplace ashes.

• If your pH has a high alkaline level, use sulfur to make it more acidic. However if your pH is low and too acidic, then you can sweeten the soil by adding lime.

• No matter the amendments you make to your soil, the process is the same. Spread out the recommended amount onto the soil, then just fire up the tiller and mix it down about six to eight inches.

No Test? Try This!

If you can't test your soil, you can still amend it. Add compost, peat moss and cow manure to the soil in spring and fall. These magic ingredients will help make any soil better.