As you prepare your garden for the growing season, don’t forget about your soil! A soil test is an easy and quick method to understand what’s going on in your soil. With this information, you can add exactly the amendments your soil needs for the health of your soil and plants. Soil testing also protects your local ecosystem. Over-fertilized soil produces runoff that harms local water systems, killing wildlife and causing damaging algae blooms.
What Is a Soil Test?
A soil test is a process of obtaining a sample and analyzing its pH level and the various elements in the soil, including phosphorous, potassium, magnesium, and calcium. Some tests include a few other nutrients and factors important to garden health. More in-depth tests are also available for cases of suspected contamination by heavy metals or other pollutants.
The Basics of Soil pH
A pH of 7.0 is neutral, while levels below that are acidic and levels above are alkaline. Soil pH influences how available the nutrients in the soil are to your plants. When the soil pH is out of the optimum range, the microorganisms in the soil that break down organic materials can become inactive, too. It’s one of the most important factors for soil fertility.
The availability of nutrients tends to be highest at around 6.5, and most plants prefer slightly acidic soil with a pH level of around 6.0-6.5. (A notable exception for the survival gardener is blueberry, which likes more acidic soils). If the soil pH is off for a particular plant, it can become stressed and become more susceptible to diseases and pests. It may grow too quickly, or not at all.
To reduce soil acidity, you can amend the soil with garden lime or limestone. It contains calcium and magnesium. Garden lime is best applied in the fall to allow soil plenty of time to adjust before the growing season. If you have alkaline soil, an amendment with sulfur (like sphagnum peat moss) can help. Compost can also improve soil acidity over time.
When to Soil Test
You can test your soil any time, but Fall is generally the best time of year. Avoid testing wet soil or recently fertilized soil. It’s better to get your test done well ahead of the growing season so that you have plenty of time to plant cover crops, add soil amendments, or make other adjustments to your soil. If you wait until Spring, you may find that you’ve got a longer wait time to get results.
The frequency of your testing depends on the state of your garden and its soil. If you’re trying to work out problems in your soil, an annual test is a good idea. In most cases, every 3 years or so should be sufficient once you’ve got a handle on your situation. Occasionally, you may decide to send in samples for problem areas of your garden to compare with the rest of your soil to help you understand if your issues are related to soil health.
How to Get a Soil Test
Local garden centers and companies offer soil testing, but your local cooperative extension is usually the best resource. Soil tests from extensions are usually free or require a small fee. You’ll get a detailed analysis of your soil, which probably will include suggested amendments to improve your soil quality. Even if you have to pay for the test, it’s worth the investment. You can be confident you’re adding the proper amendments to improve soil health rather than wasting effort and fertilizer.
Soil testing is a great idea to get a head start on the planting season. Getting a soil test is inexpensive and easy, and it takes the guesswork out of your gardening by providing you with important information about your soil fertility and health.