The long-term weather forecast is calling for a continuing string of nice days through Thanksgiving Day. Many gardeners will be able to catch up on garden projects that they may have been putting off. One of these projects that often gets overlooked is liming the garden soil.
If you have been fertilizing your garden regularly with conventional fertilizers for several years in a row, chances are your soil may need lime. November is an ideal time to apply lime.
Lime is a calcium-based soil amendment that farmers and gardeners use to raise the soil pH. Older farmers used to refer to it as “sweetening the soil.”
It’s not a good idea to just guess if your soil pH is low, soil should be tested.
To test for pH only, you can do it yourself with a pH test kit from a garden center. These kits are fairly accurate. Just make sure you buy a fresh test kit because the test-chemicals will get old over time and can produce an inaccurate reading.
Although a DYI test kit may not provide you with detailed information for liming, it will however give you a general range of your soil pH.
Soil testing labs provide the most accurate and complete results. Soils vary greatly in texture and organic matter, which affects the way lime reacts. Labs take this into account when making recommendations.
For Michigan gardeners, arrangements for a soil test can be made through local MSU Extension offices. You purchase a mailer in person from the Extension office or online through the MSU Extension Bookstore. After gathering your sample of soil, you mail it in. A soil lab tests the soil and sends the results to MSU which in turn sends you the results with recommendations. These test results include not only pH but also phosphorus, potassium and other soil characteristics.
There are several different types of lime such as ground limestone, hydrated lime, calcium carbonate, seashells and others. Each type has a different application rate.
Most lime packages have application instructions printed on them that give a good approximation of application rates. The amounts are usually given in pounds per 100 square feet or 1,000 square feet, depending on the size of the bag.
Wood ashes are also a source of calcium carbonate and can be used to raise soil pH. Because ash particles are so small, they react with the soil very quickly. It’s easy to put on too much causing a pH imbalance in the other direction. No more than 25 pounds of wood ashes per 1,000 square feet every other year is a typical application rate.
Generally speaking, sandy soils need liming more frequently than loam or clay soils, and it will take more lime to change the pH of loamy or clay soils than sandy soils.
Since liming materials don’t move through the soil very easily, they must be incorporated into the soil by tilling in order to be effective.
Applying lime or other calcium containing materials now will give them time to react with the soil before planting time next spring. Plus, the freezing and thawing of the soil that happens during winter will help distribute the material more effectively.
So, head out to the garden center, pick up some supplies and get some productive work done in your garden while the mild weather lasts.