Whether you started growing food at home for the first time this year or you’re a long time gardener, fall is the best time to test your soil’s pH. Soil pH is significant because it determines the availability of all the important plant nutrients.
New England soil is slightly acidic, which is helpful since most vegetables prefer a pH of 6.5 – 6.8, but over time it may become too acidic. Lime (made from ground limestone rock) is applied in order to raise the pH if it becomes too acidic. The micronutrients in acidic soil are more soluble in water, making them more available to plants (which is a good thing), but micronutrients such as aluminum, iron and magnesium may be so soluble that they reach toxic levels in very acidic soil. Getting a soil test this time of year will help determine how much lime to apply in order to obtain or maintain the desired pH for whatever you’d like to plant next season. When lime is applied in the fall, it has time to react with your soil and improve it in time for a spring planting.
There are plenty of soil tests you can purchase for your home gardens if all you are testing is pH. I have never used any of them, but I always recommend reading reviews before purchasing. At the farm, we send our soil samples to a lab at UMass that tests the pH, levels of other important nutrients and organic matter. The lab also provides suggestions on how to improve the soil depending on what we plan to grow next season.
In order to prepare a soil sample, we will collect thin slices of soil representing the top 6″-8″ of soil from multiple sections of our fields. Since some of our fields aren’t uniform due to uneven topography, wet and dry areas, and differences in fertilizer application, we will send separate samples from several places in case each section needs different treatments. We will take about a cup of soil, dry it at room temperature and then seal and label it in a bag to send to the lab.
As you ready your gardens to rest for the winter, I hope you’ll consider testing your soil to see what it might need. It can make a huge difference!
Until next time,