As the saying goes, “To know where you are going, you first have to know where you are.” Thus, when changing the pH of soil, the first thing you need to do is test your soil. Test it at home using a do-it-yourself kit or with a portable soil probe/pH meter. You can also send a sample to a lab for a more in-depth analysis. Sending your sample away to a private lab will give you the most complete analysis, although it’s more expensive than sending it to your local extension service.
“The soil is not, as many suppose, a dead, inert substance. It is very much alive and dynamic. ” — J.I. Rodale, “Pay Dirt” (1898-1971)
Soil can be brought back into balance fairly quickly if they are not too far out of the ideal pH range of 6.5 to 7.0. You can make adjustments by applying soil amendments such as dolomite limestone or gypsum. The best way to make pH adjustments is to incorporate compost and mulch. There are dozens of materials that you can compost. Adding organic matter to the soil also tends to make both acid and alkaline soils more neutral. On the other hand, applying chemical fertilizers makes soil more acidic.
To RAISE the soil pH
(Translation: If you have acidic soil)
If your soil is too acid, you need to add alkaline material. The most common “liming” material is ground limestone. Ground limestone breaks down slowly, but it does not burn plants like “quick lime” does. Apply it to the garden and lawn in the fall to allow time for it to act on soil pH before the next growing season. A rule of thumb for slightly acid soils: apply 5 pounds of lime per 100 square feet (say a 5 x 20-foot raised bed) to raise the pH by one point.
Apply limestone: 5 pounds per 100 square feet
Applying wood ashes also will raise soil pH. Wood ashes contain up to 70 percent calcium carbonate, as well as potassium, phosphorus, and many trace elements. Because it is powdery, wood ash is a fast-acting liming material. Be careful, a little goes a long way. Limit your application to 2 pounds per 100 square feet and only apply it every other year in a particular area.
To LOWER the soil pH
(Translation: If your soil is too alkaline)
In this case, you need to add a source of acid. Options include pine needles, shredded leaves, sulfur, sawdust and peat moss. Pine needles are a good source of acid and mulch. Peat moss with a pH of 3.0 is often recommended as a soil additive. Before you use it though, consider the other options, because peat moss is nutrient-poor, expensive, and it’s a nonrenewable resource.
So the next time you jump in a pool or sip on a glass of wine, you can relax, knowing that all things are connected — many of them by pH!!!