Dolomite Lime, Natural
(This product is a candidate for organic certification. To ensure the lowest price, KBS has chosen not to register this product.)
Add to acidic soils to increase pH. A source of magnesium.
Dolomitic lime is a rock. It is calcium magnesium carbonate, CaMg(CO3)2. It has about 50% calcium carbonate and 40% magnesium carbonate, giving approximately 22% calcium and at least 11% magnesium.
When you buy it for your garden, it has been ground into granules that can be course or very fine, or it could be turned into a prill.
Why Use Dolomite
Dolomite is best used to change the acidity, or pH, of the soil. Start with a soil pH test, which you can buy at garden centers, to determine the existing pH. Most plants do best with a pH of 6.0 to 7.4. If your soil registers with a pH of 5.9 or below, dolomitic lime can help raise the pH to make the soil more plant-friendly. Some plants prefer acidic soils, where the pH is lower, so check on your specific plants’ needs before adding the dolomite. Some plants, especially vegetables that have lots of seeds inside, such as tomatoes (Lycopersicon esculentum), need extra calcium as they grow, and the dolomite is an excellent way to provide that nutrient.
When to Use It
You can add dolomite to your yard, flower beds and vegetable gardens any time there’s no frost or freezing temperatures, but it’s best to add it in spring or fall. Pick a day when no rain is predicted so it won’t wash off the soil before being absorbed. With vegetables, adding the dolomite before you plant gives the seeds an extra boost, then you can add more as necessary as the plants are growing
How to Apply
If you’re adding it to an empty garden where you plan to plant flowers or vegetables, turn it into the top 6 inches of the soil before you plant. To change the soil’s pH, determine how much you need and spread it on top of the soil. For example, if your soil has a pH of 5.5 and you want to raise it to closer to 6.5, add 10 pounds of dolomite per 100 square feet of space — that would be equivalent to a 10-by-10-foot bed or a 5-by-20-foot bed. To prevent burning existing plants, spread the applications out throughout the growing season.