Dolomite is a limestone compound that contains calcium and magnesium. The best mixtures contain 8% to 12% magnesium and 18% to 23% calcium. These elements help influence the pH of the soil and provide valuable nutrients to plants. Dolomite can often contain sodium, but it should only be 2% sodium or less. More sodium can change the salinity of your soil, which can kill many plants.
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, dolomite 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, which have many seeds inside, such as tomatoes, 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 while the plants are growing.
How to Apply Dolomite
If you're adding dolomite 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.
Buy Dolomite Lime as low as $0.90 per pound including "Free Shipping" from Greenway Biotech, Inc..