Garden lime is a soil amendment composed of calcium carbonate or magnesium carbonate, used to elevate the soil’s pH level. When soil becomes too acidic, the availability of certain nutrients, such as phosphorus and molybdenum, decreases, hindering optimal plant growth. Applying lime neutralizes this acidity, creating a more favorable environment for many common lawn and garden plants.
Retail Stores and Garden Centers
For the average homeowner, the most convenient places to purchase garden lime are large national home improvement centers. These stores consistently stock common soil amendments throughout the growing season. The lime found here is typically offered in smaller, manageable bags, generally weighing 40 or 50 pounds, making transport and application straightforward for smaller projects.
Independent local nurseries and garden centers are another excellent option, often providing specialized advice alongside their products. While prices might be slightly higher than big-box stores, these local businesses often carry pelletized lime, which is the preferred form for home use due to its ease of spreading. The availability of smaller bags caters directly to consumers not requiring industrial volumes.
Specialized Farm and Agricultural Suppliers
When soil correction requires larger volumes, specialized suppliers are necessary. Agricultural co-ops, feed stores, and landscape supply yards cater to commercial growers and those with expansive acreage. These establishments offer significantly larger bag sizes, such as 80-pound sacks or palletized ton quantities, providing substantial cost savings through bulk pricing.
These specialized vendors are more likely to carry agricultural-grade products and powdered lime forms that are less common in general retail. For large-scale lawn renovation or treating several acres, these suppliers are the most economical and practical source for acquiring the required tonnage. They may also offer specific services like custom blending or delivery for very large orders.
Key Differences in Lime Forms
Before purchasing, buyers must distinguish between the available physical forms and chemical compositions of garden lime, as each type behaves differently in the soil. The physical form is usually either pelletized or powdered (pulverized). Pelletized lime is created by compressing fine powder into small granules, which significantly reduces dust and allows for easy, uniform application.
Physical Forms
Pelletized lime must absorb moisture to break down, meaning it acts more slowly to change the soil pH compared to its powdered counterpart. Powdered lime offers the fastest reaction time because its fine particle size maximizes surface area contact with the soil immediately upon application. While faster-acting, the dust created by powdered lime makes it messy to handle and difficult to spread evenly without specialized equipment.
Chemical Composition
The chemical composition differentiates between calcitic and dolomitic lime. Calcitic lime is composed primarily of calcium carbonate, supplying calcium to the soil to correct acidity. Dolomitic lime contains both calcium carbonate and magnesium carbonate, supplying both calcium and magnesium alongside the pH correction. The choice between the two should be based directly on the results of a soil test, which indicates existing magnesium levels. Using dolomitic lime when magnesium is already adequate can lead to a nutrient imbalance, potentially causing deficiencies in other elements.
Calculating How Much to Purchase
Determining the exact amount of garden lime required begins with accurate data from a professional soil test. This test provides a specific recommendation, typically expressed as pounds of lime needed per 1,000 square feet to reach the target pH level. This precise measurement allows for the most efficient use of the product, preventing both under-application and costly over-application that could harm plants.
To calculate the purchase volume, measure the total area to be treated. For example, if the test recommends 50 pounds per 1,000 square feet for a 5,000 square foot area, the total need is 250 pounds of lime, which converts to five 50-pound bags.
If a soil test is not available, a general maintenance application can be performed, though this carries a risk of misapplication. A common maintenance rate for established lawns is 25 to 50 pounds of pelletized lime per 1,000 square feet every one to two years. This guideline should only be used for slight pH adjustments and not for major soil correction projects.