Uses for Lime in the Garden & How to Apply

Agricultural lime (garden lime) helps reduce soil acidity (makes the soil less sour). This makes it easier for many plants to absorb nutrients and grow well.

However, there are many other uses for lime in the garden. Below, you will learn about what garden lime does for the soil and how to use it in the garden.

Benefits of Garden Lime

Below are some benefits of adding ag lime to the soil.

1. Helps Improve Soil Activity

Using garden lime has many benefits for the soil. It encourages earthworms and beneficial microorganisms, helping keep the soil healthy.

When soil is very acidic, fewer earthworms and helpful microbes can live and work well in it. By reducing soil acidity, garden lime creates a better home for helpful microbes and earthworms.

2. It Adds Calcium to the Soil

The primary active component in agricultural lime is calcium carbonate. It adds calcium to acidic soil, which many plants need for healthy growth.

Some types of agricultural lime, such as dolomitic lime, also contain magnesium [1], another nutrient that plants need to grow.

3. Improves Soil Structure

In some clay soils, agricultural lime (garden lime) helps tiny soil particles stick together into larger crumbs. This improves soil structure, allowing water and air to move through the soil more easily.

4. Helps Plants Take Up Nutrients

When soil is too acidic, plants have a harder time absorbing essential nutrients. Adding agricultural lime raises the soil pH, making nutrients such as phosphorus more available to many garden plants [2].

Lime also helps reduce the harmful effects of excess aluminum and manganese, which can accumulate in highly acidic soil and slow plant growth. As a result, plants are often healthier and grow better when the soil pH is in the right range.

5. Protecting Tree Trunks

Some gardeners and orchard growers paint tree trunks with a mixture of lime and water (called whitewash).

The white coating reflects sunlight, helping prevent the bark from heating up during the day and cracking when temperatures drop at night. It may also help discourage some insects from resting or laying eggs on the trunk.

However, this is different from using agricultural lime to improve soil. Tree whitewash is a separate practice and is mainly used on young fruit trees in certain climates.

Garden Plants That Need Ag Lime

Plants that often benefit from agricultural lime in acidic soil include peas, cabbage, beetroot, squash, beans, asparagus, and lettuce.

Other plants that grow well in neutral to slightly alkaline soil include onions, lavender, spinach, garlic, and apples.

Plants That Don’t Need Lime

Garden lime is not suitable for all plants.

Plants that prefer acidic soil, such as blueberries, azaleas, rhododendrons, and sweet potatoes, usually should not receive lime unless a soil test recommends it.

Soil Testing

If you’ve recently moved to an area and aren’t sure of the soil pH, it’s a good idea to get a soil test.

Rainfall, fertilizers, and the natural breakdown of organic matter can slowly change soil pH over time.

Most garden plants grow best in garden soil with a pH close to neutral, usually around 6 to 7 [3].

However, plants cannot absorb soil nutrients if the pH is too acidic or too alkaline (too low or too high). Therefore, testing is vital before applying lime.

Home soil testing kits are available online and at many garden centers. You can use them yourself or send a soil sample to a local soil testing laboratory or agricultural extension office, if one is available.

Many soil tests are also affordable. They will also give you a good baseline of knowledge about the kind of soil you have.

When to Apply Garden Lime

The best time to apply garden lime is in fall because it has several months to work into the soil before spring planting [4]. However, you can also apply it in early spring if a soil test shows your soil is too acidic.

Since lime works slowly, the earlier you apply it, the more time it has to raise the soil’s pH.

How to Apply Agricultural Lime

As noted earlier, the method of application depends on the form of lime you’re using and where you’re using it.

Over a large area, such as a lawn, the push-broadcast spreader is the best method for applying pelletized lime.

For a smaller lawn, there are handheld spreaders with a hand crank that spray pellets a few feet ahead of you.

In vegetable gardens, spread the recommended amount of lime evenly over the soil and, whenever possible, mix or rake it into the top few inches before planting. For larger garden plots, spread it evenly and rake it into the soil.

How Often to Apply

Many gardens only need lime every 2 to 3 years, but always follow the results of a soil test.

However, if your soil is very acidic, a soil test may indicate that lime should be applied annually.

Caution

Be sure you are using the right type of lime for your garden. Also, follow the package directions for proper application and general safety precautions [5].

Quicklime (calcium oxide) and hydrated lime (calcium hydroxide) are caustic [6]. So, neither is recommended for home gardens because they can burn plants and skin.

Even with regular garden lime (aglime), which contains calcium carbonate, you should use it carefully, as too much can be harmful.

Always wear gloves and eye protection, and avoid breathing in lime dust when handling lime.

Too much lime can also make the soil too alkaline, which can stop plants from getting the nutrients they need.

Plants that are already stressed by drought, frost, or disease may be harmed even more if too much lime is added.

Soil that becomes too alkaline can cause leaves to turn yellow (called chlorosis).

Where to Buy

Garden lime is sold at most garden centers, farm supply stores, and many online retailers.

Takeaway

Agricultural lime is a simple way to raise soil pH when the soil is too acidic. When used correctly, it helps many plants absorb nutrients, grow stronger, and produce better harvests.

Always test your soil first, since adding too much lime can make the soil too alkaline and harm plants.