Lime for the Garden
Why, When NOT to, What, How to and How much!
Let's take some of the mystery out of the process of adding lime to the garden...
Lime for the Garden - Why?
Applying lime to the garden is an age-old method of improving acidic soils. Mixing lime into stiff or clay soil, it tends to make it friable and easier to work and promotes better drainage. Lime can also be used in loose sandy soils that don't hold water well, to help the garden retain water better.
Lime in your garden also a variety of additional benefits:
- Lime is used in the garden to reduce acidic soils to a level that plants prefer (important for plant health).
- Lime provides the garden soil with calcium (needed for plant health).
- Lime promotes beneficial bacteria which help in breaking down organic material in the soil. This process helps supply nutrients for your garden plants.
When NOT to use Lime in the Garden?
It is NOT recommended that you use lime in your garden, if your soil pH is alkaline already. Lime will only make it even more so, called "over liming." Soils that are too alkaline can be just as harmful to plant health as those too acidic. Yellowed plants throughout the garden are often a sign of over-liming.
Test you garden soil's pH level first, to determine if it's needed. A neutral soil is generally considered to be that with a pH of 6.0-7.0
Lime for the Garden- What is it?
There are several different types of available lime for the garden. For all but the pelletized variety, you'll want to make sure that it is ground very finely, for best absorption.
Ground Limestone (also called Agricultural Lime)
Ground limestone is the most commonly used form of lime for the garden. It takes longer to break down, so provides a slow-release action in your soil. As a result, it will take longer for you to see the results in the soil. On the flip side, it will help improve the soil's acidity for a longer period of time.
Note: Ground limestone is less caustic than the other forms, which is good in that it leaves a little more room for error... but you will need more of it to affect the pH level.
There are two types of ground limestone:
This is the form of Lime that's most commonly used and recommended.
Dolomitic Limestone is a limestone mix that has dolomite added. It has a high magnesium content, so only use dolomitic limestone if your soil has a significant magnesium deficiency.
Pelletized Lime gives you the best of both worlds. It is easier to apply and is fast acting. The downside: it is significantly more expensive.
Note: If selecting pelletized lime, be certain of the type that you're picking. It is produced with both calcitic and dolomitic limestone.
Burnt Lime (Quick Lime)
Burnt Lime is lime that has been heated. This process makes the lime faster-acting.
Note: Use burnt lime in the garden only when there are no crops carrying over, as it can burn the roots.
Lime that's had water added in the processing is called hydrated lime. It is fast-acting in the soil, but the affects on the pH level in your garden also don't last as long.
Note: Use hydrated lime in the garden only when there are no crops carrying over, as it can burn the roots.
Gypsum is often referred to as lime, but it does not have the same effect on the soil. While applying gypsum to your soil will improve calcium levels, it will not affect the soil's pH level in a significant way.
Lime for the Garden - When?
Fall and/or early spring are the best times of year for applying lime to the garden soil.
Allow sufficient time before planting for the soil and lime to mix and meld (in other words, it's best to do this a good while before planting time).
Lime for the Garden - How Much?
Gauging how much lime to apply to your garden is a little tricky.
*We recommend always erring on the side of caution... if in doubt, apply less lime in your garden. You can always add more later.
The lighter the texture of your soil, the more quickly the lime works. So, if you have sandy soil, it will take less lime to reduce the garden's pH level to one that's less acidic. Heavy clay soils will require the most additive. Loam and silt soils come in second. Thus, with sandy soils, it is fairly easy to over-lime. Clay, not so much so.
NOTE: Correcting soil where you've added too much lime, can be very difficult and take a very long time. Therefore, it is STRONGLY recommended that you consult the extension office in your county for recommendations for ratio of application for soil in your area. Also, there should be an application chart/guideline on the package of your lime/limestone. If you are unsure of the application ratio, opt for a lighter application, and adjust it over time.
Lime for the Garden - How to Apply?
Apply the lime/limestone to your soil following the recommended disbursement for your soil type. Rake it in to the top level of soil in your garden plot. (The majority of your plants' roots will be near the top, so this is where it will be feeding most heavily from the soil).
Test the soil again at a later date, to gauge your success. Note: the lime will not become active in your garden soil until it has interacted with water.
Note: When applying lime by hand, you may want to consider wearing long clothing, gloves, and even glasses/face-mask (to avoid breathing the particles).
Tips From Our Readers:
Have a great idea to share? Submit your own tips to us at: firstname.lastname@example.org
Note: the advice and information contained herein is based upon our experience and study. As with any advice, please apply at your own discretion.