Why do lawns need lime and how do you know when you need it? I’ll try to answer some of these questions for you, but first you should know is why lime is used on lawns.
Soil ph is a measure of the soils acidity or alkalinity. If your ph level is below 7.0 then your soil is considered acidic and if it’s above that number, it is considered alkaline.
A desirable ph level is between 6.0 and 7.0. Lime conditions the soil and will improve the growth of turf and make it healthier. With a good ph factor a lawn has less of a chance of loss of nutrients and thatch is reduced. Soil acidity increases with an increasing rainfall.
Some of the things that can cause acidity in lawn, other than rainfall, some fertilizers also leach the nutrients from the soil. Other factors which cause acidity are irrigating with water that has a high acid content and decomposition of soil organic matter.
Test the Soil
The only way you can determine if your soil needs liming and how much to apply is to do a soil test. A soil test kit can be found at your local garden center to test your lawn’s ph level but it won’t tell you how much lime to use to make your lawn healthier.
The only way to determine how much lime you need is to have an actual soil test by the county extension office. If they don’t have the facilities to test there, they can tell you where to send your soil for testing. They should be able to tell you how to collect the soil needed for testing.
You will receive a test report when the test is completed, and in that report there is a section titled Lime. If there is a zero in that section, you don’t need any lime at all.
If you see a letter T or M‚ with a number following, that indicates you need lime. The letter M stands for pounds per 1000 square feet. Homeowners will normally not see the letter T because it is the indicator of tons per acre.
Types of Lime
There are a couple of different forms of lime. You will find pelletized lime or powder lime. Pellet sized lime is easier to apply and creates much less mess. Powdered lime, even though it is less expensive it is very messy and hard to spread. It has the consistency of baking flour.
The finer the particle size of lime the faster it will have an affect on soil ph. Applications of lime are best when mixed with the soil with a roto-tiller or using a core aeration machine that pulls out soil plugs.
It is recommended that lime application and fertilizer applications be separated by at least two weeks. There really isn’t a specific time to apply lime.
It can be applied anytime during the growing season. It should not be applied when the grass is wilted or frost covered. It will help improve turf growth because grass grows better when the soil ph is improved.
Lime is completely natural, as it is crushed limestone. Homeowners mistakenly think that they need to apply lime every year to keep the necessary ph level. There are negative aspects of creating a too high ph level as well as of having too low a level. A high ph level prevents nutrients such as nitrogen phosphorus; potassium sulfur and other nutrients are less available.
With these nutrients less available, it makes your lawn less vigorous and healthy. Once your ph level is adjusted to the proper number, you can maintain the correct level by combining one pound of lime to every pound of fertilizer used. You only need to have your soil tested once every three years or so after, it’s initially tested.
The question has been asked if liming your lawn will eliminate moss. It won’t do that; the only way it helps eliminate moss is by allowing the turf to grow stronger and healthier.
Any way you look at it, lime is an essential ingredient for a healthy lawn. If your lawn is not healthy and has an abundance of weeds, test your soil. If you find your ph level is not at a high enough standard for a healthy lawn, then you can use lime to help your lawn grow green and strong.
Remember, sturdier grass and healthier lawns are a deterrent to those nasty weeds we don’t like to see cropping up in our yards.
Photo by flickr user Horia Varlan