If the grass in your lawn is yellowing or weed-infested and fertilizers don’t seem to help, you most likely need to apply lime to your lawn. You should perform a soil pH test to determine if your lawn is too acidic, which inhibits grass growth. By adding a lime treatment to your lawn, you alter the pH balance of the soil, making it more friendly to plants and allowing them to absorb nutrients.
Before investing in fertilizers and weed killers that might only damage your soil further, you should evaluate if it’s time for lime treatment. Knowing how to tell if your lawn needs lime, mixed with a little bit of investigative work and testing can go a long way. A well-limed lawn will thrive with fewer fertilizers and push out invasive weeds.
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What is Lime?
Lime is a soil amendment made from pulverized limestone. It contains a compound called calcium carbonate, which introduces calcium to the soil and reduces soil acidity. Ground limestone is a natural, non-toxic product that is used in many agricultural practices. It also brings big benefits to your lawn.
The two types of lime you will commonly see for sale are:
- Calcite Lime: Considered the “standard” agricultural lime, calcite lime contains high levels of calcium as an agent for reducing soil acidity.
- Dolomite Lime: Dolomitic lime contains much higher magnesium levels than calcite lime, but will also reduce soil acidity.
The bottom line is, both calcitic limestone and dolomitic limestone will achieve the results you need in your lawn. In most cases, we recommend going with the most cost-effective lime product, as highly specialized magnesium and calcium needs are pertinent for large-scale agricultural operations than improving lawn health.
7 Signs Your Lawn Needs Lime
1. Yellow Grass
Lawn grasses thrive in soils with a pH level between 5.8 and 7.0 (the lower the pH, the more acidic the soil is). When soil becomes too acidic and has a low pH level, microbial activity is affected and plants and grasses cannot effectively extract nutrients from the soil. If your grass is yellowing, dying in patches, or grows weakly despite your lawn care efforts, there is a very good chance you need to add lime.
Soils become more acidic over time, due to natural nutrients being pulled from the soil by factors such as water runoff and application of certain fertilizers. If nothing else in your lawn care routine has changed but your grass is struggling more than ever, the soil acidity has probably risen.
2. Weed Infestation
Many weeds thrive in acidic soil. Dandelions, one of the most common and most aggressive weeds, grow best in soils with high acidity. If you’ve noticed an increase in weeds among your lawn grass, it’s likely time you limed your lawn to push out these invaders.
3. Fertilizers Have No Positive Impact
Lawn fertilizer is naturally the first solution that comes to mind when a lawn looks sickly. As a lawn care enthusiast, want to see a healthy lawn. Our impulse is to feed our grass nutrients to encourage growth.
However, if your soil is too acidic, even increased fertilization won’t help your grass. High-acid environments inhibit plants from gathering soil nutrients, and overfertilization with things like a can even lead to increased soil acidity. When fertilizers won’t work, it’s a sign that you need to consider liming your lawn.
4. Moss in the Lawn
Like weeds, mosses love acidic soil. Look in shaded, moist areas. If you see moss growing at the base of trees and stretching out toward the main portions of your lawn, this can be a key indicator your lawn would benefit from a lime application.
5. Sandy or Clay Soil
Certain soil types are naturally more acidic. Clay soils tend toward the acidic side, while sandy soil encourages runoff that can pull calcium and other pH-balancing agents from the soil. If your lawn is built on a bed of one of these soil types, it likely needs lime. To keep grass growing well in sandy soil, you will need to apply lime every 2-3 years.
6. You Experience Excessive Rainfall
Whether it’s an atypically wet winter on the west coast, a barrage of storms in the south, or a boggy spring in the northeast, excessive rainfall can result in the need to add lime to your lawn.
Water naturally pulls calcium and magnesium from the soil, which results in a more acidic pH. If you’ve had intense weather patterns in recent years or live in a region that experiences heavy precipitation, you’ll need to add lime to your lawn to combat rising soil acidity.
7. Poor Drought Recovery
A well-cared-for lawn can sometimes present a strong front even as soil acidity rises. But, if your lawn is put under stress from drought or a period of intense heat and won’t bounce back, it’s a sign your lawn needs a lime treatment.
Grass needs extra nutrients during drought recovery, but acidic soil will choke the plants of life. If your lawn limps out of summer, prepare to add lime in fall.
Soil Testing pH Level Before Adding Lime
If one or more of the signs listed above are present in your yard, it’s time to take the next step. Before you purchase lime and go through the steps liming your lawn, perform a soil pH test.
Testing your soil’s pH level will:
- Let you know definitively if you need a lime lawn application.
- Let you know how much lime you need to add.
- Establish a benchmark for future testing, so you can see the results of lime and other soil additives.
There are 2 types of soil ph tests:
- At-Home Soil Test: Soil pH testing kits are available from home and hardware stores. They are generally inexpensive and can give you a good baseline to make sure you’re on the right track in discovering soil acidity. However, a soil test kit is not completely accurate and won’t usually give you the detailed information necessary to determine the amount of lime your lawn needs.
- Soil Test via University Agricultural Extension: For the most accurate pH level information you can get, have your soil tested by the local extension in your area (if available). These tests are inexpensive, accurate, and deliver fast results. Simply do a search for the agricultural extension in your area and enquire about soil sample pH testing. For instance, in upstate New York, the Cornell extension offers soil testing at a lower cost than at-home kits and delivers results in 5–7 business days.
When the option to test with an extension is available in your area, choose to do so whenever possible. A few days’ wait is worth getting the most accurate results about what your soil needs, especially if you don’t know what type of soil you have.
Low pH Lawn Symptoms and Acidic Lawn Signs
Some of the easiest signs and symptoms of low soil pH levels include:
- Loss of green color
- Inability to recover from extreme heat
- Moss buildup
- Poor overall grass growth
- Lawn soil type is naturally more acidic
Does Your Lawn Need Lime?
A lawn that is yellowed, can’t recover from drought stress, or is being overgrown by weeds and other invasive plants is generally in need of lime treatment. Liming reduces soil acidity and encourages grass growth. Once you’ve identified how to tell if your lawn needs lime, be sure to test the soil pH level. If possible, contact a university extension for the best soil testing results.
Once you’ve identified the problem and know how severe the soil acidity is, and your soil type, you can proceed with a lime application to your lawn to promote better grass growth.