A bright, green, grassy lawn can be one of the most picturesque parts of a home. A lush, healthy lawn can do wonders to make the whole house look well-tended, homey, and welcoming. But lawns are always as easy to maintain as we might like.
Depending on the soil quality, a lawn can be incredibly difficult to keep green and growing without weeds and other problems.
Grass is a plant, and like all plants, it needs water, nutrients, and the right soil pH. Meeting those needs will help your lawn thrive and fight off intruders like weeds and diseases. Lawn lime can be a key element to a healthy lawn.
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What is Lawn Lime?
If you hope to improve your lawn, you’ve probably heard of lawn lime. There are big bags of “lawn lime” for sale at the yard and garden store, and neighbors may have mentioned “liming” their lawns to improve grass health. But what is lawn lime, and how does it help?
Lawn lime is a soil amendment – something you add to the soil to improve it. In this case, you’re improving the pH of the soil by adding ground limestone. Ground limestone contains calcium carbonate and magnesium carbonate, which make the soil less acidic and more alkaline.
Most grasses prefer alkaline or neutral soil pHs, so if you have particularly acidic soil, liming will have to be a regular part of your lawn care. If you have more alkaline soil, it’s unlikely liming will help improve your lawn.
That’s why it’s important to test your soil before amending it. Just because lime saved your brother-in-law’s lawn doesn’t mean it’s the right product for yours.
Not A Fertilizer
Despite containing two essential plant nutrients, calcium and magnesium, lawn lime isn’t a fertilizer. Liming your lawn is not a replacement for fertilizing. While altering the soil’s pH will help your grass access the nutrients in the soil, it’s not appreciably adding nutrients.
The ideal soil pH for most grasses is anywhere from 6.2-7.2. A neutral pH is 7.0. Below 6.5, your soil is considered acidic. While there are a few, hardy grasses like centipede grass and ryegrass that can thrive on acidic soil, most grasses need to be in alkaline soil to grow well.
When soil pH strays too far toward an acidic pH, the plants can’t access the nutrients in your soil. If you test your soil, you may find that it is rich in nutrients. The problem is that the plants can’t access it because the pH is all wrong.
If the pH is wrong but your soil has nutrients, you’ll only need to add lime and not fertilizer. But, you might discover that your soil is both acidic and low in nutrients. If that happens, amend the soil with lime first and then fertilize with a grass specific fertilizer.
How Do I Know My Soil Needs Lime?
The best way to know if your soil needs lime is to get it tested. You can buy soil testing kits at your local farm and garden store, but the quality of these tests varies widely. Some are pretty accurate, and others are useless.
Choose one like the MySoil test kit that has lots of positive reviews and a good reputation.
Another way to test your soil is to send a few samples to your local county extension office.
The extension office can give you a complete soil profile, including not only your pH and nutrient levels but also information on the soil type and the types of lime and other amendments that might help.
If your soil is very acidic, you should test and amend it yearly until a balance is reached. It’s too harsh and difficult to make dramatic alterations to the soil pH. Once you’ve got the soil where you need it, test every three years to make sure it’s still on the right track.
Obvious Signs of Imbalance
Most people don’t bother testing their lawns until they see signs that something may be amiss. There are a few obvious indications that your soil pH is too low to sustain your lawn.
When lawn soil becomes acidic, you’ll see the lawn grass start to suffer – turning brown or patchy. At the same time, acid-loving plants like mosses and weeds move in and spread quickly. If you start seeing a lot of dandelions and knotweed, it’s a sign you’re likely dealing with an acidic or depleted lawn.
An acidic lawn won’t respond to fertilizers. When you feed the ground, you won’t see any improvement. Remember, this is because acidic soil makes it much harder for grasses to access the nutrients in the soil.
When to Apply Lime
Generally, you start to notice soil imbalances in the spring and summer, but the best time to apply lime is usually in the fall.
Of course, you can apply lime at any time, but the lime takes time to seep into the soil and alter the soil pH. It’s pretty much just crushed limestone, after all. The balancing effects need time to create visible change in your lawn.
If you can, apply lime in mid-fall and give it all fall and winter to break down. The fall and winter weather: rain, cold, freezing temperatures, snow, and thaw help to break down the lime and enable it to work on the soil.
If you can’t apply lime in the fall, look for an “anytime” variety of pelleted, granular, or liquid, quick-acting lime. This pelletized lime is processed to break down quickly and improve your soil in a shorter period of time.
Even when using quick lime, avoid liming your soil in the height of summer. Heat can damage the chemical breakdown of the lime and cause an increased imbalance in the soil.
You should also avoid applying lime after the hard frost in winter. When the ground is hard-frozen, the lime won’t break down properly until springtime.
How Much Lime Do I Need?
Quantity depends on your soil. A good soil test will tell you how much lime you need to balance your soil. The pH level isn’t the only issue you have to take into account, either. Soil type also matters. Clay soil requires more lime to balance out than sandy soil.
It’s better to under-lime than over-lime. Overliming your soil will cause an imbalance in the alkaline direction. Then, you have to course correct temporarily by mulching with an acidic mulch.
Or, you’ll have to have a professional lawn company come in and repair the damage. If you don’t have a great, reliable soil test handy to tell you how much lime to use, under-estimate your lawn’s needs and be prepared to retest and re-apply at a later date.
Follow the manufacturer’s directions carefully. They’ll have recommendations for how much to add. Typically, they’ll tell you how much to add to alter the pH by a certain amount. That’s why you need to know what your pH is to begin with.
How To Apply Lawn Lime
Powdered limes can be challenging to apply. They’re also messy and, if inhaled, can be a health risk. The powdered lime should be applied with a tiller or a drop spreader. If you don’t have either of these, you should go with pelleted, granular, or liquid lime.
Pelleted or granular lime can be spread with a fertilizer push-spreader. The pellets are easier to contain, and you don’t have to worry about a stray breeze spreading lime powder all over the neighborhood.
Spread the time as evenly as possible over the soil, then water the whole lawn deeply. This watering will help start the breakdown of lime into the soil. Watering will also keep the lime in contact with the soil, where it will work its magic.
Health Concerns with Lawn Lime
Lime is a natural material, but that doesn’t mean it can’t cause some harm. Powdered lime can be a health risk if you inhale it. It’s ground-up limestone, and limestone doesn’t do wonders for your lungs.
People working with powdered lime should wear a mask that protects them from fine particles. Goggles can help protect the eyes from blowing lime powder. Don’t apply powdered lime on a windy day to minimize the risks of irritation.
When you’re working with pelleted lime, you don’t have to worry about breathing in powder, but both types of lime will irritate the digestive system of people or animals who consume them.
Most people and animals aren’t going to be interested in eating lime pellets, but there’s always one or two who are. Keep your children and pets away from a freshly limed lawn, just in case they decide to see what those little pellets taste like.
Give your lime a few days of watering and care to soak into the soil before you let children and pets roam freely again.
Changing PH Levels
Soil levels are changing all the time. Heavy rainfall, fertilization, plantings, irrigation, and the basic soil composition will change the pH over time. If your soil is alive, the pH will change with time and use.
If you’re liming to improve acidic soil, apply one treatment and then test again. Ideally, apply your lime in the fall, test in the summer, and apply more lime – if needed, in the fall again.
If your soil is very acidic, test once a year for a few years. Then, as the soil balances out, test once every 3 years. This will allow you to keep an eye on the shifting pH of your soil. Then, you can spot acidification before it damages your lawn deeply.
