Not every one of us is blessed with fertile soil. Some of us grow vegetables or grass on our lawn, fertilize them and care for them as much as we could. Yet, somehow the vegetables have difficulty growing or the grass is growing in patches, not a thick green carpet that we would like it to be. It can be due to the soil being too acidic. If that is the case, then applying lime on grass can help.
Here, we will explain many things about lime. From what it is to when and how to apply it. We also have some tips in case you want to apply them to the soil. Let’s start.
Lime on Grass: What Is Lime?
Before you even think about applying lime on grass, you must first know what lime is. What is lime exactly? Lime is a soil amendment. As lime is made from ground limestone rock, it contains magnesium carbonate and calcium carbonate. When added to the soil, lime increases the pH of the soil, thus making said soil more alkaline and less acidic.
Although lime contains magnesium and calcium, both of which are essential nutrients that plants need, lime cannot be used as a substitute for fertilizer. The main role of lime is to alter the pH of the soil and offset its acidity, which may improve the availability of necessary nutrients in the soil.
Lime is widely available. You can find them easily in stores, both online and offline. Keep in mind that lime is used for various purposes (from cooking, water treatment, papermaking to construction), not just agricultural ones. So, before making the purchase, double-check whether the lime is for agricultural purposes or not.
Let’s take a bit of detour for now. Let’s talk about pH before we delve further about applying lime on grass. If you are a gardener, understanding pH will go a long way. So, what is pH exactly? Put it simply, it is a measure of a soil’s acidity or alkalinity/basicity.
Here are examples to put things into perspective:
- If the soil pH is 7, that means the soil is neutral.
- If the soil pH is below 7, the soil is acidic.
- If the soil pH is above 7, the soil is alkaline.
There are many factors that affect the pH level of the soil. Among these factors are nutrient content of the soil, soil type, rainfall, and fertilizer use. Let’s talk about each factor.
Note: to know the pH of your soil, you need to test it. Testing it will tell you not just the pH but also its nutrient content or lack thereof.
1. Nutrient content
The first factor is the nutrient content. Soil contains primary macronutrients (such as nitrogen, potassium, and phosphorus), secondary macronutrients (such as magnesium, calcium, and sulfur), and micronutrients (such as copper, zinc, iron, boron, and molybdenum). In soil with a pH above 6.5, there may be not enough nitrogen, potassium, phosphorus, magnesium, or molybdenum content.
When these deficiencies are present in the soil, plants grown in the soil will suffer from conditions like
- Poor growth
- Low resistance to disease
- Leaf-blades withering
- Decreased chlorophyll, resulting in yellowing
- Reddish leaf tip
- Decreased turf density
2. Soil type
The soil has something known as buffering capacity, also known as reserve acidity. Soil with rich organic matter or clay has the highest buffering capacity. The more buffering capacity a soil has, the more amount of lime is needed to alter its pH level. So if your soil has a high buffering capacity, it will need more lime on grass application.
Rainfall can also affect the acidity of the soil. Areas of high rainfall tend to have acid soils. The reason for this is because rainfall causes a soil to lose its alkaline nutrients. As a result, the acidity of the soil increases. Conversely, areas of low rainfall tend to have alkaline soils.
4. Fertilizer use
Fertilizing is needed to feed plants. The thing is, the use of fertilizer also affects the acidity of the soil. The more the soil is fertilized, the more it has nutrient content like nitrogen and phosphorus. As a result, the acidity of the soil increases. When you fertilize your soil, be sure to do it properly and avoid overdoing it.
Lime on Grass: Types of Lime
When it comes to applying lime on grass, you have two options: calcitic lime and dolomitic lime. Calcitic lime comes from limestone, marlstone, or chalk while dolomitic lime is made of the mineral dolomite. Each lime type has its own uses. Which one of them is best for your soil? That depends on the soil.
1. Calcitic lime
Calcitic lime is the ideal option when your soil but has enough nutrient content.
2. Dolomitic lime
Dolomitic lime is lime best used for soil that is acidic but it doesn’t have nutrient content deficiencies.
When you are shopping around for lime, please read the package labels carefully before purchasing it. Do not mistake agricultural limestone for non-agricultural ones. Agricultural limestone such as calcitic and dolomitic lime is different from quick lime (calcium oxide) and hydrated lime (calcium hydroxide). These non-agricultural lime cannot be used for agricultural purposes. So, please be aware.
What Does Lime Do for Your Lawn
Let’s say that you have determined that you should apply lime on grass. What does it do for your lawn? The first and foremost is that it amends the soil pH. If the pH of your soil is too low, lime increases it. In other words, it makes the soil less acidic and more alkaline.
As lime alters the pH of a soil, you can use it so that your soil pH can be ideal for whatever you want to plant in it. Since we are talking about lime on grass here, most grasses like pH range of 5.8 to 7.2. If your soil pH is too low, lime can correct it.
Amending the soil pH is not the only effect of applying lime on grass, of course. In addition to correcting pH, lime also adds magnesium and calcium contents into the soil. These two are necessary nutrients needed to preserve a lawn’s color and vigor as well as to protect the lawn from damage due to drought, traffic, or heat stress.
Calcium, in particular, helps to regulate other nutrients like phosphorus, copper, and zinc. Not only that, but lime on grass can also help to mitigate the undesirable effects caused by a buildup of nutrients like iron, manganese, and aluminum, which hinder the growth of plants. Lime further benefits the soil as it nourishes beneficial bacteria in the soil.
Why Apply Lime on Grass?
Here are some of the reasons why apply lime on grass:
- First and foremost, it balances the pH level.
- Adds magnesium and calcium, both are nutrients that grass needs to grow best.
- Lime on grass helps with not just new seed or new sod but also existing yards as well.
- It puts nutrients in the soil which otherwise may not be there.
- Benefits micro-organisms in the soil needed to keep a natural balance.
- Lime encourages thatches to decompose.
- Improves the effectiveness of fertilizer.
When to Apply Lime to Lawns
Unfortunately, you cannot measure the pH of soil just by looking at its appearance. So, don’t apply lime on grass right away if you see the grass in your lawn has difficulty growing. Lime is not a one-size-fits-all solution. You need to be very careful about this as a misstep can ruin the soil, which may take years to recover.
The ideal time to apply lime on grass is during winter. Why? Because during winter you are unlikely to apply treatments (like herbicides, for example) to the soil. When you apply lime during winter, you are essentially preparing for the next season. That being said, the season is not the only factor that determines the right time to apply lime.
Since we are talking about lime on grass here, you don’t want to apply while grass growing season hasn’t ended yet. Applying lime when the grass is growing will burn them. You don’t want that, of course. Another reason why winter is ideal is that the thaw/freeze cycle during the season helps lime to penetrate the soil.
How to Apply Lime on Grass
1. Testing to determine
Before you apply lime, you need to test your soil first. When you test a soil, you will know what kind of lime should you use, nutrient excesses and deficiencies. Be aware that every soil is different and you can’t know simply by seeing how the soil looks like. This is why testing is crucial.
Lime comes in two different forms: pulverized and pelletized. As such, the most effective application differs depending on the form.
As the lime comes in a fine powder form, it can be applied with various tools, even a simple one like a coffee can. Pulverized lime breaks down a lot faster than pelletized lime and is also cheaper. The downside of pulverized lime is that it can be airborne with the slightest breeze, thus posing an inhalation risk.
The limestone has been pulverized and bound into pellets. Products under this category generate less dust than their non-pelletized counterparts. Because the lime comes in pellets form, it can be applied using a broadcast spreader with no difficulty. As a binding agent is needed to make the pellets, it takes time before the lime breaks down.
Both pulverized and pelletized have their own advantages and disadvantages. Since no gardener situation is the same, there is nothing such as the best way to apply lime that works for everyone at any time. That being said, the best way to apply lime for you is the most effective one.
For example, while some gardeners find a drop-style spreader is not effective, you might find it effective to apply lime on your lawn. Or if you live in an area with windy days, pelletized lime will be the best option as it generates less dust, even if it is relatively more expensive.
3. Timing and intervals
Winter is the ideal time to apply lime. However, if it isn’t possible to apply lime in winter, applying in fall is not a bad idea, either. Fall is also a good time because it gives lime the opportunity and time to work into the dirt before the upcoming growing season arrives.
Another reason why fall is a good time to apply lime is that cold temperatures and rain during the season helps lime to penetrate the soil. Also, lime should not be applied to wilted grass or grass covered in frost. Liming is beneficial and all but never overdo it. Limit liming only every 3 to 5 years.
4. What if it doesn’t work?
There is no such thing as a one-size-fits-all solution. Of course, that includes liming too. In some cases, applying lime does not improve the lawn. If this happens to you, you may want to test the soil again. It is not uncommon to find the soil becomes too alkaline, has iron issues, or poor nutrient uptake after liming.
Some Useful Tips for Applying Lime on Grass
- Aerating the lawn can help lime reaches deep into the soil
- If you are starting a new lawn, liming can be very beneficial for the process.
- You can apply limestone with various tools. Rotary-type spreaders are among the most effective.
- Apply lime when the winds are calm.
- For best soil coverage, divide the lime into two halves. The first one is spread in a single direction, the other one in a criss-cross pattern.
- Lime alters the pH of the soil but some plants grow well in acidic soil. If you have any of these plants, keep lime away from them.
- Lime takes about 2 years to move 2 inches deep into the soil. To avoid overliming, lime every 3 to 5 years.
- If you cannot lime your lawn by yourself, consider having the job done by a lawn care professional.
Now that you have a better understanding of lime, you are better equipped to apply or not apply lime on grass. Keep in mind that lime is not a one-size-fits-all solution. Before you apply it, assess the soil properly. Make sure that your soil really needs lime. Only after that can you apply lime.