Lawns are incredibly popular in the U.S., to the point that 81% of all Americans have one. With all the nutrients from these lawns’ grass clippings, it can be extremely beneficial to recycle them back into the garden, such as using them as a mulch for fruit trees. Unfortunately, grass clippings get thrown out and end up in landfills, which means lawns quickly lose nutrients and become barren. Fortunately, there are ways to use grass clippings and keep those nutrients on your property! While grass clippings usually make a good mulch, let’s take a closer look to see if they’re good for fruit trees in particular.
Grass clippings are a good mulch for fruit trees as they prevent weed growth, help the soil retain water, and provide a slow breakdown of nutrients. They also have an NPK of 4-2-1, which is a great fertilizer for fruit trees. Grass clippings are best applied when they’re dry and in 1-2 inch layers.
So, while grass clippings are good for fruit trees, what exactly do they do to help fruit trees and are there times when they can damage fruit trees?
How Do Grass Clippings Help Fruit Trees?
Using grass clippings as a mulch for fruit trees helps fix the soil by adding nutrients and moisture, and reducing the number of pests. Grass clippings have a high amount of nitrogen, which many fruit trees need to grow and develop fruit properly.
Grass clippings have good levels of nitrogen, phosphorus, and potassium (the three main nutrients plants need, also called NPK). The NPK of grass is 4-2-1, and since fruit trees commonly need high amounts of nitrogen to thrive (especially citrus trees), it makes a great mulch for them.
Since grass clippings are already fairly thin and small, they can break down rather quickly and provide quality nutrients to the soil. This helps build soil health, which invites beneficial organisms such as earthworms and soil microbes. The worms and bacteria in the soil help breakdown these nutrients even further, which the fruit tree’s roots can then use.
A good layer of grass clippings can also help the soil retain water as it prevents some evaporation in the ground and blocks the hot sun from drying it out. Not only that but with the increases in nutrients and soil richness, even more water is retained. Research shows that every 1% increase in soil richness can result in the soil holding 20,000 more water per acre.
Grass clippings can also smother weed growth, meaning you won’t need to weed as often (less work for you!).
But while grass clippings can clearly benefit fruit trees in several ways, can they also cause them harm?
Can Grass Clippings Hurt Fruit Trees?
Grass clippings can damage fruit trees if they’re applied when wet or have pesticides or herbicides. These chemicals can add up in the soil and kill the fruit trees over time. Using wet grass clippings can introduce mold and rot, which can increase the chance fruit trees develop a disease.
Additionally, grass clippings have a pH of 8.5, so they’re pretty alkaline. Since most fruit trees prefer a slightly acidic soil pH of 6.0-7.0, adding too many grass clippings can be harmful to fruit trees. If the soil pH is outside of the preferred range of the fruit tree, it will have a hard time absorbing nutrients from the soil and will slowly die off (keep in mind that soil pH is constantly changing, so the pH of grass clippings will also change as they decompose).
For an easy way to measure pH in soil, consider using a pH meter. To see which pH meter I recommend, you can check out my recommended tools page.
Aside from pH, many lawns are treated with herbicides and pesticides. By adding grass clippings from these lawns, the chemicals can quickly build up in the soil and kill the fruit trees (as well as other plants).
There are also times when the grass clippings contain seeds or other weeds in them. This means weeds can grow at the base of your fruit trees and compete with them. Fortunately, providing a 1-2 inch layer of grass should smother out most, if not all weed growth.
If you find that weeds are growing, then consider composting the grass clippings first to kill the seeds and weeds. Like grass clippings, compost can also be applied to the top of fruit trees’ soil in 1-2 inch amounts (just make sure not to apply it more than once every few months and that the compost doesn’t touch the trunk).
Let’s explore how to apply grass clippings as mulch and how to avoid these problems.
How To Use Grass Clippings as a Mulch for Fruit Trees
Once you check that the grass clippings aren’t treated with chemicals, you can apply them as a mulch for your fruit trees by first drying them out. From there, add them to the top of the soil in a 1-2 inch layer. Make sure to keep it at least 3 inches away from the trunk of the fruit tree. Apply at most every 2 weeks.
Since most lawns get mowed about every 2 weeks, this can amount to a lot of grass clippings. Fortunately, grass breaks down fast and doesn’t contain a high level of nutrients, so you can reapply a new layer of clippings to your fruit trees every 2 weeks as well.
Here are some steps to applying grass clippings as a mulch for your fruit trees:
- Check that the grass isn’t treated with chemicals
- After cutting the grass, lay the clippings out to dry for a couple days
- Once dry, apply to the top of the soil in a 1-2 inch layer
- Keep the clippings at least 3 inches from the trunk of the tree
- Reapply every 2 weeks at the most
It’s helpful to dry grass clippings before using them, as wet clippings can clump and suffocate the soil. This can quickly create mold and rot, which can damage your fruit trees. You can dry your grass clippings by laying them out on a tarp, driveway, or anywhere else in the sun. After a couple days they should be dry.
Remember to keep the grass clippings 3 inches away from the fruit tree’s trunk since the nutrients can chemically burn the tree or introduce mold.
What To Do With Treated Grass
If you do find that your grass is treated with chemicals, it’s best not to use them on your fruit trees as it can damage or kill them. While one application of grass clippings likely won’t do much to the tree, a continuous application can stack the chemicals in the soil, eventually causing damage to the roots and the tree.
However, you still have a few options to process grass clippings that are treated:
- Compost them
- Toss them in the green bin
While I wouldn’t advise adding them to your compost pile, you can do so if you’d like. As the compost breaks down over the next 3-6 months, some of the chemicals in the grass will leach out, providing you with a slightly cleaner material.
Although, treated grass typically isn’t good for any part of the garden, so it’s likely not worth the risk. It’s best to buy or use other forms of mulch that are untreated.
If you’d like, here are some other mulches that also work well for fruit trees:
- Pine needles
How Many Grass Clippings Should You Use on Fruit Trees?
It’s best to use enough grass clippings for a 1-2 inch layer of mulch around fruit trees. While you can apply more than this, you may find the grass will begin to become moldy or rot. If you have extra grass clippings and aren’t sure what to do with them, consider adding them to your compost bin.
While there is a limit on how much grass clippings you can use around fruit trees, the good news is that they’re light on nutrients and decompose quickly. This means you can reapply them every 2 weeks without much chance of overloading the soil.
As mentioned, if you have a rather large lawn, and have a ton of grass clippings on your hands, consider composting them. They should be ready once they decompose in 3-6 months and will be a great fertilizer for your fruit trees. Just remember that grass clippings are usually a wet, green material, so add dry and brown material in your compost to balance it out. This can be leaves, bark, paper, or the like.
When Should You Apply Grass Clippings to Your Fruit Trees?
The best time to apply grass clippings to your fruit trees is in the early spring. This is helpful since fruit trees need a lot of nutrients to support their new growth, which includes leaves, flowers, and fruits. However, because they’re light on nutrients, grass clippings can be applied every 2 weeks until the fall.
Grass and fruit trees often start their new growth at the same time (in the early spring). This means cut grass can be added as a mulch at just about any time when the grass is growing. In areas that have growing seasons year-round (such as Florida and California), grass clippings can be used any time of year.
Since grass clippings are fairly light on nutrients and decompose in soil quickly, they can be applied every 2 weeks. To prevent overloading your fruit tree with nutrients and mold buildup, it’s best not to apply more often than this.
When in doubt, consider composting your grass clippings as they’ll add plenty of nutrients to the piles. You can then use the compost in 1-2 inch layers as a fertilizer in the early spring and late summer.