Mulch Reduces Weeds
Lessen the amount of weeding work you have to do in your garden by putting down mulch. A blanket of mulch three to four inches deep will smother weeds and keep weed seeds from sprouting. Weeds that do pop up will be easier to remove, since their roots won’t go deep into the soil.
Find out how much you’ll need for your garden using our Mulch Calculator.
Mulch Encourages Earthworms
Organic mulch encourages earthworms to move in. The worms dig tunnels that help bring air and water into the soil. They also break down leaves and other organic materials. Their waste is excreted in the form of castings. Castings act like a kind of fertilizer, helping plants grow.
If you see earthworms in your garden or potted plants, that’s usually a sign that your soil is healthy. Earthworms use organic mulches like pine straw and compost for food and shelter, but you won’t find them in rubber mulches, pebbles used as mulch or some mulches made from dyed wood chips treated with chemicals.
Mulch Protects Against Temperature Changes
Mulch helps regulate the temperature of the soil. Plant roots stay cooler when the temperatures rise. In the winter, mulch helps the soil stay warmer to protect the roots from the cold.
Avoid piling mulch against tree trunks or plant stems in volcano-shaped mounds. Mulch that touches your plants acts like a bridge to let pests infest them. Instead, put the mulch in a doughnut shape around plants. Keep it at least a couple of inches away from trunks and stems.
Layer the mulch two or three inches deep, so water and air can still reach plant roots.
Tip: Don’t let mulch touch your house or other structure. Termites can use it to get into wood and wood products.
Mulch Retains Water
Mulch helps shrubs, trees and garden beds retain moisture. You’ll still need to water your plants, but you may be able to water less often and save money on your utility bills.
A drip irrigation system or soaker hose is the best way to water, so the water has time to soak into the soil and reach plant roots without running off. In general, coarse mulches like pine bark let water pass through more easily than finely shredded mulches.
Mulch Adds Nutrients
Organic mulches eventually decompose, and that’s a good thing. As they break down into soil, they provide nitrogen and other nutrients to your plants. However, fresh wood chips can actually tie up nitrogen as they decompose, so use them only as a top layer of mulch or let them age before using them. They’re better to use around shrubs and trees than around annuals and vegetables. As mulch biodegrades, it provides nutrition to your plants, so they can grow strong and healthy.
Mulch Helps Prevent Erosion
Watering and rainfall can wash away your soil, but mulch helps prevent erosion. It lessens the impact of the water droplets as they hit the ground. Heavy mulches can help control erosion in areas with strong winds.
Mulch can also help keep the soil from compacting in areas that get a lot of foot traffic. For best results, add more mulch as needed. Find out about the types of mulch in our buying guide.
Mulch benefits your plants by smothering weeds, inviting helpful earthworms to move in, regulating the temperature of the soil, retaining moisture, providing nutrients and preventing erosion. Use a two or three inch layer in a circle around your plants. Don't let the mulch touch their trunks or stems.
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