Do You Really Need to Mulch Your Garden Every Year? Here's What Experts Say

Mulching a garden comes with plenty of benefits. Mulch helps prevent weeds, improve moisture retention, and control soil temperature. But is mulching your garden beds something you need to do every year? While this gardening practice ultimately comes down to personal preference, there are some things to consider when it comes to how often you lay down fresh mulch. Ahead, experts share their thoughts on whether or not you really need to mulch every year. 

Do You Need to Mulch Every Year?

No, you don’t have to mulch every year, but doing so can benefit your garden. Choosing to mulch isn’t a one-size-fits-all task and depends upon several factors. "It comes down to personal preference, budget, and how much time and effort you want to put into your beds," says Celina DeBrito, head gardener at Pippin Hill Farm & Vineyards. "If you’re mulching large areas, it can become expensive."

Hence, some home gardeners might avoid annual mulching to save money and cut expenses. To cut costs, DeBrito recommends buying in bulk or shopping during sales. And while shredded hardwood tends to be the mulch standard, you can also opt for pine bark mulch or pine straw mulch as alternatives.

Benefits of Mulching

Mulching your garden beds has several benefits, making it a worthwhile annual task.

• Improves water retention: "It helps with water retention in the soil by keeping in moisture during the summer," says DeBrito. This means you don’t have to water your plants as often, saving you time outside. "And, in the winter, mulch can help keep heat in the ground and protect plants through the colder months," she says. 
• Prevents weeds: Gardening expert Janet Mavec notes that mulch can help suppress weeds. Mulch prevents sunlight from reaching the soil, starving weed seeds of the light they need to germinate. The additional layer also makes it difficult for young weeds to push through the mulch.
• Minimizes soil erosion: Mulch can also help reduce soil erosion, Mavec says. Water can erode your soil over time, but mulch helps prevent this by reducing the impact rain and water drops have on your soil.

When and How Often to Mulch

While you don't need to do it every year, there are some telltale signs that your garden needs a fresh layer of mulch. DeBrito prefers to do most of her major mulching in mid-spring, once the perennials start to grow and are easy to identify. “Selective mulching in the fall can also be quite beneficial to protect tender bulbs or perennials,” she says.

The Layer of Mulch is Thinning

Thin layers of mulch don’t provide much benefit. If the depth of the mulch is less than 2 inches deep, it could be time to re-mulch, says Lindsay Springer, director of plants, nutrition, and digital agriculture at Gardyn. "The mulch will decrease because of the continuous breakdown of the mulch near the soil," she says. When there’s not a thick enough layer of mulch, there will be less moisture retention, and your soil and plants will dry up.

The Mulch Harbors Fungus

Mulch can be a breeding ground for fungus. "Especially when there’s prolonged rainy weather, the excess moisture and anaerobic conditions of soaked mulch can kick off quite a lot of fungal growth," says Springer. Fungi accelerate the decomposition of your mulch, and slimy layers tend to reduce airflow to roots, she adds. To get rid of the fungus in your mulch, she suggests using a rake to break up the old layer before adding fresh mulch on top.

Your Mulch Has Excessive Weeds

Mulch is supposed to help get rid of weeds. If the opposite is happening, the mulch isn’t doing its job, and it’s likely time for another layer or two of new mulch. "As your mulch breaks down over time, weeds will find their way to soil nutrition and start to pop up more than before," says Springer.

What to Do Instead of Mulching

If you don't mulch annually, there are other ways to keep your garden beds in tip-top shape. Experts say to stay on top of weeding and enhance your soil with compost. "Check the pH of your garden bed soil and amend or fertilize accordingly," DeBrito suggests. "Add other organic matter to beds, such as compost, leaves, or grass clippings." Another alternative Mavec suggests is to save the fallen leaves from your yard and lay them down in beds in early spring before the weeds wake up.