How to Keep Your Garden Well-Mulched (and Why You Should)

People think of mulch as something that provides a unifying look to their garden beds, but that’s not the reason you need it. Mulch, when done right, provides an insulating layer that protects your plants from extreme weather, keeps the soil from drying out, and provides nutrition back to your beds as it decomposes. It’s a lot of work to get mulch into place, so it can be frustrating to view it as temporary. But mulch breaks down—it's supposed to. A lot of people complain about their mulch blowing away, but fortunately this is a solvable problem. 

The right way to mulch

The surface of your soil is vulnerable. It is exposed to the sun and can easily dry out. It’s exposed to the wind, which can blow it away if you don’t have plant roots anchoring it. We are now experiencing extreme weather conditions all the time, including heat domes in summer and extreme ice in the winter, all of which wreak havoc on your plants. A healthy layer of three to six inches of mulch can really make a difference.

You want to ensure that this organic material you choose is pulled away from the stems of your plants. (Mulch shouldn’t be up against tree trunks, either.) You want your plants to be planted into the soil, not the mulch, and each plant has a natural place it should be buried up to in the soil, as it comes from the nursery or grows naturally, and the mulch would smother the plants. Pulling the mulch away creates a well around the base of plants, which is perfect for watering. 

Heftier mulch won’t blow away

Big box stores tend to sell bagged, dyed mulch. This mulch has three issues that make it a poor choice: the dye itself, which fades and adds a chemical to your beds; the lack of nutrition in it; and finally, people don't put enough of it down, and a light layer isn’t going to do much. This dyed mulch can look great at first, but again, that’s not the purpose of mulch, and the dye quickly gets bleached out anyway.Sometimes, people put down plastic before the mulch or landscape fabric, and this, too, is unadvised. The plastic will break down; it does not usually suppress weeds as well as you’d think; and it introduces microplastics to your beds. Getting rid of that plastic by taking it back up is a miserable process, too. 

Instead, you want natural material to sit on top of your soil, and you want a hefty amount of it—ideally, three to six inches deep. I like to use wood chips because they have weight to them, create a uniform look, decompose slowly and are spectacular for the soil as they compost. They’re also free—I use ChipDrop to get them yearly and have been using them for 10 years without much issue. You can also use straw (not hay—there’s an important distinction), or leaves. In the fall, rake or blow your leaves into your beds instead of bagging them. Leaf mulch becomes amazing compost while supporting local beneficial insects as a place to nest over winter. Using a heftier amount of mulch, and heftier mulch, means it is less likely to blow away. Even if some of it does, you still have a substantial amount of it. 

You may only think your mulch is blowing away

Mulch, when done right, decomposes in place, enriching the soil. It may be simply that what looks like disappearing mulch is really this process taking place. It can also be that it’s your dyed mulch losing color. You could also be washing the mulch away, if you water overhead instead of watering your plants at the soil line via drip irrigation.

Even if your mulch migrates, while your plant beds are now more exposed, it’s not really a problem for the places the mulch migrates to. It should just break down there, as well. The bigger issue is that your beds are left exposed to the elements and you lose the benefit. 

How to keep your beds tidier

Curbing or edging your beds can help mulch stay in place and keep your beds looking uniform, whether you use plastic or metal or bricks.  If you have a well-planted garden, the wind should be screened by your landscaping, as you want a healthy mix of understory, shrubs and then a canopy layer of trees. If you experience enough wind to be a problem for your mulch, you might consider that your landscaping has left your plants too exposed and introduce more of these layers. You can also consider ground cover, which is, hands down, the best way to reduce erosion, since it introduces roots to anchor the soil. I am reluctant to mention mulch glue, because I think it’s unnecessary, but there usually isn’t anything problematic in the glue itself. It’s a mix of bark dust and other wood products that are heated into a sticky adhesive you can spray onto your mulch to keep it in place. However, I fear it prevents the mulch from doing the thing we ask of it, which is to break down into compost. 

Mulch isn't permanent

Mulch is a to-do item you should address yearly. Choose the right kind of mulch, and make sure you are applying enough of it in the right places, and replace it when you see it disappearing. Occasionally, take a peek at the soil below your composting mulch. It’s likely to be a healthy layer of humus full of happy worms and mycorrhizae.