Top 5 Mulches For Your Garden

Mulch is one of the best things you can add to your garden. It blocks weeds from growing. It can add organic matter or nutrients to your soil. Mulch helps keep moisture in your soil and prevent erosion. It can promote biodiversity in the soil web helping your plants fight off pests and disease. The list of potential benefits goes on and on. But there are a lot of different mulch options out there. Some work better than others. Some are much more expensive than others. How’s a gardener to know which are the best mulches for your garden? Here are my top five mulches and why they might work for you.

Best Mulch – Woodchips

I love woodchips because they tick a lot of the key boxes for mulches in your garden. They are great at blocking weeds, even in a relatively thin layer. Woodchips take a while to break down so you don’t have to reapply every few days or weeks. They do an excellent job of retaining moisture, preventing erosion, and adding organic matter and biodiversity to your soil. They can even score well on the cost scale if you are lucky enough to find a local tree service that has extra to give away.

You will need to avoid black walnut chips if you plan to put the mulch around some veggie crops (like tomatoes). Also, very fresh pine needles, chips, or bark can increase acidity in your soil, but it decreases as they break down. If you don’t have a local source of cheap or free woodchips, be careful when buying chip mulches in bags. Some of them can have weed killers added. This might be OK for mulching around ornamental trees, but can permanently damage your garden soil.

Runner Up – Livestock Bedding

Livestock bedding is the mulch I use the most in my garden, because I have a lot easily available. Hay or straw that has been pooped, peed, or just ground into the dirt by horses, cattle, poultry, rabbits, sheep, or goats can be a great mulch. It comes pre-fertilized, and also has begun to break down a little. Most of the seed heads are eaten by the livestock, so it’s relatively weed free. If you put down a 4-6 inch layer, it can provide excellent weed blocking and moisture retention. The manure mixed in provides nutrients and can add diversity to your soil micro-biome. Plus, the best thing in my opinion, it’s basically free. It’s a great way to reuse organic matter that would otherwise be wasted.

You should try to avoid any bedding from sick animals, or that has been treated in any way. If the manure is fresh (especially from poultry), you may need to let the mulch age a little before planting into it. The high ammonia content of fresh manure can burn the plants. We like to mulch our beds in the fall, after harvest time when they are empty. The mulch protects the soil over the winter and breaks down enough that it’s ready for planting in the spring. We add some more mulch in the late spring when transplanting seedlings. Especially for plants that need a lot of weed suppression, like tomatoes and peppers.

Close Third – Mulched Leaves or Grass Clippings

If you don’t have access to spent livestock feed or bedding, mulched leaves or grass clippings can be a great option. You will have to pile them on pretty thick because they break down more quickly than the first two mulch choices. However, a thick layer of leaves or grass can do a great job of blocking weeds and retaining moisture. They break down quickly providing a lot of organic matter for your soil and can introduce a lot of biodiversity, especially the leaves. If they come from your own yard, or nearby, they can be essentially free.

Again, avoiding leaves from the black walnut tree is key to avoid a toxic interaction with certain vegetables. Also, only apply grass clippings from a source you know doesn’t spray anything on their lawn. Some local municipalities provide free or low cost leaves or grass clippings collected as part of their spring and fall cleanup activities. In general, the more shredded they are, the faster they will break down. So if you plan to mulch over the winter, consider not shredding too much. But if you’re adding mulch during the growing season, you may want a finer cut.

Unconventional Choice – Shredded Paper

This option for mulch in your garden is more unconventional. If you don’t have access to woodchips, straw, leaves or grass, but do have a lot of paper, it can be a great option. The classic mulches in this category are shredded (or not) cardboard or newspaper, but other non-bleached, not glossy paper can work. Using cardboard, several thicknesses of full sheets, or a thick layer of shredded paper can effectively block weeds and retain moisture. It will break down over time, with cardboard taking the longest and shredded paper a much shorter time. Again, if you’re using paper products that you would otherwise discard or recycle, it can be a very cost-effective choice of mulches for your garden.

Avoid brightly colored papers or ink, plastic tape, and glossy coatings. Many newspapers print with soy-based inks that are biodegradable and won’t harm your garden. Cardboard mulch can also be great to use between your garden beds in the walkways, as it can take a while to break down. Some gardeners even use folded newspaper as biodegradable pots for seedlings and then plant them directly in the soil. There are lots of options if you have a good source of clean paper.

Easy but Expensive – Biodegradable Plastic

The last option in our top five list is biodegradable plastic mulch. These thin film plastics are usually made out of soy or corn oils and break down in a few weeks or months. The plastic can come in different colors, but most are black. Most are relatively easy and quick to spread over your garden beds, but having regularly sized beds can make it even easier. These mulches can do a great job of retaining moisture, and the dark colors can heat up your soil. This solarizing effect can kill weed seeds and give warm weather plants a great head start in the spring.

However, hot soil is not ideal, for some cool season plants like lettuces, broccoli, cabbage, and kale. The other downside of biodegradable plastic is the cost. They can get pretty expensive if you plan to cover a large area of your garden. If the plastic rips, the whole film can deteriorate quickly and it’s not as easy to patch as just dumping on more chips, straw, leaves, or paper. There are non-biodegradable options that are more durable, but unresolved issues about microplastics staying in the soil have kept them out of my garden for now.

Now that you have more info on my top five favorite mulches for your garden, which one is right for you and your garden? Do you have access to a lot of free organic matter like woodchips or leaves? Are there resources in your area that you can tap into? What happens to the grass clippings and leaf litter that gets collected in your neighborhood? Do some web research or make some phone calls and you might find a great source of mulches for your garden right in your own backyard. Good luck!

Want more info on the benefits of using mulch? Check out my post on How to Protect with Mulch and find out all the ways mulch can help your garden thrive.

Need a way to track your mulching schedule and document which options worked best for which plants? My Ultimate Garden Workbook is the best way to keep your garden info available and organized. Get your downloadable, printable copy today!