The Best Mulch for Your Vegetable Garden

I’ve become a bit of a mulch evangelist.

It started with my discovery of Ruth Stout all those years ago and has progressed into a full blown obsession.

Now I find myself blathering on about mulch in almost every gardening conversation I have. 

Nothing else has impacted my soil health and fertility as much as mulch.

And while results won’t happen overnight, I’m continually blown away at the improvements that come faster than I expected.

My mulched soil is softer, crumblier, and is filled with happy worms– just like nature intended. 

Mulch vs. Bare Dirt: Why It Matters

Stop what you’re doing. Close your eyes and picture the quintessential vegetable garden in your mind. 

Odds are, you pictured tidy rows of cabbages and carrots nestled into rows of clean, black dirt.

It’s beautiful… but is it what our gardens really want?

Where in nature do we see plants growing obediently surrounded by bare soil?

We don’t. 

The only place we see bare soil in nature is in a) industrial monoculture farms or b) deserts… neither of which is a good example of soil fertility. 

Nature doesn’t like to be naked. When we leave the ground bare, she’ll dutifully cover it with weeds. 

There’s the first benefit: Properly applied mulch drastically reduces weed growth. It won’t eliminate it entirely, but it can easily reduce it by at least 80%. 

For most of us, that’s reason enough. But just in case you need a bit more convincing….

You’ll water less. Not only does mulch capture water and prevent run-off during heavy rain, it keeps the ground cool in harsh midday sun and maintains soil moisture.

And finally, perhaps my favorite benefit of all: it feeds your soil. Mulches add organic matter to the soil, feed microbes, reduce soil erosion and compaction, and create a much happier ecosystem. After repeated years of mulch, my soil health, texture, and fertility only continues to improve. When we feed the soil, we bring our gardens into balance.

The Million Dollar Question: Which Mulch is Best?

And like any good question, the answer to is, “It depends…”

It depends on your area, your garden, your climate, but perhaps most importantly, the materials you have available will be the biggest limiting factor. 

You’ll need a lot of mulch– more than you think you will. A thin layer sprinkled across the soil won’t do…. plan on covering the soil with a 6-8″ mulch layer at least. 

I’ll share the different mulches I’ve used, starting with my favorite.

The Best Mulches for Your Vegetable Garden

Grass Clippings

Grass clippings are the darling of my vegetable beds and make excellent mulch. Plus they’re one of the easiest sources of free mulch. Considering we live on a high plains grassland, we have plenty of clippings, even though our animals graze the bulk of our acreage. 

I collect grass clippings throughout the summer and keep them in a bin made from pallets. We often use them as fast as we can mow. (And if I have leftovers at the end of the season, they overwinter nicely and I use them in the early spring.)

A few considerations before you use grass clipping as mulch:

• If the grass you’re cutting has been sprayed or treated with herbicides or pesticides of any kind, don’t use it. It’s not worth the risk.
• If you’re cutting a weedy, overgrown lawn with lots of plants that have seed heads, don’t use those clippings.
• After they sit for a while, clippings will get slimy during the early stages of decomposition. I’ve used clippings in all stages (even the slimy ones) and have had no issues.
• Grass clippings also heat up if they sit in a thick enough layer. I don’t worry about this too much, but if you have a hefty layer of mulch that’s touching a young plant, it *could* burn the plant. (Although I’ve never this happen.)
• Grass clippings seem to break down slightly faster than other mulches. But I don’t mind reapplying a fresh layer of mulch as needed through the year. 

Hay or Straw

First off, a quick clarification:

Hay is grass that has been cut & dried so it can be saved and fed to animals later in the year.

Straw is the dry stem left after grain (like wheat) is harvested. 

I’ve used hay for years but have recently mostly stopped using it to one major issue:

Many hayfields have been sprayed with persistent herbicides that will wreak havoc on your garden.

I’ve dealt with this not once, but twice, and I can assure you– it’s not worth the risk. 

Learn More About My Herbicide Mis-Adventures Here:

• I Think I Poisoned My Garden (the first time it happened)
• Your Compost May Be KILLING Your Garden…Here’s How to Fix It (the second time it happened)
• How to Fix Tainted Soil (how to handle persistent herbicide contamination if you already have it)

For this reason, I only use hay when I’m absolutely sure it hasn’t been sprayed. 

That said, IF you can find it, hay makes a fabulous mulch and I used it for many years. 

Straw performs similar to hay and its less common for it to be sprayed with herbicides that will persist in your home garden.

HOWEVER. Of all the mulch materials I’ve used, straw has introduced the most unwanted seeds into my garden, even when I apply a thick layer or let my chickens pick through it first. I still use straw if it’s all that I have available, but I expect to deal with a crop of wheatgrass the following year. 

A Note About Seeds:

When I talk about using hay in your garden, people lose their minds online and start yelling about weed seeds. Yes, it can happen. But after years using hay as mulch, you can avoid most issues by using a thick layer of mulch and reapplying 2-3 times throughout the growing season. This snuffs out hay seeds so the majority can’t germinate.

Cover Crops

I’m including cover crops on my list because I’m gravitating towards them more and more. While not technically mulch, when I use the “chop and drop” technique in my garden, the remaining root mass acts as a mulch of sorts, plus I often use the trimmings over the top of the soil.

Covers provide many of the same benefits to garden soil (improved soil structure, more organic matter, reduced weeds) so they’re worth looking into.

Here’s more info on how I use covers in my garden:

• Why You Should Plant Cover Crops In Your Garden (blog article)
• Cover Crops: Your Garden’s Best Kept Secret (podcast episode)
• Planting Cover Crops (video)

Compost

Most gardeners use compost as a top dressing but if you use a thick layer, it can also act as mulch. (Charles Dowding has popularized this method via his books and YT channel.)

The kicker is that you must use quality compost for this work (aka evenly decomposed and free of large clumps.)

Properly-made compost will add nutrients and organic matter to your garden more quickly than other materials. 

Unfortunately, I don’t make enough compost to use it as mulch. And my aged manure pile is Russian Roulette when it comes to herbicide contamination, so unfortunately I can’t add it to my soil as a top dressing or otherwise. 

If you plan to use compost, start with a generous layer (3 to 6 inches) and be ready to add more throughout the growing season. Learn how to make your own compost here.

Shredded Leaves

I’ve never personally used leaves as mulch since:

A: Trees are few and far between on the prairie, and,

B: Our hurricane force winds tend to blow any leaves I *do* have into Nebraska before I can collect them. 

That said, if you live in a leafy place, dry leaves are wonderful mulch and don’t come with the same herbicide concerns as grass clippings, hay, or straw. It’s best to shred them first so they don’t create too much of a “mat” on the soil. A lawn mower, weed whacker, or electric leaf muncher works for this.

My assistant Cris (if you’ve ever emailed me, you likely chatted with her!) uses shredded leaves as a mulch every year (she lives in a different state than me and has plenty of trees on her property). During the fall season, she finely shreds the leaves (she has found that if you keep the leaves whole, the moisture levels are uneven in the beds and the leaves are more prone to fly away in a strong wind) and tops off all of her garden beds with a thick layer of shredded leaves. This not only helps clean up the beds before winter, but prevents weeds from seeding during the dormant seasons.

Pine Needles

If you have an abundance of pine trees, use ’em. Considering my pesky lack of trees and accompanying lack of pine needles, so I don’t have much personal experience here. The most common concern with pine needles is that they are too acidic (Fresh pine needles have a pH of roughly 3.5). That said, the acidity will decrease as the needles decompose and dry (once they dry, they are called ‘pine straw’) and if you’re not digging the fresh needles into your soil, this is even less of a concern. A 2 to 3 inch layer of pine straw should suffice.

In addition to leaves, my assistant Cris also uses pine straw in her gardens. The main issues she has with pine straw is that the needles are sharp and poky which can be a minor annoyance. Also, it decomposes much slower than shredded leaves.

If you’re hoping to use a mulch that will slowly add organic matter to your garden beds, choose shredded leaves over pine straw. 

Wood Chips

Wood chips make an aesthetically pleasing mulch and I feel like most vegetable gardeners love the idea of wood chips.

However they are the LAST option I’d choose for my vegetable plants. Here’s why:

Wood mulches are a high carbon material. In order for wood chips to decompose, they need nitrogen, and lots of it. 

But your plants also need a lot of nitrogen. And if the nitrogen in your soil is being tied up in decomposing the wood chips, it won’t go to your vegetables. 

Now… if the wood chips are laid on top of the soil, they won’t steal as much nitrogen. But if they are tilled or dug into the soil, you’re setting yourself up for problems.

So if you have perfect soil that will never need to be turned over or dug up in the future (this is the ideal for many of us, but it takes time and effort to get there), top-dressed wood chip mulch may be perfect for you.

BUT.

If you have transitional soil that needs to be lightly worked or broad forked in the spring, or you plant to till/dig your garden at any point in the future, wood chips will be a nightmare.

What About Back to Eden??

The Back to Eden method was pioneered by Paul Gautschi and his stunning gardens took the internet by storm a number of years ago. It’s a compelling system that combines “lasagna-style” garden layers with wood chip mulch and no-till for a garden that appears to operate as nature intended.

The Back to Eden Method in a Nutshell:

1. Cover the garden plot with at least 3 sheets of newspaper.
2. Cover with 3 to 4 inches of quality compost. 
3. Place 4 to 6 inches of wood chips on top of the compost. Choose smaller wood chips made from whole trees. (Note: some trees naturally contain elements that discourage plant growth, so be careful about what type of wood chips you use.)
4. Scrape back the top layer of wood chips when you’re ready to plant. 

While I talk to a ton of people who are romanced by the notion of Back to Eden, I’ve found FAR fewer folks who’ve actually done it successfully.

That’s not to say it won’t ever work (I believe it can), but you’re going to need an ideal situation. Otherwise, you’ll be dumping wood chips on one year and raking them off the next. 

I love an audacious homestead experiment, but this is one risk I’m not willing to take.

If you are still intrigued by Back to Eden, do your research and start with a small plot first. 

All that said, while I never use wood chip mulch for my vegetables, I do love it for my garden walkways or flower beds.

A Note About Slugs:

Slugs can be an issue with wood chip mulch. In fact, I brought them into my garden for the very first time but using wood chip mulch in my walkways… There are ways to combat slugs (staking plants off the ground, using diatomaceous earth, etc.) but if you can avoid the problem in the first place, it’s not a bad idea.

Fabric or Plastic “Mulch”

Inorganic materials, like black plastic or landscape fabric, are my last choices when it comes to garden mulch. 

First off, one of the biggest benefits of using natural materials is the organic matter it adds to soil as it breaks down. You won’t get that with fabric. 

• Plastic or fabric is another thing to BUY. Yes, you may need to purchase other mulch materials, but there are more avenues to find them for free.
• I hate plastic. I mean, sure, I use it around my homestead in various applications, but I don’t love it. And even if you reuse it year after year, it ultimately ends up in the trash.
• Plastic may solarize the soil. Sometimes this is a good thing. If you’re dealing with a hopelessly weedy area, laying black plastic over it in the spring (for several months) can cook weed seeds. But I wouldn’t use this method unless absolutely necessary, as it can also kill good soil life as well.

Last year I broke down and bought a couple rolls of landscape fabric and they were handy in the following places: 

• My long onion rows. We grew a ton of onions last year and keeping up with weeding on rows that are hundreds of feet long wasn’t happening. We laid out a strip of fabric and burnt holes where we planted the onion sets. It didn’t eliminate all the weeds, but it helped. 
• My flower beds. I’m spread pretty thin with garden chores in the summer, and my perennial flower beds are last on the list. I laid down fabric in the beds surrounding the house and covered them with wood chips. The beds stayed tidier and required less work from me. 

Regardless of what mulch type you choose, you’re making a positive step towards a more holistic garden. Mulch on, my friends!

Curious how to do the Deep Mulch method? Check out my other mulching posts:

• How to Use the Deep Mulch Method in Your Garden
• Deep Mulching the Garden Year One: An Update
• Our Deep Mulch Garden Year One: Final Wrap-Up
• Our Deep Mulch Garden — Year Two
• Deep Mulch Gardening FAQs