10+ Tips to Successfully Mulch Your Vegetable Garden
You’ve dug, hauled soil, added compost, and finally planted your garden.
Carefully, you lined up your radish seeds and planted some tomato plants. Beans, squash, turnips! All your favorites are in the ground, you watered everything nicely, and now you need to wait a few days.
But now look! Where did your garden go?
That used to be my garden before I discovered the power of mulch.
Mulch has reduced my weeding to minutes a week, improved my soil, and grown more vegetables. Mulch conserves moisture and lowers soil temperature, too.
And it’s not complicated.
Perhaps you’ve thought about mulching, but you’re confused. You’ve heard cardboard may contain dangerous chemicals, bark leaches nitrogen from your soil, and hay contains weed seeds.
I’m here to answer your questions.
First, you may wonder, “What is mulch?”
“Are there disadvantages to using mulch?” is another frequent question.
And finally, “How do I mulch?”.
What is mulch?
Mulch is any material used as a covering for bare soil. The preferred material is natural and biodegradable.—Farmer Cindy
5 tips (and reasons why) to successfully mulch your garden
1. Use organic materials to mulch your garden.
The best mulch I’ve found is shredded dry leaves. They’re free, and by the end of the growing season, they will have decomposed and provided organic matter for your soil.
Choose materials as free of weed seeds as possible. So, for instance, don’t shred weeds and use them for mulch. Instead, they should go directly into your thermophilic (heat-producing) compost pile.
Weeds that fall into the most difficult to eradicate category—things like Johnson and Bermuda grass and bindweed; here in Texas, I throw in the trash or burn pile. No chances with those guys!
2. Shredded bark chips are fine and often free.
You may have heard that wood products will take nitrogen from your soil. That is true—but only if you mix them into the soil. If they are only on top of the ground, nitrogen loss will be minimal.
If you can, allow fresh chips to age for a year or two before using so that they will begin to decompose.
Don’t use dyed wood products.
If you can get chips directly from an arborist, it’s best because you won’t have to worry as much about trash mixed into the chips—contact tree care companies in your area. If you have room for them to dump a whole truckload, you can probably get them free.
3. Yes, corrugated cardboard is safe in your vegetable garden.
I spent hours investigating whether there are harmful chemicals present in the cardboard we’re likely to have in our homes. I was surprised that nobody seemed to have researched the question.
The usual answer is that only the printing inks on glossy cartons and the waxy surface of others are a problem when decomposing products.
A guide published by the UK-based Association for Organics Recycling states the apparent concern. “Co-mingled or not pre-sorted paper and cardboard is likely to include plastic from over-packaged cardboard, steel from staples, and certain adhesives.”
I recycle all my paper and cardboard, except for register tapes and gift packing paper. I thoroughly soak packaging such as ice cream cartons, tear them flat, and place them in my earthworm bed. In a few weeks, all that’s left is a thin layer of plastic to be thrown away.
All small pieces go to the worms, and large parts are laid flat and covered with bark chips in paths and under new planting beds. Each year, if weeds poke through, I add more cardboard and mulch.
Wet large pieces of cardboard when you lay them down and remove all plastic tape or staples. That’s all you need to do.
4. Clean straw can be good—IF it’s grown without certain herbicides.
And if it’s free of too many weed seeds. Those are two very big IFs these days.
Straw is the stalks and leaves left after harvesting grain, usually barley, rice, rye, or wheat.
It is different from hay, grass, or legume grown for livestock feed.
Hay is usually green in color, while straw will be yellow.
Dry grass clippings can be an effective mulch if they do not contain grass seeds and are not from invasive grass like Bermuda.
The problem with many of these products is herbicide residue. Unfortunately, you can also get enough residue to stunt your vegetables from the manure of animals fed herbicide-treated forage.
You MUST know what type of herbicide, if any, was used on the hay or straw.
You need to ask if picloram, clopyralid, or aminopyralid have been used on the fields.
Common brand names for the products include:
Pasture and hayfields: Curtail (2,4-D + clopyralid) , Forefront (aminopyralid + 2,4-D), GrazonNext (aminopyralid + 2,4-D), Grazon P + D (picloram + 2,4-D), Milestone (aminopyralid), Redeem R&P (triclopyr + clopyralid), Surmount (picloram + fluroxypyr)
Commercial turf and lawns: Confront (triclopyr + clopyralid), Lontrel (clopyralid), Millennium Ultra Plus (MSMA + 2,4-D + clopyralid + dicamba), Millennium Ultra and Ultra 2 (2,4-D clopyralid + dicamba)
Commercial vegetables and fruits: Clopyr AG (clopyralid), Stinger (clopyralid)
This list is from the North Carolina Extension Service
If you can’t determine the answer, don’t use the straw, hay, or grass in your garden. These herbicides kill weeds in the fields, but the residue can stunt your garden for years to come.
If you purchase only organically produced materials, you won’t need to worry about herbicides.
Likewise, manure from organically fed livestock will be safe, too.
5. Miscellaneous materials like compost, manure, rice hulls, and pine straw can be used.
Mix compost and manure into your soil; it’s too valuable to use as mulch.
However, I’ve used cottonseed hulls, old beanstalks, and even dead lettuce plants when I was desperate to cover the soil.
If it doesn’t spread weed seeds, it will lay flat and not blow away—you can use nearly any organic material as a mulch.
5 potential problems with using mulch
It can be hard to find enough suitable mulch at reasonable prices.
Yes, you can buy bagged shredded bark at any nursery or big box store, but that's pricey if you have a big garden.
Placing flat, wet cardboard on the soil and covering it with other materials will let you use less mulch.
It is tough to find enough organic material to mulch on more than a quarter of an acre of garden—however, alternatives such as mowing cover crops are left in place for mulch.
On our farm, we resorted to plastic, unfortunately. In Texas, conserving water is critical, so we used plastic mulch. However, it’s made of post-recycled plastic, which cannot be recycled again. It ends up in the landfill and is a huge chore to roll up at the end of its lifespan. I don’t suggest it for home gardeners.
2. Mulch can prevent your soil from warming up in the spring.
If you live in a cold spring area, rake the mulch aside and let your soil dry and warm. Then, as the weather gets hotter, rake it back, closer to your plants.
However, mulch will help retain heat in the soil to prolong your growing season in the fall.
3. Mulch can look messy.
Yes, if you have sheets of cardboard laid haphazardly and not covered with mulch, your garden will not be a showpiece. But if production is your goal, do your best with what you have.
Mulch can look nice and far better than caked soil with untidy weeds poking up everywhere in public areas where appearance is a concern.
4. It can be challenging to water plants under mulch.
If you garden in a climate that requires irrigation, one of the best investments you can make is a drip system you install before you mulch. Drip provides a slow, steady moisture source and cuts back on weeds, too.
It can be difficult to water through cardboard, so I only use large pieces in the pathways and under the vines of rambling plants, such as watermelon.
You can still run a sprinkler on a mulched garden or walk from plant to plant, watering with no problem.
5. Mulching takes a lot of time.
Not compared to weeding! Once a person has put their mulch down for the season, if you’ve used at least two to four inches of material and have it tucked up close to your plants, you’ll have very few weeds to pull.
You’ll spend less time watering since the mulch prevents evaporation.
However, you will spend more time harvesting! With the right mulch, properly applied—you’ll have more vegetables to pick, it’s true.
How to properly apply mulch.
Use fine-textured material such as ground leaves or fine bark mulch close to your small plants. Without light, plants won’t be able to grow, so the goal is to deprive the weed seedlings of sunshine.
Save cardboard or paper to use under coarser materials at least two inches from your vegetables, especially when the plants are small. You don’t want the mulch to shift and smother your crops.
Two to four inches is plenty if you apply it to bare ground.
It would not be enough to smother the weeds in the photo at the top of this article. That plot would need to be cultivated to kill the weeds and then be mulched.
4. For great results, use the stale bed technique.
The stale bed technique is a simple weed management tactic that generally involves four steps before mulching.
Prepare a seedbed,
weed seeds in the shallow soil zone germinate naturally, or after irrigation,
baby weeds are then killed with minimum soil disturbance as necessary, and
the crop is promptly seeded or transplanted into mostly weed-free soil.
Mulch your rows immediately, and the only weeds you’ll have are the ones that pop up close to your seeds or plants.
Even if you don’t use mulch, this method will help you drastically reduce weeds.
I’m a big believer in the benefits of mulch. And I’d rather have less weeding.
Since seeing how to do something is helpful, here’s a short video by expert gardener Joe Lamp’l, also known as Joe Gardener. I love his website, podcasts, and videos and 100% trust his organically-based advice.
Questions I didn’t answer?
Comments? Suggestions based on your experience?
Get in touch! I never get tired of talking about growing vegetables.
Thanks for reading!