Are you wondering whether or not you should mulch your tomatoes and if so, what material to use?
There’s no shortage of mulch options out there for your garden beds, but finding the right one for your tomatoes can make all the difference between a struggling crop and a bountiful harvest.
Mulching your tomatoes can serve a variety of different purposes. It keeps the soil warm when the weather turns cool and cool when the sun beats down.
It locks in moisture, keeps weeds in check, improves soil quality, and even helps prevent disease.
But not all mulch is created equal – and some options might be better suited for your growing conditions or gardening goals than others.
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In this guide, we’ll walk you through the best mulch options for tomatoes so you can pick the right one for your setup.
If you need a refresher about cultivating these nightshades in your veggie garden, check out our guide to growing tomatoes.
Now here’s a look at our list of the seven best mulches for your plants:
7 of the Best Mulches for Tomatoes
1. Compost
Compost offers many of the same benefits as the black plastic that’s sometimes used to cover the ground – without introducing microplastics into your soil.
The dark color helps absorb sunlight and warm the soil, which can be especially useful early in the growing season.
In areas where temperatures cool off at night, compost retains heat absorbed during the day, keeping the soil warmer overnight.
However, be aware that in hot summer weather that same dark color can intensify the heat. If that’s a concern, consider switching to a lighter material as the weather heats up.
You can buy compost or make your own. If you’re not composting yet, this might be the perfect time to start. Our guide to getting started with compost can help you out.
For gardeners who prefer to purchase, compost is often available from local municipalities, nurseries, garden centers, or online.
Need an online option?
Pick up a one-cubic foot bag of Tank’s Organic Compost available at Arbico Organics.
2. Grass Clippings
If you are a creative and thrifty gardener who favors reuse over buying new, you may be wondering if you can use grass clippings from the lawn to mulch tomatoes?
You can indeed!
Just be sure to apply the clippings in a thin layer. A thick pile can form a dense mat that prevents water and air from reaching the soil.
But more critical than how much you use is where those clippings came from.
If your lawn has been treated with broadleaf herbicides, skip this option entirely – the residues can damage or kill tomato plants.
If you have access to unsprayed grass clippings, they will make an excellent ground covering that will biodegrade over winter, becoming a source of organic matter in your garden soil.
But if grass clippings aren’t going to work in your garden, there are other solutions.
3. Living Mulch
Have you considered growing other plants as a ground cover instead of spreading organical material under your tomatoes?
Low-growing flowering plants can be used as living mulches for your tomato crop – and this is one of the many benefits of companion planting.
In addition to covering the soil, living mulch provides food and habitat for beneficial insects and pollinators.
There aren’t any major downsides to this strategy, as long as you choose your ground cover wisely.
Make sure to pick plants that thrive in the same growing conditions as tomatoes and stay low to the ground, options include sweet alyssum or nasturtiums.
‘Tiny Tim’ is a low-growing sweet alyssum with white flowers, perfect for use as a ground cover under your nightshades.
You can find packets of ‘Tiny Tim’ sweet alyssum seeds from Botanical Interests.
Perennials like thyme also work well. Thyme helps to repel pests and forms a dense mat beneath your tomatoes, serving double duty as mulch and companion plant.
You can find packets of thyme seeds in a variety of sizes available from High Mowing Organic Seeds.
4. Pine Straw
Pine straw isn’t just for flower beds and natural areas – if you have an abundance on hand, it can also serve as mulch for tomato plants.
Before buying a bale expressly for this purpose, keep in mind that pine straw breaks down more slowly than many other mulches.
You’ll likely need to rake it aside when prepping the garden again next season.
Also, pine straw has an acidic pH, making it ideal for acid-loving plants like blueberries. But if your garden soil is already on the acidic side, you might prefer to reach for another option.
5. Leaf Litter
When trees drop their leaves in autumn, these add humus to the forest floor and provide habitat for overwintering insects. As they decompose, the leaves add nutrients to the soil.
Maybe you’re already doing your part by letting those fallen leaves stay put through the winter to support the ecosystem.
If so, pat yourself on the back – and then keep an eye out for the bags your neighbors set out after raking.
Leaves are one of the easiest to source and cheapest materials you can use to cover the soil.
Simply gather and save them in the fall, then apply as a mulch in the spring or early summer when your tomatoes are in the ground.
There’s no need to shred them first, but as with grass clippings, be sure to apply them in a thin layer to avoid creating a thick mat on the surface of the soil.
Unlike pine straw, leaf litter can break down in place, gradually adding organic matter to your soil.
Learn more about using leaves for compost and mulch.
6. Straw
Straw is a lightweight, easy-to-spread mulch option for mulching tomatoes.
Since it’s light in color it will reflect the sun, helping to protect your crop from excessive heat during the height of summer.
You’ll need to apply a thicker layer of straw than you would with leaf litter or grass clippings to ensure it doesn’t blow away at the first gust of wind.
Also, be aware of potential biocide contamination. If the straw has been treated with herbicides or other chemicals, it could harm your plants.
Choose organic straw when possible, or ask whether it’s been sprayed or not before use.
Our guide to mulching with straw has more information.
7. Wood Chips
Finally, if you’re wondering if a bag of pine bark would work to cover the soil, here’s a better option: wood chips.
They’re more economical and environmentally friendly than bagged bark, especially if you make them yourself from tree and shrub trimmings using a chipper.
Or talk to a local arborist – many are happy to drop off a truckload of wood chips at no cost.
Smaller wood chips will biodegrade and become part of the organic matter in your soil, while larger chunks that don’t break down over winter may need to be pushed aside before planting the following spring.
As always, if the wood chips aren’t coming from your own property, ask whether the material has been treated with herbicides or pesticides.
Avoiding pesticide residues is just as important as steering clear of herbicides – after all, bees help pollinate tomato flowers!
Which Mulch for Your ‘Maters?
You now have seven different mulches to choose from for your tomato crop.
Make your choice based on your locally available resources, budget, climate needs, and personal preferences.
Which type are you using? Do you have a go-to mulch that we didn’t cover here? Drop your questions and tips into the comments section below!
And if you need more advice about growing a delicious harvest of tomatoes, have a read of these guides next:
