Can You Mulch Around Tomato Plants (8 Things You Can Use)

Mulch is great because it can suppress weeds and retain moisture in soil, among other things.  However, many gardeners wonder if mulch will kill tomato plants.

So, can you mulch around tomato plants?  You can mulch around tomato plants as long as the mulch does not touch the stems of your plants.  Mulching around tomato plants prevents weeds from growing and reduces the need for watering during hot weather. A layer of mulch 2 to 3 inches deep will be enough for tomato plants.

Of course, you will need to choose the proper mulching material, and you will need to apply it at the right time for the best results.  Let’s take a closer look at mulching around tomato plants, what you should use for mulch, how much you should use, and when you should use it.

Can You Mulch Around Tomato Plants?

You can mulch around tomato plants to provide protection from weeds, drought, and temperature changes.  However, you do need to be careful about what type of mulch you use, how much you use, and when you apply it.

When mulching around tomato plants, you need to choose a proper material, use the right amount, and apply it at the right time.

Before I talk you out of it, though, let’s take a look at the reasons why mulching around tomato plants is a good idea.

Why Mulch Tomatoes?

Mulching around your tomato plants has several important benefits that improve the health of plants and give them a better chance of survival, including:

  • Suppression Of Weeds
  • Moisture Retention In Soil
  • Insulation Against Temperature Changes
  • Reduced Fertilizer Leaching

Suppression Of Weeds

Mulching around your tomato plants will suppress weeds by preventing other seeds from growing.  As an added benefit, if you spread mulch over established weeds, it can smother them due to lack of sunlight and air.

Mulching can prevent the growth of weeds so that tomato plants do not need to compete with them.

With less competition from weeds, your tomato plants will have more water, nutrients, and sunlight. This means more energy to grow and produce lots of fruit for a good harvest.

Moisture Retention In Soil

Mulching around your tomato plants retains moisture in the soil.  This reduces the need for frequent watering during hot, dry weather.

When you do water your plants, mulch will prevent soil from splashing up onto the leaves and fruit.  This prevents the spread of soil-borne diseases that affect tomato plants. Mulching also avoids fruit rot for low-hanging fruit on tomato plants.

Insulation Against Temperature Changes

Mulching around tomato plants helps to insulate the soil against temperature changes.  This helps to avoid cold damage to tomato plants due to chilly nighttime temperatures.

It can also prevent the soil from heating up too much on a hot day.

Reduced Fertilizer Leaching

Finally, mulching around tomato plants reduces fertilizer leaching.  This means that you can fertilize less frequently, and also worry less about polluting local water.

For more information on mulching, check out this article from the University of Georgia Extension on mulching vegetables.

The best part about mulch is that it will eventually decompose, providing nutrients to the soil (it also provides organic material if you use compost, leaves, or other natural mulches).

Of course, the time it takes for mulch to decompose will depend on the material it is made from.

What Is The Best Mulch To Put Around Tomato Plants?

The best mulch to put around tomato plants may be something that you already have available in your yard for free!  Some good choices for mulch for tomato plants include:

  • Grass Clippings – these can come from your yard, a neighbor’s yard, or a landscaping company.  In addition to acting as mulch, grass clippings will provide lots of nitrogen to your garden when they decompose.  You can also turn grass clippings into compost before putting them in your garden.  For more information, check out my article on how to compost grass clippings.
  • Leaves – after a fall cleanup, there are lots of leaves around for the taking in your yard or nearby yards (just make sure to ask neighbors first!)  Leaves can be used whole or chopped up (as in a lawnmower) before using them as mulch.
  • Sawdust – if you know someone who runs a sawmill, or a carpenter who does lots of projects, then you can get some sawdust for your garden.  Sawdust contains lots of carbon, so it can tie up nitrogen if mixed into the soil.  Use it on top of the soil as mulch, or else turn it into compost first before mixing it into the soil.  For more information, check out my article on how to compost sawdust.
  • Newspaper – if you can get old newspapers from neighbors, you can use them to cover the ground around your tomato plants.  This will help to prevent weeds just like any other mulch.
  • Cardboard – similar to newspaper, cardboard will take a little longer to decompose, but it will still act as good mulch for your garden.  You can often find free cardboard boxes at Costco, BJ’s, and other wholesale clubs. Check out my article on uses of cardboard in the garden.
  • Wood Chips – this is what people often think of when they hear mulch.  Wood chips take a lot longer to decompose than grass or leaves, which is good if you don’t want to apply mulch often.  Cedar and cypress resist decay, so they last the longest of all.
  • Pine Needles – this is an option if you have pine trees on your property.  It is a good way to reuse the needles after you clean them up.
  • Compost – after composting yard waste and kitchen scraps, many gardeners mix compost into their garden soil.  This adds organic material to the soil, making clay soils drain better.  It also adds nutrients to the soil.  However, compost can be spread on top of the soil to act like any other mulch by suppressing weeds, retaining moisture, and insulating against temperature changes.  For more information, check out my article on compost versus mulch.
Grass clippings are a good choice for mulch, as long as they come from a lawn that was not treated with pesticides or herbicides.

Of course, there are a few things to avoid when choosing materials for mulching your tomato plants.  First of all, if you use wood chips as mulch, be sure to avoid painted wood chips.

If using grass clippings, make sure that the lawn they came from was not treated with pesticides or herbicides.  Otherwise, those chemicals can hurt your tomato plants or even end up in your food!

If you are using leaves, make sure to let them age for a while first.

Straw should be avoided for a couple of reasons.  First, straw may contain seeds that you do not want growing in your garden.

straw bale
Straw can delay the warming of soil in the spring, which is not good for warm-weather crops like tomatoes. Consider using something else as mulch!

Also, straw can slow the growth of warm season crops like tomatoes.  For more information, check out this article from the Michigan State University Extension on selecting mulches for your vegetable garden.

How Much Mulch For Tomatoes?

According to the Texas A&M University Extension, a layer of mulch 2 to 3 inches (5.1 to 7.6 centimeters) thick will be sufficient for mulching around tomato plants.

If you do decide to use straw, a thicker layer may be necessary to prevent weeds from growing.  If you mulch multiple times during the growing season, consider how much you have already put down (and how fast the straw is decomposing).

compost bin
Spread a 2 to 3 inch thick layer of mulch around your tomato plants. You can use chopped leaves (shown here) as one option for mulch.

If you already have a thick layer of mulch, you may not need any more, or you may only need another inch due to settling.  Remember that too much mulch can kill your plants, so don’t overdo it!

For more information, check out my article on how too much mulch can kill plants.

When To Mulch Tomato Plants

You should mulch tomato plants in the spring. However, be sure to wait until the soil warms up to mulch around your tomato plants.

Tomatoes need warm soil to grow – a soil temperature of about 70 degrees Fahrenheit (21.1 degrees Celsius) is ideal for growing tomato seedlings.

If you apply mulch when the soil is still cool, it will delay the warming of the soil due to sun and heat (since insulation works both ways!)  For more information, check out this article on growing tomatoes from the University of New Hampshire Extension.

How To Mulch Around Tomato Plants

Once you have chosen a type of mulch to use, be sure that you get it from a clean source (for example, grass clippings from a lawn grown without pesticides or herbicides).

Sawdust is one good option for mulching around tomato plants. Just make sure not to mix it into the soil, where it can tie up nitrogen and prevent plants from absorbing it.

Wait until the soil is warm enough for your tomato plants.  You should also water before mulching if the soil is dry.

Spread a layer of mulch 2 to 3 inches thick around your tomato plants.  Spread it as far as necessary to prevent weeds from growing anywhere near your plants, since this will prevent competition for resources.

Avoid the temptation to put mulch around the base (stem) of your tomato plants.  Leave the soil bare right near the tomato plant itself.

At the end of the season, you can work grass clippings or leaves into the soil, where they should decompose over time.  Wood chips will take longer to decompose, so you may want to leave them on the surface or put them in a compost pile to let them decompose.


Now you know that you can mulch around tomato plants safely, as long as you take the proper precautions.  This includes choosing the right mulch from a clean source and applying the proper amount at the proper time.

You might also want to read my article on mulch vs. soil.

I hope you found this article helpful – if so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!



Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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