I’m on a bit of a tomato kick at the moment because I have quite a few growing happily in my tomato garden. I love growing tomatoes over the warmer months and find them fairly easy. But, should you mulch tomatoes?
My answer is a resounding yes! Why, I hear you ask? Well, tomatoes are fairly thirsty plants and mulching them helps to conserve water and stops it from evaporating too quickly when the hot summer sun is blazing down on the soil.
I wrote a comprehensive article a while back on the benefits of mulching that you might want to read.
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While I think mulch is important and beneficial for almost all the plants in the garden, how and what you use will vary for the types of plants that you’re growing.
Enjoy The Benefits Of Mulching When Growing Tomato Plants

There are numerous benefits to mulching your tomato plants and I’m going to discuss the most important ones.
Mulch Helps To Conserve Soil Moisture
The mulch that you apply around the base of the plant, helps to cover the soil. This means that it’s not exposed directly to the sun so moisture will evaporate at a much slower rate.
Mulch will also help to keep the soil a little cooler. This, in turn, slows down moisture evaporation.
This is particularly important for healthy tomato plants and lots of juicy ripe fruits. Tomatoes are thirsty plants and the more moisture that you can hold in the soil, the better for the healthy growth of your tomatoes.
The Mulch Will Aid In Weed Suppression
This year, I decided to use pea straw mulch on all of my vegetable beds and this has been highly effective in stopping any weed growth from coming through.
Why do you want to stop weeds from growing among your tomatoes? Quite simply, the weeds will compete with your plants for both water and nutrients. So, having the area completely weed-free is highly advantageous.
How does mulch prevent weeds from growing? You may or may not be aware that many weed seeds can stay dormant in the soil for years and years. Then, when conditions are right, they germinate and grow.
But, when the mulch covers the soil, it stops the sunlight from getting through. This basically inhibits the weed seeds from germinating in the first place.
Mulch Can Help To Keep Your Plants Disease Free
A lot of fungal or foliar diseases that affect tomato plants, like early blight, will overwinter in the soil. If the ground is bare and without mulch protection, the fungal spores can easily splash onto the lower leaves of your plants and take hold.
However, the mulch provides a barrier between the soil and your plants and stops this from happening. This is especially good news for sustainable gardeners like myself because I don’t like using chemicals on my edible plants to treat diseases.
The Mulch Can Protect Your Fruit
Another thing that mulch is good for is that it will protect the fruit that grows low on your vines.
Essentially, you don’t want any of those ripening fruits sitting directly on the soil. This will only cause them to rot before you’ve had a chance to harvest them.
The Mulch Will Add Nutrients To Feed Your Tomatoes
Over time, the mulch that you use around the base of your tomato plants will break down and add valuable nutrients to the soil. Apart from being thirsty plants, tomatoes are also heavy feeders.
So, unless you’ve prepared your vegetable garden well before planting by adding copious amounts of organic matter or perfectly aged compost from your compost pile, you’re going to have to provide additional nutrients.
The mulch you use can help with this but you have to select the right type of mulch if you want faster results. That’s why I prefer to use straw mulch because it’s already dry and will break down much faster.
I also prefer to use organic material rather than inorganic mulch because I’m always conscious of contributing to the health of the soil.
Mulch Will Help To Insulate Your Soil
Remember how I said that the mulch will help to keep your soil cooler when the sun’s blazing in the sky? Well, the reverse is true as well, especially as the weather starts to cool down again. You probably understand that tomatoes prefer warm soil.
A decent layer of mulch will help to insulate the soil, regulate the soil temperature and stop it from cooling down too quickly. This is especially important if you experience a cool spell during the warm growing season.
Or, if it’s heading towards the end of the season and you still have some tomatoes waiting to ripen. The mulch will help to keep the ground a little warmer as it works like a blanket over the soil.
What Mulches Are Best For Tomato Plants?

I’m going to write a more comprehensive article on the different types of mulch to use around productive tomato plants and why, but for now, let’s have a look at the different types of mulches you could consider using.
The types of mulches you could consider include:
- Straw mulch like pea straw or wheat straw
- Pine needles
- Dry grass clippings
- Dry shredded leaves
- Wood chips or bark chips
- Fine wood mulch that is well-aged
- Black plastic mulch sheeting
- Landscape fabric
Many of these types of mulch offer a range of benefits to your garden but for tomatoes, I do prefer to use straw mulch. It’s one of the best mulches for tomatoes because it’s fairly inexpensive, easy to lay and breaks down relatively quickly.
How Much Mulch Should You Use?

For tomato plants, I generally like to place a layer of mulch that’s around 2 to 3 inches (3 to 8 cm) thick. This will give you the best results because it’s thick enough to get all the benefits but not too thick to stop water from draining through into the soil below.
When watering your tomato plants, you want to ensure that you periodically check the soil under the mulch to ensure that it’s damp.
On the other hand, you might want to consider using soaker hoses and actually lay these under the mulch. This ensures that the water is getting to the shallow roots of your plants.
Frequently Asked Questions
Yes, you can use grass clippings but make sure that they are completely dry and that the lawn has not been treated with a broadleaf herbicide within the past couple of months.
If you’re using easily compostable mulches such as straw, these will usually take around 1 to 2 years to break down. I find that I will always replenish the straw mulches in my vegetable garden beds each growing season.
It’s not necessary to remove the old mulch. In fact, it’s much more beneficial to leave it so that it can break down and add nutrients to the soil. It will also help to improve the soil structure. You can just lay new mulch over the top after breaking up the existing mulch a little.
Final Thoughts
Adding mulch around your tomato plants is definitely a good idea and one I would recommend. It helps to keep the soil cool in the heat of summer and conserves moisture. This moisture retention means that you have to water less often.
Mulch also protects your plants from fungal diseases and keeps the fruit nice and clean. Plus, it adds nutrients to the soil and improves the structure as it breaks down.