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Is Mushroom Compost Good For Tomatoes?

If you’ve ever tried to grow tomatoes, you know how frustrating it can be. Getting the soil right, the amount of water and light they need as well as making sure you use a fertilizer or plant food can be difficult.

Getting those nice, red ripe tomatoes is every gardener’s dream, whether you’re a pro or just beginning. And there are so many products on the market claiming to help you get your fruit looking (and tasting!) the best.

But is mushroom compost good for tomatoes? We have put together all the information to answer this gardeners’ dilemma once and for all!

What Do Tomatoes Need to Grow?

Tomatoes are often mistaken for a vegetable but they are in fact a fruit and need to be treated as such when you’re attempting to grow them.

Know the Type You Want

There are so many different varieties of tomatoes from the small, sweet cherry tomatoes to the huge beef tomatoes we use for burgers and sandwiches. But all of them can be grown in almost the same way.

Cherry Tomatoes

Transfer Seedlings

Tomato plants start off as seedlings, but when they have started to sprout and are around three or four inches tall and are starting to blossom, you should transfer them to larger pots (around nine inches in diameter) or even put them into a “growing bag”, which is a plastic bag of topsoil and compost mixture.

Tips as They Grow

Tomatoes Ripening In A Greenhouse

Tie the thick, main stem to a cane if it is a stalk-based plant but if it is a bush variety it will grow fine in a pot or hanging basket.

It should be watered regularly and fed every two weeks with a liquid fertilizer. Tomatoes like sunlight, so make sure they are inside a greenhouse or against a sunny wall or fence in your backyard so they can soak up at least five hours of daylight every day.

Problems with Growing Tomatoes

Annoyingly, tomatoes are prone to diseases and blight which makes growing them very tricky. There are a few common diseases you can identify and work to eradicate as soon as you see them appear.

Blossom End Rot

Blossom end rot, which shows up as dark blotches on the ends of the plant, is caused by not enough water. You should water your tomatoes regularly and never let the soil dry out completely. It can also be caused by a lack of calcium in the soil.

Tomato Blight

Tomato blight is also the scourge of the fruit farmer and it is where the wet weather causes fruit and leaves on the plant to rot prematurely. There are some strains of tomato plant that are resistant to this blight, so if you live in a particularly wet climate, then you should choose one of these types. You can also use a protective spray to save your plants.


Tomato leaf mold also causes loss of fruit and entire plants in greenhouses. This is where yellow patches show up on the leaves themselves. You can prevent this by making sure your growing area is really well ventilated and again there are crops that are resistant to this disease.

What is Mushroom Compost

Mushroom compost is just one of the ways you can add nutrients to your garden soil. It is made from a mixture of different things depending on where it is produced but mainly it has hay, straw, grains, peat moss, chicken manure and potash. It doesn’t actually use mushrooms (as you might have thought!) but it is called “mushroom compost” as it is used for growing the fungi. It takes around a month to produce and has been used for years in different mixtures to improve mushroom growth.

Mushroom Compost Material

Benefits of Mushroom Compost

Booster Juice

Mushroom compost can be really good for your vegetable garden and it is already being used for mushrooms, so it is a proven way to boost crops. Its main use is to make your soil hold water more easily, which means that using it with tomatoes is excellent because you don’t want your tomato plants to ever dry all the way out.

Increases Alkaline

Blossom End Rot - affects the bottom skin of a growing tomato fruit

It also raises the soils alkaline content and it is rich in calcium. Your tomato plants will be vulnerable to Blossom end rot if the level of calcium in the soil is not high enough, so getting this additive in there early will help protect your crop.

Added Protection

When you use mushroom compost to create a compost tea, it can be used to spray tomato plants to protect them from many bacteria and diseases. This is a natural way to protect your plant against things like leaf mold in some varieties.

Using Mushroom Compost

You can use mushroom compost just like you would use any other compost. Just mix it in with your potting soil in the tomato pots or even fill a grow bag with the compost and plant your tomatoes in that. The high water retention rates mean you don’t have to worry about your plants drying out if you don’t manage to water them every day and it also keeps the water level in the soil constant rather than flooding and then drying.


You might also enjoy reading about: Compost vs. Fertilizer

Create a Top Layer

You can also use mushroom compost on top of the soil to create a mulch layer which will also trap moisture and protect your plants and, as mentioned above, you can create a tea by dumping a trowel full of compost into a bucket of water and letting it stew for a day or two.

Bottom Line

So, the answer is yes, mushroom compost is good for your tomatoes and your vegetable garden. It is a cheap and easy way to help your fruit grow large and tasty.


The uses of mushroom compost are:

  • Trapping water in the soil to make sure it doesn’t dry out
  • Adding calcium to the soil which is vital for healthy tomato plants
  • Use it as a mulch to keep moisture in
  • Create a compost tea as a natural spray which protects against bacteria

So, the next time you want to grow tomatoes, get some mushroom compost and use it to make your plants strong, healthy and protected from disease. Did you find this information helpful? Did it answer all your questions about mushroom composting and growing tomatoes?  Feel free to comment and share below if you have any questions, concerns, or tips of your own!

You might be interested in how a composter works.

About The Author

Candace Osmond

Award Winning Designer, Candace Osmond has been in the industry for over a decade. She studied Interior Decorating & Design and is also an accomplished writer and multi-published author. When she's not typing away from the comforts of her desk, Candace can be found travelling to warm destinations, tending to her garden, or enjoying the outdoor haven that is her backyard. Candace currently resides in the breathtaking Maritimes of Eastern Canada with her husband, two beautiful kids and one slobbery bulldog.

  • Rose says:

    I question planting tomato plant directly in a bag of mushroom compost because I have read that it contains a high soluble salt (?) and therefore should be used sparingly?

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