As a gardener, you likely end up with a surplus of tomato plants at the end of each growing season. While some choose to throw them in the trash, composting tomato plants is a great way to recycle nutrients and improve your soil health. However, there are some important factors to consider before tossing old tomato plants in the compost bin. In this article, we’ll go over the pros and cons of composting tomatoes and provide tips for doing it successfully.
Why Compost Tomato Plants?
Composting is beneficial for several reasons:
- It reduces waste sent to landfills
- Recycles nutrients from the plants back into the soil
- Improves soil structure and moisture retention
- Attracts helpful organisms like earthworms
Composting tomatoes specifically adds organic matter and nutrients like nitrogen, phosphorus, and potassium to enrich garden beds.
As long as the plants are disease-free, most gardeners agree composting tomato plants is a smart way to reuse waste.
Risks of Composting Tomatoes
However, there are some potential risks to be aware of:
Can Spread Disease
Tomatoes are prone to fungal diseases like early blight, Septoria leaf spot, and fusarium and verticillium wilts. Bacterial diseases like bacterial spot and canker can also be issues.
If infected plants aren’t properly composted, these pathogens can survive and spread via compost. This is especially problematic in cool climates where fungi and bacteria persist through winter.
To avoid this, inspect plants closely and don’t compost any with signs of disease. Also, maintain high temperatures in your compost pile to kill pathogens.
May Not Decompose Completely
Large vines or whole plants may not break down fully in a compost pile. This can leave chunks of material in your finished compost.
Chopping plants into smaller pieces helps speed decomposition You can also compost just the leaves and stems while disposing of thicker vines
Could Spread Volunteers
Some tomato seeds can survive composting and sprout the following season. This isn’t necessarily bad, but volunteer plants in unwanted areas of your garden can be a nuisance.
Again, chopping plants helps destroy seeds. You can also hot compost tomatoes which uses higher temperatures to kill seeds.
Tips for Composting Tomato Plants
If you want to compost tomatoes. follow these tips
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Inspect for disease and only compost healthy plants.
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Wait for a dry day, then lay plants out to dry before composting.
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Chop or shred plants into smaller pieces to speed decomposition.
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Consider composting just the leaves/stems and disposing of thick vines.
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Layer plants with high-nitrogen materials like grass clippings.
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Turn and mix the pile frequently to aerate.
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Monitor temperature and moisture levels in the pile.
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Hot compost tomatoes to kill pathogens and seeds.
Can You Compost Tomato Plants with Diseases?
As mentioned, it’s risky to compost diseased tomato plants. Fungal and bacterial diseases can easily survive standard composting. However, plants with viral diseases like tobacco mosaic virus or cucumber mosaic virus are safer to compost.
The best practice is to identify and remove any diseased plants as soon as you notice an issue. Discard these in the trash rather than the compost pile.
If you’re unsure if a plant is diseased, play it safe and leave it out of the compost. Prevention starts with practices like crop rotation, staking, mulching, and drip irrigation to keep your tomatoes healthy.
Hot Composting Tomatoes
For worried gardeners, hot composting is a solution to kill pathogens and seeds on tomato plants.
To hot compost:
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Shred plants and combine with high-nitrogen “green” materials.
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Maintain a temperature between 130-170°F in the pile.
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Monitor temperature using a compost thermometer.
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Turn or stir the pile daily to distribute heat.
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Water as needed to keep the pile moist but not soaked.
After 4-6 weeks, the high temperatures should eliminate diseased organisms and seeds. You can then add the finished compost to your beds.
Other Uses for Tomato Plants
If you choose not to compost, here are other options:
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Add chopped plants to a worm composting bin for vermicompost.
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Use as a mulch around plants. Chop and lay a layer around beds.
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Bury vines and stems in empty garden beds to enrich the soil.
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Put in yard waste collection if your city offers this service.
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Burn dried plants as kindling for bonfires or fireplaces.
Composting tomato plants allows you to recycle nutrients, improve soil health, and reduce waste. However, take care to avoid spreading diseases and volunteer tomatoes in next year’s garden. Inspect plants, chop material, and maintain proper conditions in your compost pile. Hot composting is an option if disease is a concern. With some diligence, reusing tomato waste through composting is safe for your garden and the environment.
What Are the Risks?
It is true that composting tomato plants can be problematic. Many people would rather just throw away their plants and not do it at all because if they do it wrong, it can cause a lot of problems the next season.
When you compost these plants, there are a few things that could go wrong: diseases could spread, unwanted plants could grow, and the plant matter might not break down properly. Let’s take a look at each of these, followed by tips for managing your compost pile effectively.
Spreading disease is the most serious concern associated with composting these plants.
If pathogens in plant matter don’t get killed during the composting process, they can return to ruin crops the following season.
Many bacteria and fungi can live on plant matter in the middle of a compost pile that isn’t being managed properly. Late blight and early blight, for instance, can overwinter on vines that haven’t broken down completely.
In order to safely compost potentially diseased plants, it is crucial for the pile to be hot. This means consistent temperatures between 131 and 170°F.
Proper composting techniques are important, to ensure that plant material breaks down properly and pathogens are destroyed.
Some diseases, like fusarium wilt, verticillium wilt, and bacterial canker, can live through the composting process even if it is done right. For the most part, if you think your plants might be sick, it will be easier and faster to keep them out of the pile altogether.
Personally, I hate the idea of trashing plants.
Instead, I made a second pile far from my garden where I throw suspect tomato plants, weeds, grass, and any other viney plant matter that doesn’t break down easily or might be full of seeds I don’t want to plant.
If you have the space, I highly recommend creating a second pile with this designation. Just make sure to keep it out of the way and not put finished compost in your garden beds.
Volunteers in the Garden
If the fruits and vines are composted together, some seeds might make it through the winter. This could mean that seedlings appear in random places in the garden next spring.
I never put the fruit from the vines on my compost pile; I just throw them away. Since the seeds need to be killed, the compost pile must stay over 140°F for at least two weeks.
From some points of view, this could be a good thing: extra tomatoes that you didn’t have to work for!
But don’t get too excited.
You can get a good crop from tomatoes that grow on their own, but if you grow hybrid varieties, they might not bear any fruit at all. They may also have the potential to harbor pathogens that can spread to the rest of your crop.
It is usually best to get rid of tomato plants that aren’t supposed to be there, but sometimes I let a few grow because I’m curious.
You might not have to worry about one or two volunteers, but you should get rid of them from anywhere you grew tomatoes last season and anywhere you plan to grow them this season.
If you see them appearing on your compost pile, just turn it over and dig them in.
Learn more about growing tomatoes from seed in this guide.
Should You Compost Your Tomato Plants?
FAQ
What to do with old tomato plants?
Can you reuse compost from tomato plants?
Are rotten tomatoes good for compost?
Can you put tomato plants in a compost pile?
Tossing whole vines with unwanted fruits into your pile could cause batches of new tomato plants to pop up all over your garden come spring. Whilst we never say no to free tomato plants, unplanned tomatoes aren’t always welcome. Spreading your finished compost could lead to lots of “volunteer” tomato plants springing up in unexpected places.
Can Tomato plants be composted?
If you have tomato plants with some diseases like spotted wilt virus and curly top virus, they’re safe to compost ONLY if your pile gets hot enough to kill those diseases. An effective compost pile should have an internal temperature of around 135F, properly layered and kept moist.
Should you compost old tomato plants?
Once the gardening season has ended, there can be a great number of old tomato plants left lingering. Many gardeners feel that it’s essential to return the plants to the soil through composting. Others deem it far too risky when it comes to a possible spread of disease.
Why should you compost tomato plants?
Composting tomato plants improves the fertility and drainage of your soil. Composting tomato plants helps to suppress weeds and pests. Composting tomato plants helps to improve the growth and health of your plants. composting tomato plants is a great way to recycle organic material and improve the quality of your soil.