Anyone who makes their own compost will have an opinion about whether you can compost tomato plants or not. Some people have strong arguments against adding tomato plants to compost. Their reasons are certainly valid, but the question is, can you compost tomatoes or not?
The answer is a relatively simple one. If the tomato plants you are discarding are healthy, then it’s absolutely fine. If not, rather discard or burn them. The problem is that if your discarded tomato plants are diseased or infested with bugs, adding them to your compost heap will simply spread the pests and diseases.
What do you do with old tomato plants?
There comes a time when tomato plants stop producing fruit. They start to die and you can tell you need to pull them out of the ground.
But is it safe? It might be, but only if your dead tomato plants are healthy.
That might seem crazy, because why would you discard healthy tomato plants? The answer is simple.
They’ve reached the end of life and won’t carry on producing fruit. So, you might as well add them to the compost pile.
There’s another caveat. If there are flowers or fruit on your discarded tomato plants, they could self-seed. But it’s easy enough to destroy young seedlings and prevent them from growing.
If your old tomatoes aren’t healthy, take them to your local garden refuse outlet or burn them.
Note that we are talking about tomato plants here, and not the fruit that we eat. Sometimes there may be fruit or flowers on the plants, but generally, these aren’t viable.
Are tomatoes good in compost?
There’s a huge amount of research out there about how good compost is for tomatoes. But there’s not much about how valuable it is to compost tomato plants.
So, we did a bit of Internet digging and found a research paper written by Murat Durmus and Ridvan Kizilkaya published by the Ondokuz Mayis University in Turkey. They estimate that ten million tons of tomato waste are generated in Turkey every year.
It can’t be very different in other countries around the world. After all, tomatoes are a huge crop for farmers globally.
The Turkey-based researchers’ motivation was that there are lots of studies on the effect of compost on plant yield. But there are hardly any studies on the effects of tomato waste compost on tomato yield.
We know this to be true.
What they found was that tomato waste compost is a very good organic fertilizer. They also found that it increases both tomato yield and biological activities in soil.
But they did warn that it’s best to use tomatoes that have not been grown using chemical fertilizers.
This makes total sense. It also links directly to the theory that you shouldn’t throw diseased or pest-ridden tomatoes into the compost pile.
But then there’s the question we see so often. Should you compost your tomato fruit? Our question is why would you want to?
There is so much you can do with tomatoes other than chucking them on the compost pile. Rather pick them and make relish or tomato sauce.
If you can’t use tomato fruit because it is diseased, then trash it right now.
Benefits of composting tomato plants
The most obvious benefit of composting tomato plants is to get rid of those that have died. But, as Durmus and Kizilkaya say, “Tomato waste compost is a good organic fertilizer that increases both tomato yield and biological activities in soil.“
They maintain that after using the compost that was made with tomato plants, “tomato yield increased and biological properties of soil improved.”
Other than that, it’s difficult to know whether tomato plants will yield any more benefits to compost than other vegetable matter. After all, all veggie leaves and leftovers make a great addition to compost.
When you compost tomatoes, tomato vines, or any other part of tomatoes, be sure to dig the bits into the compost pile. It’s very important to make sure that all the ingredients make contact with each other so that they break down as quickly as possible.
It’s a bit like a cake. You need to mix everything together to ensure it all creates its magic.
Risks of composting tomato plants
Tomatoes get diseases easily, so you do need to be careful when you add them to compost. The problem is that our backyard compost piles don’t ever reach the high temperatures needed to kill spores and pathogens.
This means that they won’t ever get hot enough to kill the diseases or mold and fungal spores that can affect all your other plants. It may not happen immediately, but these problems can cause serious damage to future crops.
If you are sure that your tomato plants are healthy. Then there won’t be any sort of risk.
For example, if you have a tomato plant with the spotted wilt or curly top virus, you’re relatively safe. Neither of these diseases survives very long after the plant dies. They also aren’t spread to plants from the soil.
But if your plants have any fungal or bacterial diseases, don’t even begin to think about composting tomato plants. Also, remember that plants can have more than one disease at a time.
The main problem is that bacterial and fungal diseases can survive in the compost to create problems again next year. This is one of the reasons farmers rotate the same and related crops so that they don’t grow in the same soil year after year.
Ultimately, if your tomato plants are not diseased you can compost them. There are a few viruses that won’t survive the composting process, but you need to be able to identify these.
Tomatoes do break down quickly and if you add organic material they will add value to your compost heap. So, give it a try. But don’t be tempted to chuck in any plants that might have been attacked by pests or diseases.