Spider Mites On Tomato Plants | Identify, Kill, & Prevent
Have you recently found what appears to be cobwebs covering your entire tomato crop? These are likely spider mites on your tomato plants.
Continue reading to learn how to identify, kill, and more importantly, prevent them!

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I had my first real experience with spider mites in this summer’s garden and I hope to never deal with them again!
One day I had walked out to my garden truly just thinking there were a few cobwebs on my tomato plants. But in a few short days, the entire bed of tomatoes was infested!
In this post, my hope is to help you catch the problem before it’s too late!
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Signs of Spider Mites On Tomato Plants
Spider mites thrive in hot and dry conditions and so it’s very likely to find them towards the middle or end of summer.
In fact, they are named as one of the most destructive hot-season pests, especially for tomato plants.
The pest itself is nearly impossible to see and so you need to look out for the first signs they leave. Another reason why they are hard to spot is that they like to be out of the direct light and so they hide on the undersides of leaves.
In the beginning stages, you may notice tiny white and yellow spots on the leaves or you may even notice tiny holes.
As their population grows you’ll notice silky webs around the tomato stems and leaves.
Then once there is a heavy infestation you will notice dusty pale leaves completely covered in webbing.

See More in My Video Below
I recorded a YouTube video showing the damage they caused and I give a few tips for dealing with them. Be sure to click play and watch!
Spider Mite Damage
Spider mites feed on plant tissues which is why the leaves they are eating on eventually become discolored.
Just like with any major pest problem, if it goes untreated for too long it can be deadly to your plants. So the best thing is to start treating your plants as soon as possible.
Spider Mites Treatment
If you catch the mites early enough you can try spraying them off of the plant stems and leaves with the garden hose. After that, you should spray the plants down with neem oil which is a natural pesticide.
You should repeat treatment every 7 days or so until the spider mites are gone.
If the infestation is severe you should use a stronger treatment such as an insecticidal spray as well as something such as diatomaceous earth which is another all-natural solution.
One of the best ways to get rid of spider mites is to let beneficial insects such as ladybugs, lacewing larvae, and spined soldier bugs do the work for you!
It is one of the reasons why you should consider not killing the spider mites with an insecticide since doing so will also kill any beneficial insects you have.
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How to Prevent Spider Mites
One of the best methods I’ve researched for preventing spider mites is to thoroughly spray a liquid seaweed spray twice a week to the foliage of your tomato plants.
Seaweed extract is an organic fertilizer with more than 70 minerals, vitamins, and enzymes and can be used on all of your vegetables, flower beds, house plants, and lawn!
It is used to promote root growth, boost crop yields and plant growth, but most importantly it helps deter pests.
Be sure to grab your seaweed extract here!
Another simple way to prevent mites on future plants is to do daily checks.
Spider mites lay their eggs on the underside of leaves and so go through your plants and check the undersides of leaves and then spray off any eggs or pests you see. Then immediately treat with a mild solution if necessary.
Summary
All in all, spider mites are a huge problem, especially if they are not treated quickly!
They thrive in hot, dry, and dusty conditions. They leave white and yellow specks on the leaves. Turn the foliage to a dusty pale and bronze color. And they leave webbing on the stems and leaves of the plant.
Spider mites can be treated with neem oil, insecticide sprays, or diatomaceous earth. But if they get too out of control they’ll likely kill your plants.
Your best bet is to try to prevent them by spraying seaweed extract weekly. Planting beneficial plants to attract predator insects. As well as providing your plants with the best care to keep them healthy.
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Your article is helpful, thank you!
Wow! I wish I had known enough to have stopped spider mites from totally killing a beautiful cherry tomato plant that promised a healthy crop. I didn’t have these critters in Denver but learned of them in Long Beach, California. Thank you for the information and photos.
“check the undersides of leaves” for spider mite eggs?? You must have the best eyes on the planet, better than a hawk, if you can see spider mite eggs. Spider mites are easy to kill with Safers Soap, but it takes hours each day if you have large tomato plants, and the eggs aren’t affected. So you have to keep going back spending hours more every few days. And if you miss a few pregnant spider mites living in a crevice, they’ll come right back in a few weeks. I’m still looking for a real solution.
Thank you so much. very good information on tomato farming and their biggest problem, spider mites.