Aphids may be tiny, but they can pose big problems for your tomato plants. These sap-sucking pests can affect the growth, health, and yield of your tomatoes, so what can you do about aphids on tomato plants?
The good news is that there are several choices at your disposal. There are proven ways to eliminate aphids on tomato plants naturally, and products you can use to combat pest populations.
If you are struggling with these pesky tomato pests, we are here to help. I have grown tomatoes for years, including as a professional kitchen gardener, and also sought some specialists to reveal five expert-recommended ways to deal with aphids on tomato plants.
5 ways to get rid of aphids on tomato plants
The following recommendations will either rid your tomatoes of aphid problems or decrease the chances of your plants falling foul of the sap-sucking pests.
1. Spray with water or organic mixes
In reality, this is a few potential solutions for aphids on tomato plants all wrapped up under one overarching 'spray' header. As there are several different things you can 'spray' and which you choose may depend on your gardening preferences or ethos.
Let's start with the simplest solution, as recommended by Susan Mulvihill, an experienced grower and author of The Vegetable Garden Pest Handbook. She advises: 'I just spray aphids with water from our garden hose to knock them off the plants, which is a simple, eco-friendly solution.'
Another organic solution for spraying tomato plants to combat aphids, as suggested by Emily Jones, is insecticidal soap. She says: 'A good organic spray solution is homemade insecticidal soap - a mix of mild liquid soap and water to spray the infected plants, targeting soft-bodied insects like aphids and whiteflies.'
'An alternative to insecticidal soap is neem oil – all you need to do is apply neem oil spray to control the wide range of pests,' adds Emily.
2. Use natural predators
Aphids on tomato plants can be combated by attracting, or introducing, beneficial insects that are natural predators of the sap-sucking pests. For example, ladybugs, lacewings, and hoverflies are predators of aphids and can potentially eat 50 a day, and hundreds in their lifetime.
You can attract ladybugs to a yard, as well as other beneficial insects, by planting pollen-rich plants to tempt in the insects. Umbellifer plants are particularly great at attracting ladybugs and hoverflies. In addition, providing habitats or making a bug hotel will attract beneficials and give them a sheltered spot to settle.
An alternative to luring them in is to buy ladybugs to release into the garden or greenhouse to combat aphid problems. You can also get live lacewings, such as these green lacewing eggs available at Amazon.
It is best to release purchased ladybugs at cooler times of day, such as early morning or in the evening. Emily Jones claims: 'Generally, you need at least 1500 of these bugs to deal with a handful of aphid-infested tomato plants. You can arrange for two or three releases (weeks apart) to achieve maximum effectiveness.'
3. Use diatomaceous earth
Many readers may wonder, 'What is diatomaceous earth (DE)?' It is a natural, powdery substance made of tiny ground-up fossilized remains and is a useful means of non-toxic pest control. As well as aphids, DE can combat slugs, snails, mites, thrips, and more.
If a tomato plant is infested with aphids, sprinkle the DE on both sides of the leaves, concentrating the application on particularly overrun areas. The aphids will get cut by the jagged substance as they crawl over it, causing them to dehydrate and die.
A couple of pointers about using DE. Firstly, though it is safe for humans and pets, it is always recommended to wear protective glasses and a dust mask (Such as this safety kit available at Walmart). Also, be wary of applying it if the plants are flowering, especially around the blooms themselves, as it also risks killing pollinators.
4. Try companion planting
Companion planting is a great form of natural pest control, and certain plants keep aphids at bay, stopping them from coming near your tomatoes. These tomato companion plants all emit strong aromas disliked by aphids, which keep the pests away and mask the presence of the tomato plants.
Alliums such as garlic, onions, and chives will deter aphids with their pungent odour, while strong-smelling aromatic herbs like lavender, rosemary, mint, and dill can confuse pests and keep them away from tomatoes.
During my years as a professional kitchen gardener, I always grew marigolds with tomatoes. This is because the flowers emit a scent that repels many tomato pests, including aphids.
I always recommend planting marigolds in a vegetable garden as they offer many benefits in terms of repelling pests and attracting beneficial insects. These 'Sparky Mixture' Marigold seeds at True Leaf Market are the more pungent French types of marigolds and have unique semi-doubled heads.
5. Trap the aphids
Finally, there are methods you can use to trap aphids and get them away from your tomato plants. This can be achieved in one of two ways.
The first is to use sticky traps. These commonly come in the shape of yellow cards covered on both sides with sticky material (such as these yellow sticky traps available on Amazon). They can hang around tomato plants to catch aphids, as the pests are attracted to the color yellow, get stuck in the trap, and die.
These are not ideal solutions, though, as they will get flying aphids but not those already on a plant and enjoying the meal at hand. Plus, beneficial insects that are in the vicinity and helping you out also risk getting stuck in the trap.
An alternative is to use a trap plant for pest control. This trap plant can be purposefully planted to attract the aphids and keep them distracted away from your tomato plants.
The ideal trap plant for aphids is nasturtium. When you grow nasturtiums, aphids are always really attracted to them.
This makes nasturtiums effective for pest control; they can keep aphids away from more precious plants, and having all the aphids congregated on one plant can make an infestation easier to manage.
