Companion planting is an age-old method that farmers and gardeners have been using for hundreds of years.
Marigolds are often on lists of great tomato companion plants, but it’s often a struggle to find out why they are such great companions.
Why You Should Plant Marigolds and Tomatoes Together
There are a number of reasons to plant marigolds and tomatoes together. But here are the top ones that will positively impact your garden.
1. Marigold Flowers Attract Pollinators Like Bees
Marigolds produce beautiful flowers that are larger enough to attract a lot of pollinators and beneficial insects to the garden. This is a big benefit and can help make sure your tomato flowers are effectively pollinated.
The bees will visit other plants in the garden as well, so you’re not only going to be helping your tomatoes thrive but other flowers as well.
2. Get Rid of Tomato Hornworms
If you’ve grown tomatoes before, you know about the dreaded tomato hornworm. They blend in quite nicely with the stems and leaves of the plants, but they can destroy a plant in just a matter of days.
Marigolds are great on two fronts when it comes to tomato hornworms:
- The strong odor of the marigold flowers helps keep the moths from coming near your tomatoes to lay their eggs.
- Marigolds also attract pollinators like parasitic wasps, which will lay their eggs on hornworms.
If you’ve ever seen a hornworm with white rice-looking things all over it, leave it alone. That worm is a dead man walking — because as soon as those parasitic wasp eggs hatch, they are going to feed on the hornworm.
3. Reduce Whitefly Infestations on Your Tomato Plant
Planting French marigolds near the tomato plant is said to reduce the impact of the glasshouse whitefly, and the research backs it up!
The theory was that limonene levels, which is a chemical that marigolds give off, is said to help control whiteflies on tomato plants. By planting marigolds around your tomato plants you can reduce the impact of the younger whitefly populations.
A study published in 2019 showed that and the “French marigold was found to be an effective companion plant” for tomatoes.
However, you can’t just add marigolds to the area after a whitefly infestation has already begun as it won’t have the same impact.
“Significant control of whitefly was achieved when marigolds were intercropped amongst tomatoes from the beginning of the growth period. However, introducing marigolds as a replacement for chemical control methods after significant whitefly infestation produced minimal effects.”Conboy NJA, McDaniel T, Ormerod A, George D, Gatehouse AMR, Wharton E, et al.
4. Planting Marigolds Attract Slugs and Snails Away From Your Tomatoes
Slugs and snails are another one of the tomato pests that can do quite a bit of damage to your tomato crop.
By planting marigolds nearby, you are sending those suckers towards the flowers instead of your tomatoes. Many gardeners will plant a border of marigolds around tomato plants to act as a “trap crop” and keep the snails or slugs from going any further.
5. Marigolds Can Help Deter Larger Pests Like Deer, and Squirrels
Marigold flowers have a strong scent, and that scent can be a great deterrent for deer, squirrels, and other animals that eat tomatoes.
While they aren’t going to completely save your plants, their scent can help these animals from looking elsewhere for food.
6. Control and Destroy Root-Knot Nematodes
Root-knot nematodes are a big issue when it comes to the health of tomato plants. So much so that some tomato varieties are even bred to resist nematodes and keep the soil healthy.
But you don’t have to plant those, you can just plant marigolds nearby!
The University of Florida Extension says that the roots of the marigolds contain a “substance called alpha-terthienyl, which can aid in the reduction of root-knot nematodes.”
If there is an area of the garden you know has suffered from these in the past, you can plant marigolds there to help bring back the health of the soil.
African and French marigolds are best for this application and you’ll want to plant them at least 2 months before other crops to have the desired effect.
Marigolds Attract Aphids So Your Tomatoes Don’t Suffer
While marigolds are often on lists of plants that deter aphids, that’s not exactly true. Yellow is a color that attracts aphids, so marigold plants do deter them from eating your tomatoes since they’ll be more attracted to the marigold flowers.
By planting marigolds, aphids (and spider mites!) will stay away from tomatoes and instead feed on the marigolds. You’re essentially planting a sacrificial plant to help save your tomatoes from aphids.
Frequently Asked Questions About Marigolds and Tomatoes
What is the Best Marigold to Plant With Tomatoes?
The French Marigold and African Marigolds are the ones found to have the most beneficial impacts on tomato plants.
Do not plant hybrid varieties as they don’t have the same effect on controlling pests.
These include cultivars like:
- Disco Series
- Durango Series
- Dwarf Bonanza Blend
- French Brocade
- Gold Coin
- Golden Gate Series
- Golden Guardian
- Ground Control
- Gypsy Sunshine
- Hero Series
- Janie Series
- Jolly Jester
- Lemon Drop
- Mr. Majestic
- Naughty Marietta
- Petite Series
- Queen Sophia
- Red Marietta
- Safari Series
- Scarlet Sophie
- Spanish Brocade
- Sparky Mix
- Striped Marvel
- Spice Series
- Yellow Boy
Do Marigolds Keep Tomato Worms Away?
Marigolds are said to keep tomato worms, including the dreaded hornworm, from ravaging your plants. They also help keep whiteflies and aphids away from your plants.
What Plants Benefit From Marigolds?
Marigolds don’t only benefit tomato plants, they are also great companions to a wide variety of other garden vegetables like:
You can also check out the full list of great Marigold companion plants here.
How Close to Plant Marigolds to Tomato Plants?
To work effectively and have the results mentioned above, you’ll want to make sure you’re properly spacing your tomatoes and marigolds together.
Marigolds should have around 7 inches of growing space on every side, but not much more than that. You can grow marigolds in a border around your vegetable garden rows or raised tomato beds.
What is Companion Planting?
Companion planting is basically planting certain plants together to improve the growth of one or both.
Companion planting can help deter pests while attracting beneficial insects and pollinators into the mix. Tomatoes need a lot of pollinators to get those flower buds turning into fruit!
What Are the Benefits of Companion Planting?
Companion planting is about putting together plants that will either help or not hurt each other. Some are believed to ward off pests, vermin, and diseases. It is said that if you plant certain plants together, then the whole becomes greater than the sum of its parts. You can attract helpful predator bugs when you grow marigolds or sunflowers. You can keep aphids away by planting mint. And on, and on.
Attracting Beneficial Insects
The best thing about companion planting is attracting beneficial insects. You want to attract these guys because they’re eating up your bad bugs. Besides, they are also pollinators. If you have an herb garden or vegetable garden, then surely you know how important bees and butterflies are.
The most obvious example of this is growing tomatoes and basil together. The combination of the two just makes your tomatoes taste INCREDIBLE.
Organic Pest Control
Growing your tomatoes near specific herbs and plants will give the tomato a boost of natural pest repellant.
Companion planting is a great way to help increase the health of your tomato plants and get a bigger yield.
Some of the pests that marigolds can help keep away from tomatoes are:
These are just a few, but they are some that can definitely impact the growth of your tomatoes.
Planting Marigolds & Tomatoes Together
Planting marigolds and tomatoes as companion plants is a great way to improve your harvest and ensure a more healthier tomato plant.
Now that you have some of the major tomato pests under control, make sure you’re choosing the right tomato fertilizer to reduce the chances of blossom end rot and nutrient deficiencies.