Companion planting is an advantageous garden design technique that utilizes the mutually beneficial qualities of compatible plants to create a healthy garden ecosystem. In this article, you’ll learn what to plant with tomatoes for healthier plants and tastier fruit, what to plant with tomatoes to keep bugs away, and which plants should not grow next to tomatoes.
Some plants attract pollinators and beneficial predatory insects like ladybugs, lacewings, and parasitic wasps that prey on garden pests. Other plants have intense aromas that repel insects and animals that feed on your beloved tomatoes.
While there is not a great deal of scientific research yet about the interactions between plants, many gardeners have been employing these strategies for generations.
In recent years, some horticulturists have started looking into companion planting from a scientific perspective.
Certain plants are even supposed to improve the flavor of tomatoes and help the plants grow larger and stronger. However, some plants do not get along and should live in separate areas of the garden.
- What Plants Grow Well with Tomatoes?
- What to Plant with Tomatoes to Attract Beneficial Insects
- What to Plant With Tomatoes to Keep Bugs Away
- Companion Planting Tomatoes with Trap Crops
- Companion Plants to Improve Soil Quality
- What Not to Plant with Tomatoes
What Plants Grow Well with Tomatoes?
While tomatoes are among the most popular garden veggies, there are a few pest and disease problems that even the most experienced gardeners struggle with at times.
You may find tomato leaves turning black or spot both big and tiny pests on the plant.
One way to combat the problem is with the proper space between tomato plants. Another is companion planting.
Companion planting, also known as interplanting, plant partnering, or polyculture, is an excellent tool for natural pest and disease control.
Some of the most familiar garden pests that tend to damage tomato plants include aphids, tomato hornworms, root-knot nematodes, spider mites, and whiteflies.
Unfortunately, aphids like tomato plants and a lot of other vegetation you may have in your garden. Various companion plants deter these insects through scent, and others attract their natural predators.
Another aspect of companion planting is pairing plants together that do not compete for the same growing space and nutrients. Companion plants are also useful for suppressing weeds, assisting pollination, improving soil quality, and reducing plant disease.
What to Plant with Tomatoes to Attract Beneficial Insects
Insects play a crucial role in a healthy garden ecosystem. Most flowering plants need pollinators to produce fruit. Even self-pollinating plants like tomatoes still benefit with a bit of help from bees and butterflies.
Certain types of plants attract beneficial predatory insects that feed on common garden pests like aphids, thrips, spider mites, and whiteflies and will keep bugs off tomato plants.
Some plants act as hosts for these insects to lay their eggs, while others have flowers that serve as a food source for omnivorous insects.
Native to South America, many gardeners grow varieties of Amaranthus for its edible seeds and leaves. It is also valued ornamentally for its vibrantly colored flowers and foliage.
Amaranth makes a good companion for tomatoes because it is a host plant for predatory beetles that eat garden pests. It also attracts birds and pollinators to the garden.
Bee balm, also known as Monarda and bergamot, is a perennial flowering plant that is excellent at attracting pollinators to the garden. When grown alongside tomato plants, bee balm reportedly improves the flavor and growth of tomatoes.
Borage, or Borago officinalis, is an excellent companion for many plants, including tomatoes. It is a pollinator favorite, drawing bees and butterflies to the garden.
Borage also attracts beneficial predatory insects like parasitic wasps and lacewings that lay their eggs on borage leaves. It reportedly improves the flavor of the fruit and helps its neighboring plants be more resilient against environmental stress.
Large borage leaves are useful as mulch around the vegetable garden. As they break down, they add valuable nitrogen and other nutrients to the soil. Borage is a large, fast-growing plant that freely self-seeds.
When companion planting tomatoes nearby, be sure to keep its space requirements in mind when choosing a growing location. Be diligent with removing spent flowers if you do not wish to see volunteer seedlings next season.
Tender young borage leaves and flowers are edible. They have a sweet, cucumber-like flavor.
Calendula (Pot Marigold)
Sometimes called pot marigold, Calendula officinalis is an incredibly useful choice for companion planting. The brightly colored flowers attract plenty of pollinators.
Pot marigold also serves as an essential host plant for numerous predatory insects like ladybugs, lacewings, and hoverflies that feed on aphids, thrips, whiteflies, hornworms, and other garden pests as both larvae and adults.
Dill, or Anethum graveolens, is a delicious garden herb that’s incredibly useful for attracting beneficial predatory insects to your vegetable garden. Some of these include lacewings, ladybugs, parasitic wasps, and tachinid flies.
These insects are mainly attracted to dill’s flowers. However, the herb does freely reseed itself if allowed. If you do not want to see volunteer dill seedlings next spring, remove the large flower heads before the seeds are mature. Dill seeds are also edible.
Avoid planting dill in very close proximity to your tomatoes, as the mature plants actually stunt the growth of tomatoes. It should grow nearby but not directly adjacent.
Oregano is an essential companion plant in the vegetable garden. Origanum vulgare attracts numerous types of beneficial insects, from pollinators like bees and butterflies to predators like lacewings. Its strong scent also repels cabbage moths.
However, to attract these insects, you must let oregano produce flowers, and the herb freely reseeds itself around the area.
To minimize its spread, remove the flower heads before the seeds are mature. Transplant or compost any volunteer seedlings you may find growing in unwanted places the following season.
Parsley is a staple culinary herb for many of our favorite tomato recipes. It also reputedly improves the flavor and growth of tomatoes when planted nearby.
Parsley, or Petroselinum crispum, attracts predatory insects like ladybugs and tachinid flies, which feed on pests like aphids and tomato hornworms.
Sweet alyssum is a beautiful and fragrant annual flower that is excellent for attracting pollinators and beneficial predatory insects like hoverflies and parasitic wasps to the garden.
When planted around the base of tomato plants, Lobularia maritima acts as a living mulch to suppress weeds, retain moisture, and keep the soil protected from wind and scorching sun in the summer.
What to Plant With Tomatoes to Keep Bugs Away
Have you ever wondered what to plant with tomatoes to keep bugs away? Many aromatic herbs and flowers act as natural insect repellents. Their strong odors overpower the scent of plants that garden pests like to feed on.
Plants repel certain pests through their natural compounds, fragrances, oils, and colors. Some plants, like garlic, have a strong enough odor to mask the scent of their companion plants. Various pests get confused by bright colors and avoid the area.
Members of the allium family, or Amaryllidaceae, include onions, garlic, chives, shallots, scallions, and leeks. They are effective at repelling many garden pests thanks to their strong scent.
In addition to deer and rodents, alliums repel aphids, armyworms, borers, caterpillars, slugs, spider mites, and whiteflies. Avoid planting members of the onion family near legumes like beans and peas. These plants reportedly stunt one another’s growth.
To control fungal diseases like early and late blight, leaf spot, and powdery mildew, treat tomato plants’ leaves with a garlic spray.
This spray also works as a contact insecticide, but be aware that it kills pests and beneficial insects like ladybugs, so be careful when applying. To make your own, follow this easy recipe.
Liquefy the garlic and water using a food processor or blender. Strain leftover garlic chunks, then pour the mixture into a clean spray bottle. Add one half-teaspoon of liquid dish soap and shake the bottle to blend the ingredients.
Thoroughly apply the spray to all parts of the plant, including both sides of the leaves. Insects sometimes hide, and fungal spores tend to emerge on the undersides of plants’ leaves.
This spray also works well as a pest repellent – it is mild enough to not damage plants’ leaves. Apply the garlic spray wherever you notice pest activity around your garden.
You may find that spritzing this mixture will also stop squirrels from digging in yard areas. Most rodents don’t like the odor.
Tomatoes and asparagus have a mutually beneficial relationship. Solanine is a chemical compound found in the nightshade family members like tomatoes, peppers, eggplants, and potatoes and works to repel asparagus beetles.
In turn, asparagus plants repel root-knot nematodes because their roots emit a natural nematocide. This compound kills nematodes that feed on the asparagus roots, which decreases the overall population as time passes.
Tomatoes and basil are soul mates, both on the plate and in the garden. Basil, or Ocimum basilicum, helps tomato plants grow stronger and produce the best tomato flavor.
This aromatic herb repels tomato hornworms, flies, mosquitoes, armyworms, asparagus beetles, thrips, and whiteflies. Its flowers also attract pollinators.
Marigolds are useful in the vegetable garden for their pest repellent properties. Their roots contain a chemical that kills nematodes that feed on them, which decreases their population over time.
French marigolds are said to be the most potent plants for pest control. The strong scent of marigolds also deters garden pests like tomato hornworms, thrips, cabbage worms, squash bugs, and whiteflies.
Their brightly colored flowers are a favorite for pollinators like bees and butterflies.
Companion Planting Tomatoes with Trap Crops
Some gardeners use a tactic called trap cropping. Plant a variety that the pests prefer a short distance away from the veggies you are trying to protect. The insects then feed on the trap crop instead of your precious tomatoes.
When the trap plant is full of insects, remove the entire plant and place it in a sealed plastic bag. Immediately dispose of the plastic bag in an outdoor garbage container with a lid.
Alternatively, leave the bag in the hot sun for several days to kill all insects and then compost the plant material.
Nasturtiums are very attractive to aphids and sometimes used as a trap crop to keep these pests off your tomatoes. Nasturtiums also act as host plants for numerous types of butterflies and predatory insects like hoverflies to lay their eggs.
When planting near tomatoes, give nasturtium plants plenty of space for their sprawling growth habit. Both the flowers and leaves of the nasturtium plant are edible and tasty. They have a bright, peppery flavor and make an excellent addition to summer salads.
Flea beetles are often problematic garden pests, especially early in the season shortly after transplanting. Plant radishes near your tomato plants to keep flea beetles from feeding on the tomato foliage.
These insects mostly prefer radish leaves, but be sure the radishes are growing closeby because the flea beetles do not move very far.
Companion Plants to Improve Soil Quality
Certain varieties make excellent companion plants because their growth habits are compatible. The most critical factors are root growth, branching patterns, and mature height.
As long as the plants are not competing for water, nutrients, or space, both above and below ground, growing certain plants near one another is more space-efficient and helps create a healthy, interactive garden ecosystem.
Low-growing plants act as living mulch to suppress weed growth and keep the soil moist and protected from wind and sun. In turn, taller plants provide partial shade and protection from the elements for cool-weather crops.
Members of the legume family, including beans and peas, are nitrogen fixers. These plants have a symbiotic relationship with soil bacteria that allows them to convert atmospheric nitrogen, which can’t be absorbed by most other plants, into ammonium nitrogen released into the soil through their root system.
This process makes them an excellent companion for most other veggies. Still, they should grow in an area away from members of the allium family, as these plants stunt each other’s growth.
When companion planting tomatoes with bush beans, keep each plant’s mature size in mind so that the tomatoes do not block the sunlight once they grow larger. If possible, plant tomatoes on the north side of your bush beans.
Plant leafy greens like lettuce, and spinach between tomato plants to act as a living mulch. Companion planting arugula with tomatoes also works well. These veggies prefer growing in cooler temperatures and filtered sunlight, so the tall tomato plants provide shelter from the intense summer sun.
Meanwhile, the low-growing leafy plants suppress weed growth and keep the soil from drying out as quickly. For a continuous harvest throughout the season, practice succession planting.
A few weeks before your first crop is spent, plant a second round of seeds. The seedlings emerge sheltered by the mature plants. Once the seedlings grow to be about three inches tall, remove the old plants to allow the second crop to grow.
What Not to Plant with Tomatoes
Some plants simply do not get along. While there is limited scientific research available regarding plant interactions, the topic is gaining more attention.
Over the years, generations of gardeners have observed various plant pairings that seem to inhibit one another’s growth and productivity. Many gardeners also recommend growing plants that tend to suffer from similar pest and disease problems separately.
That way, if one type of plant is attacked, its neighbors will be more resistant, and the problem does not spread as fast. Here are a few plants to keep away from your tomatoes.
Members of the cabbage family, including broccoli, Brussels sprouts, bok choy, collards, kale, kohlrabi, rutabaga, and turnips, should grow away from tomato plants. Brassicas stunt the growth of tomatoes.
Corn and tomatoes have a common enemy: the tomato fruitworm, also known as the corn earworm. It is best to refrain from growing plants that suffer from the same pest and disease problems close to one another.
Fennel, or Foeniculum vulgare, is excellent for attracting beneficial insects, both pollinators and predators. However, it, unfortunately, does not get along well with most other plants, including tomatoes.
It has been scientifically proven that fennel roots secrete a chemical compound that inhibits many other plants’ growth. Try growing the fennel in a pot or a separate section of the garden.
Other than tomatoes, members of the nightshade family, Solanaceae, include eggplant, peppers, and potatoes. Avoid growing these plants in the same area as tomatoes.
Doing so may increase the risk of developing quick-spreading disease problems like early and late blight and potato blight, affecting tomato plants.
These pathogens tend to accumulate in the soil, so crop rotation is beneficial. Avoid growing the same type of plants in each area of your vegetable garden for more than three seasons in a row.
Companion planting utilizes the mutually beneficial qualities of specific plants to create a naturally healthy and sustainable garden environment.
By planting herbs and flowers that attract beneficial pollinators and predatory insects and repel garden pests, you will be less reliant on using pesticides to keep your plants thriving.
When mimicking the way nature works, generations of gardeners have found a simpler, more natural, and more sustainable way of enjoying a bountiful harvest year after year.
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