Yes, you can plant dill near tomatoes, but with one important catch
Dill and tomatoes can grow in the same garden bed, and dill actually helps tomatoes by attracting beneficial insects that eat common tomato pests. However, dill and tomatoes compete for the same nutrients and water, so they need space between them—at least 12 to 18 inches apart—to avoid stunting each other. If you plant them too close, both plants will struggle.
The real issue is that dill grows tall and can shade tomato plants if you're not careful about placement. Dill reaches 2 to 3 feet tall depending on the variety, so plant it on the north side of your tomatoes (in the Northern Hemisphere) so the afternoon sun still reaches your tomato leaves. This positioning also makes harvesting easier for both plants.
Key Takeaways
- Dill attracts parasitic wasps and hoverflies that prey on aphids, spider mites, and other tomato pests, making it a useful companion plant.
- Space dill at least 12 to 18 inches away from tomato plants to prevent competition for water and nutrients.
- Plant dill on the north side of tomatoes to avoid shading the tomato foliage during the growing season.
- Dill bolts (flowers and goes to seed) quickly in hot weather, so succession plant every two to three weeks if you want continuous harvests.
- Both plants prefer similar soil conditions—well-draining soil with moderate fertility—so they work well in the same garden area.
How dill helps tomato plants
Dill flowers attract parasitic wasps and hoverflies, two insects that lay eggs in or feed on common tomato pests. Parasitic wasps lay eggs inside aphids, which kills the aphid. Hoverflies eat spider mites, whiteflies, and small caterpillars. Neither insect harms tomatoes or humans—they're just doing what they evolved to do.
This is why dill is called a companion plant. You're not relying on chemicals; you're creating an environment where natural predators move in. The dill flowers bloom over several weeks, so the beneficial insects stay in your garden longer than they would if you had no flowering plants nearby.
Dill also has a reputation for improving soil structure as it breaks down, though the effect is modest. The real benefit is the pest control, especially if you've had problems with aphids or spider mites on tomatoes in past seasons.
Spacing and placement to avoid competition
The 12 to 18 inch spacing rule comes from the fact that both dill and tomatoes have shallow root systems that spread outward rather than deep. If they're closer than this, their roots overlap and they compete for water and nutrients. Tomatoes are heavier feeders than dill, so a crowded dill plant will suffer first—it will be stunted and produce fewer leaves to harvest.
Place dill on the north side of your tomato plants (assuming you're in the Northern Hemisphere). Dill can tolerate partial shade, but tomatoes need 6 to 8 hours of direct sun daily. By putting dill to the north, you keep the afternoon sun on your tomato foliage while dill gets morning light and afternoon shade, which actually helps it stay tender longer before bolting.
If you're growing tomatoes in containers, you can plant dill in a separate pot nearby. This gives you complete control over spacing and makes it easier to move the dill if it starts shading the tomato pot as it grows.
Soil and water needs are compatible
Both dill and tomatoes prefer well-draining soil with a pH between 6.0 and 7.0. Neither plant likes soggy soil, so if you've prepared your tomato bed with compost and sand to improve drainage, dill will thrive in the same conditions. You don't need to amend the soil differently for dill.
Water both plants when the top inch of soil feels dry. Dill is slightly more drought-tolerant than tomatoes, so it won't suffer if you miss a watering, but consistent moisture produces better leaf flavor. In hot climates, mulching around both plants helps retain moisture and keeps roots cooler.
Dill doesn't need heavy fertilizing. If your tomato bed is already amended with compost or balanced fertilizer, dill will get what it needs. Over-fertilizing dill produces lots of leafy growth but weaker flavor.
Managing dill's fast bolting cycle
Bolting is when dill stops producing leaves and starts flowering and setting seed. This happens quickly—often within 4 to 6 weeks of planting—especially in hot weather above 75°F. Once dill bolts, the leaves become bitter and tough, and you'll want to pull the plant out to make room for something else.
To have fresh dill throughout the tomato season, plant a new row of dill seeds every two to three weeks from spring through early summer. This is called succession planting. Plant the first batch when you plant tomatoes, the second batch three weeks later, and so on. By the time the first planting bolts, the second is ready to harvest.
If you want dill to flower for the beneficial insects, let one or two plants bolt intentionally. The flowers are edible and attractive, and they'll draw in the parasitic wasps and hoverflies you want. Just keep harvesting the younger plants for kitchen use.
Varieties that work well with tomatoes
Bouquet dill is a compact variety that reaches only 18 inches tall, making it less likely to shade tomatoes. Fernleaf is another dwarf type, growing to about 12 inches, and it bolts more slowly than standard varieties, giving you a longer harvest window. Both are good choices if you have limited space.
Mammoth or Long Island dill grows 3 feet tall and produces abundant foliage, but you'll need to plant it farther away from tomatoes or on the north side to avoid shading. These varieties are better if you want to harvest large quantities of dill for pickling or drying.
All dill varieties attract the same beneficial insects, so choose based on your space and how much dill you want to harvest. Dwarf varieties are easier to manage in a small garden bed with tomatoes.
When dill and tomatoes don't work together
Dill can become a problem if you let it self-seed. Dill seeds germinate readily and will pop up all over your garden bed the following season, competing with tomatoes and other plants. If you don't want dill coming back year after year, pull plants before they drop seeds, or deadhead the flowers as soon as they appear.
In very hot climates (above 85°F regularly), dill bolts so fast that you may not get much leaf harvest before it flowers. In this case, you might skip dill as a companion plant and focus on other beneficial plants like basil or borage, which handle heat better while still attracting helpful insects.
Dill also doesn't pair well with fennel—they're in the same plant family and can cross-pollinate, producing hybrid seeds that don't grow true. If you're growing fennel elsewhere in your garden, keep it far from dill.
Frequently Asked Questions
Will dill attract bad insects to my tomatoes?
No. Dill attracts beneficial insects that eat tomato pests, not pests themselves. Dill flowers may attract some aphids, but the parasitic wasps and hoverflies that come for the flowers will eat those aphids. The trade-off is always in your favor.
Can I plant dill and tomatoes in the same pot?
Not successfully. A single large pot (5 gallons or bigger) might work temporarily, but both plants will compete for nutrients and water. Two separate pots placed close together gives you the companion plant benefit without the competition.
What's the best time to plant dill with tomatoes?
Plant dill at the same time you plant tomato seedlings or transplants. Dill grows quickly from seed, so it will be ready to flower and attract beneficial insects by the time tomatoes are established and facing pest pressure.
Can I use dill clippings while the plant is still growing?
Yes. Pinch off the top leaves and stems regularly to encourage bushier growth and delay bolting. Just leave enough foliage on the plant to keep it healthy. Harvesting actually extends the productive life of dill.
Do I need to stake or support dill near tomatoes?
Tall varieties like Mammoth may need light staking in windy areas, but most dill stands on its own. If you're using a tomato cage or stake for your tomatoes, position dill far enough away that it won't tangle with the support structure.