When to Plant Dill & Best Companion Plants

Companion plants for dill

What to grow next to dill, what to keep away, and what is only tradition. Every pairing says how strong the evidence is.

Grow together 8

Helps, or shares the bed well.

Broccoli Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Broccoli guide
Cauliflower Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Cauliflower guide
Cabbage Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Cabbage guide
Kale Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Kale guide
Brussels sprouts Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Brussels sprouts guide
Bok choy Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Bok choy guide
Kohlrabi Studied Dill flowers feed the parasitic wasps that attack cabbage worms and aphids. Insectary plants like this have research support.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023; Brassica flea beetles, UMass Amherst Vegetable Program. Kohlrabi guide
Cucumber Practical Flowering dill feeds parasitic wasps and hoverflies that prey on aphids and caterpillars.

Source: Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023. Cucumber guide

Keep apart 1

Shared pests, disease or competition.

Carrot Practical Same family: dill shares carrot rust fly and, if both flower, can cross with carrots grown for seed.

Carrot guide

Tradition only 2

On many charts, with little or no evidence.

Tomato Tradition Said to harm Mature dill is said to stunt tomatoes. There is no research behind it, and young dill flowers attract beneficial insects.

Tomato guide
Cherry tomato Tradition Said to harm Mature dill is said to stunt tomatoes. There is no research behind it, and young dill flowers attract beneficial insects.

Cherry tomato guide

Studied Field or lab research shows an effect, at least under some conditions.

Mixed Some studies find an effect, others don’t, or it only works in a narrow way.

Practical Explained by light, space, timing, support or a shared pest or disease.

Tradition Widely repeated, but with little or no evidence behind it.

See every pairing side by side in the companion planting chart, or try them in a bed with the garden planner.

When to plant dill by city

Sow dill outdoors up to 3 weeks after your last frost. Here is what that means for 2027 in cities across the US, using each city’s average frost dates (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.

City	Last frost	Sow outdoors
Seattle, WA (9a)	Mar 13	Mar 13 – Apr 3
Portland, OR (8b)	Feb 25	Feb 25 – Mar 18
Sacramento, CA (9b)	Jan 12	Jan 12 – Feb 2
Phoenix, AZ (10a)	Jan 5	Jan 5–26
Salt Lake City, UT (7b)	Mar 31	Mar 31 – Apr 21
Denver, CO (6a)	Apr 30	Apr 30 – May 21
Dallas, TX (8b)	Mar 2	Mar 2–23
Minneapolis, MN (5a)	Apr 23	Apr 23 – May 14
Kansas City, MO (6b)	Apr 4	Apr 4–25
Chicago, IL (6b)	Apr 10	Apr 10 – May 1
Columbus, OH (6b)	Apr 20	Apr 20 – May 11
Nashville, TN (7b)	Apr 1	Apr 1–22
Atlanta, GA (8a)	Mar 24	Mar 24 – Apr 14
Raleigh, NC (8a)	Mar 28	Mar 28 – Apr 18
Philadelphia, PA (7b)	Mar 30	Mar 30 – Apr 20
Boston, MA (7a)	Apr 4	Apr 4–25

In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: grow dill from fall through winter.

Dill spacing

In a square-foot bed, plant 1 per square foot. In traditional rows, space plants about 12 inches apart with 18 inches between rows.

Its flowers feed parasitic wasps and hoverflies. Self-sows freely.

One square foot planted with dill, as drawn in the planner.

How to grow dill

Dill is an easy annual herb that grows fast from seed and is useful for both its feathery leaves and its seed heads for pickling. Its flat flower clusters attract parasitic wasps, hoverflies and other beneficial insects, and it self-sows freely.

Sun and soil

Full sun and well-drained, moderately fertile soil with a pH of about 5.5–6.5. Tall types can reach 3–4 feet, so a spot sheltered from wind helps.

Planting

Sow directly; dill has a taproot and transplants poorly.
Sow ¼ inch deep from the last frost date up to 3 weeks after, when soil is about 60°F.
Thin to 12 inches apart in rows 18 inches apart.
For a steady supply of leaves, sow again every 3–4 weeks.

Care

Water moderately; avoid soggy soil.
Stake tall varieties or let them lean on a fence.
Cut seed heads before they shatter if you do not want dill coming up all over the garden next year.
Leave black swallowtail caterpillars if you can spare the foliage; they become butterflies.

Harvest

Snip leaves once plants are about 6 inches tall; flavor is strongest just as flowers begin to open. For seed, cut heads when the seeds turn tan to brown, then hang them upside down in a paper bag to finish drying.

Common problems

Aphids: Common on flower heads and stems. Rinse off with water; predators usually follow.
Early bolting: Heat and crowding cause plants to flower before making many leaves. Thin properly and use slow-bolting varieties.
Plants falling over: Tall stems flop in wind and rain. Stake them or grow a dwarf variety.

Varieties to try

'Fernleaf' — compact (about 18 inches), slow to bolt
'Bouquet' — early, large seed heads
'Dukat' — leafy, strong flavor, slow to bolt

Crop rotation

Dill belong to the carrot family (Apiaceae). Carrot rust fly and leaf blights carry over. Light feeders. Relatives that count as the same family for rotation: carrot, parsnip, celery, parsley, cilantro.

Frequently asked questions

When should I plant dill?

Sow dill outdoors up to 3 weeks after your last frost. Type your ZIP code above for exact dates, or see the city table.

What grows well with dill?

Good neighbors for dill include broccoli, cauliflower, cabbage, kale, brussels sprouts and bok choy. Each one is listed above with the reason and how strong the evidence is.

What should not be planted with dill?

Keep dill apart from carrot. Same family: dill shares carrot rust fly and, if both flower, can cross with carrots grown for seed.

How far apart should I plant dill?

In rows, space dill about 12 inches apart with rows 18 inches apart. In a square-foot bed, plant 1 per square foot.

How long do dill take to grow?

About 40–60 days from sowing to first harvest, depending on the variety and the weather.

Can dill handle frost?

Dill tolerate a light frost but not a hard freeze. Cover them if temperatures will drop into the mid-20s °F.

Sources

Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
Brassica flea beetles, UMass Amherst Vegetable Program
Dill in the Garden — Utah State University Extension

More free garden tools

Plan your beds

Garden planner
Draw your beds square by square and check every neighbor.
Square foot gardening chart
How many of each plant fit in one square foot.
Raised bed soil calculator
Cubic feet, cubic yards and bags for any bed.
Three Sisters garden
Corn, beans and squash: layout, timing and what the research says.

When to plant

Planting calendar
Sowing and planting dates for your ZIP code.
Frost dates by ZIP code
Last spring and first fall frost, with the odds.
Growing zone by ZIP code
Your USDA hardiness zone and what it does and doesn’t tell you.
Seed starting calculator
When to start each seed indoors.

What grows together

Companion planting chart
Good and bad neighbors, graded by evidence.
Plant guides
When to plant and what to plant with 55 vegetables, herbs and flowers.