Record — updated 2026-07

Dill Companion Plants

Entry No. 046

Anethum graveolens · carrot family family · rotation group: other

The best companion plants for dill are Cabbage, Broccoli, Cucumber, Lettuce, and Onion. Avoid planting dill near Carrot, Tomato. Of the 9 pairings recorded here, 2 are supported by published research and 6 are traditional practice with no controlled evidence behind them.

Research-backed tested in controlled research Traditional long practice, untested Not supported tested and not supported

What to plant with dill

Companion plants for dill — 2 research-backed, 4 traditional
Plant	Claimed benefit	Evidence	What the evidence actually shows
Broccoli	Flowering dill recruits parasitic wasps and hoverflies that suppress aphids and loopers.	Research-backed	Clemson Extension explicitly recommends dill as a small-flowered insectary plant; the nectar benefit to parasitoids is measured, the yield benefit is not. Source: Ballew, J. (2022), Attracting Beneficial Insects to Your Vegetable Garden, Clemson HGIC
Cabbage	Dill flowers are among the best nectar sources for the parasitoid wasps that attack brassica pests.	Research-backed	Dill was the single best floral nectar source tested, raising parasitoid median survival by 17.5 days over water and sharply increasing wasp glycogen reserves; the crop-level payoff still needs field confirmation. Source: McIntosh et al. (2020), Floral Resources for Trissolcus japonicus, a Parasitoid of Halyomorpha halys, Insects 11(7):413
Cucumber	Dill is the classic pickling partner and is said to draw pollinators to cucumber flowers.	Traditional	The culinary pairing is real; the horticultural benefit is untested, though any umbel flower does attract pollinators. Source: Growing dill in home gardens, University of Minnesota Extension
Lettuce	Dill draws hoverflies whose larvae eat lettuce aphids.	Traditional	Mechanism is sound and shared with alyssum, but alyssum is the plant actually trialled in lettuce, not dill. Source: Dill, Anethum graveolens, Wisconsin Horticulture, UW-Madison Extension
Onion	Onions are said to grow well alongside dill without competing.	Traditional	A spacing and timing convenience; no biological interaction demonstrated. Source: Growing dill in home gardens, University of Minnesota Extension
Sweet Corn	Dill is said to attract beneficials that reduce corn earworm pressure.	Traditional	Repeated widely in companion charts; no controlled evidence located. Source: Dill, Illinois Extension Herbs

What not to plant with dill

Plants to keep away from dill
Plant	Claimed problem	Evidence	What the evidence actually shows
Carrot	Dill and carrot are close relatives that share pests and may cross.	Traditional	Same-family rotation logic is sound; the frequently cited claim that dill stunts carrots has no trial support. Source: Anethum graveolens, NC State Extension Gardener Plant Toolbox
Tomato	Mature dill is said to stunt tomatoes.	Traditional	No controlled evidence; the real consideration is that dill hosts black swallowtail larvae and competes for light once it reaches 3-4 feet. Source: Dill, Anethum graveolens, Wisconsin Horticulture, UW-Madison Extension
Fennel	Dill and fennel should not be planted together because they cross-pollinate.	Not supported	Extension guidance does say keep them apart, but the cross-pollination rationale is wrong: Anethum and Foeniculum are different genera and do not interbreed. Source: Growing Herbs at Home, G6470, University of Missouri Extension

The honest verdict

Of everything gardeners recommend planting alongside dill, 2 pairings have been tested properly: Cabbage, Broccoli. Those are the ones worth planning your bed around.

The remaining 4 pairings on this page are traditional practice. They circulate on every companion planting chart online, but we could not find controlled evidence testing them. They are not wrong so much as unverified — most cost nothing to try, and interplanting flowers and herbs has its own well-documented benefit of pulling pollinators and predatory insects into the garden.

Widely repeated, not supported: Fennel — Extension guidance does say keep them apart, but the cross-pollination rationale is wrong: Anethum and Foeniculum are different genera and do not interbreed.

Every row above links to the publication it came from. See how we grade evidence.

Growing dill: the numbers

Field data — Dill
Sun	Full sun (6+ hours)
Water	Moderate
Spacing	12 in apart · 24 in between rows · 1 per square foot
Mature size	about 36 in tall
Soil pH	5.8–6.5
Days to maturity	40–55 days
Frost tolerance	Half-hardy — takes a light frost
Containers	Yes — 3 gallon minimum
Common pests	aphids, black swallowtail larvae
Common diseases	powdery mildew, leaf blight

When to plant dill

Zone 6b shown

Start indoors Sow / transplant outdoors Harvest

Direct sow outdoors: Apr 3 – Apr 16 — 1 week before last frost

Expected harvest: May 13 – May 28 — 40–55 days from planting

Fall planting: Aug 18 – Aug 31 — 10 weeks before your first fall frost

Those dates are for zone 6b. Get your own dates by ZIP code →

Varieties worth knowing

seeds

Bouquet — most widely grown; large seed umbels for pickling
Fernleaf — dwarf and slowest to bolt; best container type
Dukat — heavy leaf yield with strong flavour
Long Island Mammoth — tall classic pickling type

Variety names link to seeds on Amazon. As an Amazon Associate we earn from qualifying purchases. These are the varieties named in the extension sources for this crop, not a paid placement — where a source recommended a variety for a specific reason, that reason is the note beside it.

Put it in a bed

The garden planner checks every square against this ledger as you place crops — if you drop dill next to something recorded as a bad neighbour, the square turns red and tells you why.

Records for the plants named above:

Cabbage Broccoli Cucumber Lettuce Onion Sweet Corn

Same rotation group (other) — don't follow one with another:

Asparagus Celery Okra Rhubarb Sweet corn Sweet Potato

Dill companion planting questions

What should not be planted next to dill?

Carrot, Tomato. Dill and carrot are close relatives that share pests and may cross. Same-family rotation logic is sound; the frequently cited claim that dill stunts carrots has no trial support.

How far apart should dill be planted?

Space dill about 12 inches apart in the row, with 24 inches between rows. In a square-foot bed that works out to 1 plant per square foot.

Does companion planting with dill actually work?

Partly. 2 of the pairings on this page are backed by published research — Cabbage, Broccoli. The rest are traditional practice: plausible, harmless to try, but untested. Treat the folklore as a starting point rather than a rule, and read what the evidence says about companion planting.

When should I plant dill?

Direct sow outdoors 1 week before last frost. In zone 6b that means roughly Apr 3 – Apr 16. Get exact dates for your ZIP code →

Sources for this record

Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.