Dill

Dill (Anethum graveolens) is a plant you get two usable crops from - the feathery leaves (dill weed) and the seed heads (dill heads or dill seed). Fronds are ready in 40-60 days; full seed head maturity takes 90-110 days. You can harvest fronds continuously while waiting for the heads, or dedicate some plants to head production. A packet of dill seeds costs under two dollars and will last you multiple seasons.

What you’re actually growing

Anethum graveolens is a single species in the carrot family (Apiaceae) with relatively few cultivar types that matter for home growing. Standard tall varieties like ‘Mammoth’ and ‘Long Island Mammoth’ reach 3-4 feet and are the classic choice for dill heads and pickling - the large umbels produce more seed. Dwarf types like ‘Fernleaf’ stay under 18 inches and are bred for leaf production with delayed bolting, making them more practical for container growing or small beds where you want fronds rather than heads.

The primary flavor compounds in dill are carvone and limonene in the seed, with d-carvone dominating. In the fronds, phellandrene is the dominant volatile. The leaf and seed smell similar but are chemically distinct - they’re not interchangeable in cooking, and dill seed in a pickle recipe specifically means mature seed, not frond tissue.

The ROI case

Fresh dill at retail runs $2.00-$4.00 per bunch (typically 0.5-1 oz), putting the price at $4.00-$8.00/lb based on USDA AMS specialty herb retail surveys. Dill seed for pickling runs $3.00-$6.00 per ounce at specialty retailers. A healthy dill plant will produce 0.25 lb of fronds across multiple harvests, plus 1-3 tablespoons of seed per plant.

The math is clearest when you’re comparing dill head cost at pickling time. Fresh dill heads at farmers markets run $1.00-$2.00 each; one tall plant produces 3-6 heads depending on management. Growing your own for a pickle run - 6 quarts of cucumbers needs roughly 6 dill heads - saves $6-$12 against a seed cost of cents per plant.

Dill self-sows freely. Let two or three plants drop seed in a bed corner and you’ll have volunteers every spring with no additional planting. In year two and beyond, your seed cost is zero.

Growing requirements

Direct sow only. Dill has a taproot that establishes immediately after germination, and transplanting sets plants back significantly - they often bolt prematurely when root-disturbed. Sow 1/4 inch deep, directly into the garden, after the last frost. Thin to 8-12 inches apart; crowded dill is weak dill.

Dill needs full sun - 6 hours minimum, more is better. In partial shade, plants get leggy, fall over, and produce sparse fronds. Soil pH of 5.5-6.5 works well. The plant is not heavy-feeding; a moderately fertile soil is adequate. Rich, high-nitrogen soil drives lush foliage growth but can reduce the aromatic oil concentration.

Plant tall varieties away from fennel (Foeniculum vulgare) - the two will cross-pollinate and the resulting seed from either parent may produce plants with muted flavor. Keep them separated by at least 50 feet if you’re growing both.

Dill tolerates drought better than most herbs once established. Once the taproot develops, the plant can handle brief dry spells without stress. During seedling establishment, consistent moisture matters.

What goes wrong

Parsley worm / black swallowtail caterpillar (Papilio polyxenes) is the most common visitor to dill. The caterpillars are green with black and yellow banding and will consume plants rapidly when populations are high. This is the larval stage of a native butterfly with ecological value. For home use, simply plant more dill than you need and accept some sharing, or hand-relocate larvae to wild carrot plants. For market production, row cover early in the season limits access.

Aphids colonize dill regularly, particularly soft new growth. A hard water spray removes most colonies. Insecticidal soap is effective for heavier infestations. Dill’s open flower umbels, once formed, attract beneficial predatory wasps (Trichogramma spp., Aphidius spp.) that reduce aphid populations over the season.

Root rot occurs in poorly drained soils or overwatered beds. Dill is more sensitive to wet feet than most garden plants once the taproot is established. Good drainage is non-negotiable.

Powdery mildew (Erysiphe heraclei) affects dill in humid conditions late in the season. By that point, the plants are usually approaching the end of their useful life anyway. Adequate spacing reduces pressure.

Harvest and storage

Harvest fronds by cutting stems above a leaf node. Don’t strip entire plants at once - leave 1/3 to 1/2 of the foliage intact at each harvest to maintain plant health. Fronds are most aromatic just as the plant begins forming flower buds; once the plant is in full flower, leaf production slows and the remaining leaves become less flavorful.

For dill heads (pickling), harvest when the majority of the florets have opened and a few seeds are forming on the outer edges of the umbel. At this stage the head is fragrant, the seeds are just setting, and the flavor is at its peak for brine applications. Use immediately or refrigerate for up to a week.

For dried dill seed, wait until the seeds turn from green to tan-brown. Cut the entire seed head, place upside down in a paper bag, and hang in a warm dry space for 1-2 weeks. Seeds will drop into the bag as they dry. Store in a sealed jar; dried seed keeps well for 2-3 years.

Fresh fronds can be frozen (chopped in ice cube trays with water) or dried, though drying loses roughly half the volatile oil content. Freezing preserves flavor better for cooked applications.

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Related crops: Cucumber, Lettuce

Related reading: Companion Planting Basics - what the evidence actually says about common pairings