How to Grow Dill in Australia

Dill (Anethum graveolens) is a fast annual herb in the carrot family, Apiaceae, grown for its feathery leaves, its yellow flower heads and its seed. It grows from seed right around Australia, from a Darwin dry season to a Hobart summer. Many gardeners sow it once, then find the patch in flower before they have picked much.

Three mistakes that matter

1. Moving seedlings. Dill grows a long taproot and resents being moved, and a disturbed plant often bolts (runs to flower and seed) early. Sow where it will grow, or raise it in cells and plant out young, as Sowing Seeds describes.
2. Sowing only once. In warm weather a plant can go from seedling to flower in about seven weeks, and leaf growth stops once the flower stalk rises. Sow small amounts often instead, at the interval given in When to plant.
3. Letting the soil dry out. Hot, dry spells push dill into flower and cut the leaf harvest short. Keep the bed evenly moist from sowing to the last pick, as Care by growth stage sets out.

When to plant

Dill seed comes up in 7 to 21 days in soil of 18°C to 24°C, and more slowly in soil as cool as 10°C. It grows best in mild weather, so warm zones sow through winter and cool zones through spring and summer. Sow a short row every 2 to 4 weeks through the window rather than one long row.

At the hot end of a window, sow where plants get morning sun only and expect a shorter leaf harvest. At the cold end, wait until the last frost has passed.

Site, soil and setup

Dill wants full sun and shelter from wind, because its hollow stems snap or blow over in a gale. It does not need rich soil, only good drainage.

Container growing

Choose a pot at least 30 cm wide and 30 cm deep, which holds about 13 L and gives the taproot room. Fill it with quality potting mix, sow straight into it and thin to a few plants. Compact types suit pots best, such as 'Compatto', 'Dukat' and 'Bouquet'.

• Water: check daily in warm weather, because potting mix dries out fast and dry plants bolt.
• Feed: seaweed solution at half strength, 15 mL per 9 L, every fortnight.
• Position: full sun, out of the wind, with a short stake for any plant that leans.

Sowing Seeds

Sow dill where it is to grow, and use cells only when the seedlings can go out young.

Sowing direct

• Sow 2 to 6 mm deep and only just cover the seed, which germinates better with some light.
• Sow in rows 30 cm apart, or scatter seed over a small block so the plants support each other.
• Keep the surface moist until seedlings appear, usually in 7 to 21 days.
• Thin to 20 to 30 cm apart at 3 to 4 weeks, giving tall types such as 'Mammoth' the wider spacing.

Starting in cells

• Sow one or two seeds per cell of seed raising mix, and keep the tray warm and bright.
• Harden off (gradually accustom seedlings to sun and wind) before planting out, as hardening off seedlings describes.
• Plant out about four weeks after sowing, at 5 to 10 cm tall, without breaking up the root ball.

Care by growth stage

Steady moisture decides this crop. Dry soil sends dill to flower, while rich feeding and shade give soft, lanky stems that fall over.

Spread straw mulch around the plants once they reach 5 to 10 cm. If growth stalls in poor soil, a light dose of all-purpose controlled release granular (NPK around 14-5-10) scratched in around the plants can help.

Pinching and Harvesting

Regular picking and pinching keep a leaf crop bushy and hold off flowering for a few weeks. Heat and long days win in the end.

• Young leafy plants: pinch out the shoot tips often to encourage side growth.
• Leaf crops: cut off flower stems as soon as they appear.
• Stems for the freezer: cut whole stems just as the first flowers open, when the flavour peaks.
• Seed and pickling types: let 'Mammoth' and 'Bouquet' flower freely, since they are grown for heads and seed.
• Spent heads: cut them off before the seed drops, unless you want dill seedlings through the bed next season.

Companion planting

Dill in flower draws bees, hoverflies and small parasitic wasps, and hoverfly larvae feed on aphids in nearby crops.

Grows well with

• Broccoli and cabbage, whose aphids draw in the hoverflies that dill flowers feed.
• Cucumbers, a low vine that leaves upright dill its light.

Keep apart

• Carrots, which can lose yield growing close to dill.

Harvesting Leaves

Start picking 6 to 8 weeks from sowing, once plants stand about 30 to 40 cm tall with plenty of fine fronds.

• Snip outer fronds with scissors, holding the stem so a young plant is not pulled out.
• Leave at least a third of each plant in place to keep it growing.
• For pickling, cut whole heads once the flowers have given way to green seed and the head is still flexible.
• For dry seed, cut the heads as the seed turns from green to brown, before it drops.
• Hang seed heads upside down inside a paper bag in a warm, airy place until the seed falls.

Picked leaves keep about a week in a bag in the fridge. For longer storage, freeze sprigs, because dried leaves lose most of their flavour. Store seed only once it is completely dry, in an airtight jar in a cool, dark cupboard, for up to a year.

Add the leaves to fish, eggs, potatoes and cucumbers near the end of cooking, and use the seed in bread and pickles. Home pickles and dill kept in oil can carry botulism unless properly acidified, so follow a tested recipe and CSIRO's preserving advice.

Common problems

Seedlings fail to appear. Seed buried too deep, a surface left to dry out or cold soil can stop dill coming up. Read more

Leggy seedlings. Trays raised indoors or on a dim windowsill stretch toward the light and make weak, floppy plants. Read more

Plants wilt and die in wet soil. Dill dislikes cold, soggy ground, so plants in beds that stay wet after rain can wilt and fail. Read more

Pests and diseases

Few pests trouble dill, and aphids and powdery mildew are the ones most gardeners meet.

Carrot aphid (Cavariella aegopodii). Recorded in New South Wales, Victoria, Tasmania and Western Australia, it colonises dill, carrots, parsley and fennel. Colonies cluster on new shoots and flower stems and leave sticky honeydew. Read more

Common garden snail (Cornu aspersum). Found in every state and territory away from the tropics and deserts, it feeds mostly at night. It can destroy a row of seedlings in one sitting. Read more

Powdery mildew. A white, powdery growth spreads from the older, lower leaves over the plant, most often where plants are overwatered or crowded. Read more

Damping off (Pythium and Rhizoctonia species). These soil-borne organisms rot seed before it emerges or collapse young seedlings, mostly in crowded, humid, overwatered trays and rows. Read more

Prevention first

• Sow thinly and thin on time, so air moves between the plants.
• Water the soil rather than the leaves, in the early morning.
• Hose small aphid colonies off with a sharp spray, or use insecticidal soap on heavier ones.
• Check seedlings by torchlight on damp nights, and collect snails by day where they hide.

Tips

1. Move self-sown seedlings while they are tiny, before the taproot forms, or leave them where they come up.
2. Cook only with seed saved from your own plants or bought as a spice, because sowing seed may carry a fungicide coating.
3. Keep a pot of a compact type on a sunny windowsill for picking in cool weather.
4. Cut a few flowering stems of 'Bouquet' for a vase.