How to Grow Parsley in Australia

Parsley (Petroselinum crispum) is a herb in the carrot family, Apiaceae, grown for its leaves and, in the Hamburg type, for a parsnip-like root. It grows in every Australian climate zone, from a Darwin dry season to a Hobart summer, and one plant can be picked for months. Most failures start at sowing, because the seed is slow and gardeners give up on it.

Three mistakes that matter

1. Letting the seedbed dry out. Parsley seed is slow to come up, and a surface that dries out during that wait can lose the whole sowing. Keep it moist until seedlings show, as Sowing Seeds describes.
2. Picking from the top. A stem that loses its leafy tip does not reshoot, so tipping the plant leaves bare stalks. Cut whole outer stems at the base instead, as Harvesting Leaves describes.
3. Keeping plants too long. Parsley is a biennial (it flowers in its second season), and once the flower stalk rises the leaves turn tough and bitter. Pull plants that keep flowering after their stalks are cut, and follow the timing in When to plant.

When to plant

Parsley seed germinates in soil from about 10°C to 30°C, and comes up slowly and unevenly in cold, wet ground. Most zones have a long window, so sow a second batch while older plants are still cropping, ready to take over when they flower.

At the hot end of a window, sow where plants get some shade and check the seedbed daily. At the cold end, a light frost does little harm once plants are established.

Site, soil and setup

Choose a spot with at least three hours of sun, and more for flat-leaf types. Parsley likes rich, moist soil that still drains freely, because roots rot in soil that stays wet.

Container growing

Choose a pot at least 25 cm wide and 25 cm deep, which holds about 8 L. Fill it with quality potting mix and sow straight into it. Curled types such as 'Moss Curled' and 'Triple Curl' stay compact and suit pots best. Keep Hamburg parsley in a deep garden bed.

• Water: check the mix daily in warm weather and keep it evenly moist, because pots dry out fast.
• Feed: fish and seaweed blend at half strength, about 12 mL per 9 L, every fortnight.
• Position: at least three hours of sun, moved into shade during hot, sunny spells.

Sowing Seeds

Sow parsley where it will grow, or raise it in cells and plant out young, taking care of the taproot.

Sowing direct

• Soak untreated seed in water overnight before sowing to help it along.
• Sow 3 to 10 mm deep in rows 30 cm apart.
• Keep the surface moist until seedlings appear, usually in 2 to 5 weeks.
• Thin to 20 to 30 cm apart, and add the thinnings to salads.

Starting in cells

• Sow two or three seeds per cell of seed raising mix, and keep the tray warm, bright and moist.
• Harden off (gradually accustom seedlings to sun and wind), as hardening off seedlings describes.
• Plant out at 5 to 10 cm tall, before roots circle the cell, without breaking the root ball.

Some seed, such as 'Midori', carries a fungicide coating and is for sowing only: never eat it or feed it to animals. Sow it dry, without the overnight soak, and read its packet first. Wear gloves to handle it, wash your hands afterwards, and keep it away from children and pets.

Care by growth stage

Steady moisture decides this crop. Dry soil sends parsley to seed and makes the leaves stringy and bitter, while leaves kept wet at night invite leaf spot.

Mulch with straw once seedlings stand 5 to 10 cm tall. Parsley in well-composted ground needs little feeding, so keep every feed at half strength. 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

Removing flower stalks holds off the end of the harvest for a while.

• Flower stalks: cut them out as soon as they appear, down at the base.
• Yellowing leaves: snip off lower leaves that turn yellow, which keeps the plant tidy and prompts new growth.
• Tired curled plants: cut the whole plant back hard; it can reshoot from its fleshy root for another six months or so.
• Flat-leaf in flower: leave one plant to seed, shake the heads where you want new plants, then pull it out.

Companion planting

Parsley left to flower draws lacewings, hoverflies and ladybirds, whose young feed on aphids and other sap suckers.

Grows well with

• Tomatoes, which gain from the aphid eaters that flowering parsley brings in.
• Chives, a slim, upright clump that leaves low parsley its light.

Keep apart

• Carrots and celery, which share parsley's diseases, aphids and viruses.
• Dill, another host of those aphids and the viruses they spread.

Harvesting Leaves

Start picking about 10 to 12 weeks after sowing, once the plant has a full ring of strong stalks.

• Cut outer stems right down at the base with scissors.
• Work from the outside in, leaving the young centre stems to grow on.
• Pick often: regular cutting keeps new leaves coming.
• Lift Hamburg roots with a fork from about 85 to 95 days, or leave them in the ground and dig as needed.

Wash picked leaves, let them drip dry and keep them in a plastic bag in the fridge. For longer storage, freeze chopped leaves in ice cube trays topped up with water. Dried parsley keeps, but it has much less flavour than fresh.

Use the leaves and stems in salads, sauces, casseroles and stews, and cook Hamburg roots as a vegetable.

Common problems

Seed fails to come up. Seed over a season or two old, seed sown too deep, a surface left to dry out or cold, wet soil are the usual causes. Read more

Plants flower in their first season. Dry soil makes parsley bolt (run to flower and seed) early, so the first remedy is steady watering, as Care by growth stage sets out.

Seedlings stall after planting out. Seedlings left too long in cells wrap their roots around the cell, and a damaged taproot sets plants back. Read more

Pests and diseases

Wet leaves spread parsley's leaf diseases, and wet soil brings on its root rots.

Septoria leaf spot (Septoria petroselini). The most common leaf disease of parsley in Australia, it makes small tan spots with dark red-brown edges and black dots. It spreads by splashing water on wet leaves. Pick off and bin spotted leaves as soon as they appear.

Alternaria leaf blight (Alternaria petroselini). Brown to black patches start at the leaf edges, then whole leaves yellow, brown and collapse. It thrives in hot, rainy, humid weather and has caused severe crop losses in Queensland. Pull out badly blighted plants and sow the next crop in a fresh bed.

Root rot and damping off (Pythium and Phytophthora species). Seedlings collapse, and older plants wilt fast over brown, spongy roots. It strikes in cold, wet winter soil in the south and warm, wet weather in Queensland. Pull out collapsed plants and ease off watering. Read more

Carrot aphid (Cavariella aegopodii). Recorded in New South Wales, Victoria, Tasmania and Western Australia, it feeds on parsley, carrots, dill and celery. Aphids also spread viruses that leave young leaves mottled and older leaflets twisted. Hose small colonies off with a sharp spray. Read more

Common garden snail (Cornu aspersum). Found in every state and territory away from the tropics and deserts, it eats parsley seedlings and soft leaves. Collect snails at dusk and after rain. Read more

Root-knot nematode (Meloidogyne hapla and M. incognita). These soil worms raise galls on the taproot, leaving plants stunted, yellow and wilting in the heat. Recorded on parsley in New South Wales and Queensland, they are worst in sandy soils like those of south-west Western Australia. Grow the next sowing in a different bed. Read more

Prevention first

• Water in the morning, at soil level where you can, so leaves dry before night.
• Space plants so air moves between them.
• Sow fresh seed from a reputable source, because leaf spot and leaf blight can travel on seed.
• Pull out old parsley and carrot-family weeds, which carry viruses to new plants.

Tips

1. Sow a few radish seeds along a parsley row: they come up quickly and mark the row while the parsley is still hidden.
2. Collect seed from curled parsley and sow it in trays, since curled types rarely self-sow.
3. Pick only parsley you know you sowed. Hemlock (Conium maculatum), a highly toxic weed also called poison parsley, grows 1 to 2.5 m tall with purple-spotted stems and white flowers.
4. Mitsuba, sold as Japanese wild parsley, is a different plant (Cryptotaenia japonica) with three-part leaves.