Flat-leaf parsley

Sun

Full sun to partial shade; afternoon shade helps in hot summers.

Water

Keep evenly moist but not waterlogged; drought checks growth and makes leaves tougher.

Soil

Fertile, moisture-retentive but well-drained soil; tolerates slightly acidic to slightly alkaline conditions.

Height

1-2 ft (0.3-0.6 m) in leaf; flowering stems can reach 3 ft (0.9 m)

Spread

0.75-1 ft (0.23-0.3 m)

Flowers

Small greenish-yellow flowers in flat-topped clusters in early to midsummer of the second year.

Foliage

Bright to dark green, deeply divided, flat leaves on slender stalks; aromatic when crushed. Leaves may persist through mild winters but die back in severe cold.

Growth

Slow to germinate, then moderate once established.

Care needed

Low

• Pollinators
• Wildlife
• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.1 ft (0.34 m)

3. After 2 years

   1.2 ft (0.38 m)

4. After 3 years

   1.4 ft (0.42 m)

5. After 5 years

   1.5 ft (0.45 m)

   full size

About 4 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Slow

• Space plants 8-12 in (20-30 cm) apart so leaves dry readily after rain.
• Water when the soil surface begins to dry, soaking the root zone rather than wetting the foliage.
• Work compost into the soil before planting; feed container plants lightly with a balanced liquid fertilizer during active growth.
• Apply a thin mulch around established plants, keeping it away from the crown.
• Use containers at least 10-12 in (25-30 cm) deep to accommodate the taproot.

Pruning. Remove yellow or damaged leaves at their base throughout the growing season. Cut off emerging flower stalks if leaves are the priority, but replace second-year plants because removing flowers will not restore long-term leafy growth.

Start picking when plants have several well-developed leaves and are growing strongly. Cut the outer leaf stalks at soil level, choosing stalks with fully expanded leaves and leaving the central growing point intact; take no more than about one-third of the foliage at once. Leaves are best before flowering.

Early spring

Sow in deep modules under cover or directly outdoors once the soil is workable; keep the seedbed moist.

Mid-spring

Thin seedlings or plant out young plants with minimal root disturbance.

Late spring

Begin light harvesting once plants are well established.

Summer

Water regularly, harvest outer stalks and provide afternoon shade in hot climates.

Late summer

Sow a fresh batch for autumn and, in mild climates, winter picking.

Late autumn

Protect plants with a cold frame or horticultural fleece where you want to extend harvesting.

Second spring

Replace flowering plants for leaf production, or retain a few to flower for insects and seed.

• Edge vegetable beds with leafy clumps that can be harvested without disturbing neighbouring crops.
• Plant in deep pots near the kitchen alongside chives and other moisture-loving herbs.
• Use as a green filler among edible flowers and lettuces in a potager.
• Repeat small groups through mixed borders for fresh foliage, allowing a few second-year plants to add airy flower clusters.

Garden styles it suits: Potager (kitchen garden), Herb parterre, Cottage garden, Edible landscape, Sensory garden and Small-space.

Plant it with: Chives, Lettuce, Swiss chard, Calendula, Sweet alyssum and Basil.

Wildlife: Second-year flowers attract hoverflies, small bees and parasitic wasps. In North America, parsley is a food plant for black swallowtail caterpillars; leave some foliage for them where practical.

• Slow or uneven germination: use fresh seed, keep the seedbed consistently moist and allow 2-6 weeks for emergence.
• Slugs and snails: protect young seedlings, remove hiding places and use iron-phosphate bait according to its label if needed.
• Aphids: wash small colonies off with water and preserve ladybirds, hoverflies and other predators.
• Leaf spots or crown rot: remove affected foliage, improve spacing and drainage, and avoid repeatedly wetting leaves or leaving pots standing in water.

Leaves are edible for people in normal culinary amounts. Parsley contains furanocoumarins and is considered toxic to cats, dogs and horses when substantial quantities are eaten, potentially causing photosensitivity and skin injury after sun exposure. Do not offer large amounts to pets; concentrated parsley oil is not equivalent to the culinary herb and can be harmful if swallowed.

• Coriander / cilantro (Coriandrum sativum)

  Young coriander leaves usually have rounder lobes than parsley, while later leaves become finely divided. Its crushed foliage has a distinctly different scent.

• Poison hemlock (Conium maculatum)

  Mature plants are much taller, with finely divided foliage and typically purple-blotched, smooth stems. Seedlings can be difficult to distinguish;

• Fool's parsley (Aethusa cynapium)

  Usually has more finely divided, glossy leaves; flowering plants have conspicuous narrow bracts hanging beneath the small flower clusters. It is poisonous, and young plants are difficult to identify safely.

Petroselinum comes from Greek words meaning 'rock celery', while neapolitanum means 'of Naples', reflecting the association of this flat-leaved form with Italy.

Propagation. Grow from seed, preferably sown directly or in deep modules because the taproot dislikes disturbance. Sow about 0.25 in (0.5 cm) deep and keep moist; germination commonly takes 2-6 weeks. Allow selected second-year plants to set seed if you want occasional self-sown seedlings.

Accepted botanical name

Petroselinum crispum crispum Petroselinum crispum var. neapolitanum is an older name for Petroselinum crispum crispum.

Sources: GBIF (CC BY 4.0). The care and design notes are LandscapeGPT's own.