Germination temperature
Cool soil; seed sprouts in about 10 days at 16 °C (60 °F).
Herb growing guide
Chervil is a delicate, parsley-like herb with a mild aniseed taste that grows fast in cool weather and bolts quickly in heat. Sow fresh seed where it is to grow, keep it cool and moist, and resow every few weeks.
Cool soil; seed sprouts in about 10 days at 16 °C (60 °F).
On the surface or very lightly covered, up to about 1 cm (1/2 in).
About 5-10 days indoors; up to three weeks outdoors in cool soil.
Light helps germination, so cover only thinly.
None; use seed less than a year old.
Direct sow. Seedlings form a taproot and transplant poorly.
Freshness is the key. Chervil seed stays viable for only about a year, and home-saved seed does not store well, so sow it within a year of harvest. Old seed is the most common reason for an empty row.
Not needed. The thin, narrow seed takes up water easily.
Not needed for spring sowing. In cold-winter areas, seed sown in late autumn lies over winter and comes up the following spring, which is a natural way to get an early crop.
Not needed. What helps is keeping the lightly covered seed constantly moist, for example by misting or laying newspaper or damp sacking over the row until seedlings appear.
Chervil is a cool-season herb. UC Master Gardeners report germination in about 10 days at a soil temperature of 16 °C (60 °F). Outdoors in cool spring soil it can take up to three weeks. Warm conditions do not stop germination outright, but they make the young plants bolt quickly.
Sources differ. University of Illinois Extension says light helps the seed sprout and advises covering it very thinly or not at all; RHS sows in drills about 1 cm (1/2 in) deep. A good compromise is to press the seed onto the surface and cover it with a few millimetres of fine compost or vermiculite.
Fine, moist, well-drained soil with organic matter. Chervil does best where the soil stays cool, such as beside taller plants or under light shade.
Keep the surface moist at all times. Because the seed is barely covered, it dries out fast in sun or wind.
Light helps germination, which is why deep sowing fails. After emergence, chervil prefers bright light without strong afternoon sun.
About 5-10 days when started indoors; outdoor sowings may take up to three weeks depending on temperature.
Direct sowing is strongly preferred because chervil develops a taproot and seedlings are difficult to transplant. If you start seed in modules, plant out at about 5 cm (2 in) tall, before the taproot develops, at the same depth and without disturbing the roots.
Thin seedlings to about 15 cm (6 in) apart in rows 30 cm (12 in) apart; UC Master Gardeners suggest up to 30 cm (12 in) between plants. Water regularly from the start, because uneven moisture is a trigger for early flowering.
Cause: seed more than a year old, seed buried too deep, or a dry surface. Fix: buy or save fresh seed each season, cover only thinly, and keep the row moist under newspaper or sacking until emergence.
Cause: bolting in hot, dry weather or with irregular watering. Fix: sow in the cool season, give light shade in summer, keep the soil evenly moist, and sow again every 3-4 weeks.
Cause: once flowers appear, leaf flavour and texture decline. Fix: pick leaves young and keep a new sowing coming on.
Cause: aphids, the main pest RHS lists for chervil. Fix: check leaf undersides, rinse off small colonies, and pick affected shoots.
Chervil is easiest in the cooler months. In the Indian plains, sow from the end of the monsoon through winter; in the hills, spring and late-summer sowings do well. In temperate climates, sow from spring to late summer.
Because each sowing crops for only a few weeks before bolting, resow every 3-4 weeks for a continuous supply.
Leaves are ready roughly eight weeks after sowing, once plants are at least 10 cm (4 in) tall. Pick a few leaves per plant, or cut stems back to 5-7.5 cm (2-3 in) to let them regrow.
Chervil loses much of its flavour when dried or cooked for long. Add it to dishes just before serving.
Sow fresh chervil seed in the cool season for tender, aniseed-scented leaves.
Light helps. University of Illinois Extension advises covering the seed very thinly or not at all, while RHS sows about 1 cm (1/2 in) deep. A few millimetres of fine compost is a safe middle ground; never bury it deeply.
Only about a year. Sow fresh seed each season; older seed often germinates poorly.
Warm weather and inconsistent watering push chervil into flower quickly. Grow it in the cool season or in light shade, keep the soil evenly moist, and sow every 3-4 weeks.