Chervil is the most delicate of the fines herbes — lacy, fern-like leaves with a subtle anise flavour that disappears with heat, so it is always added at the very end of cooking or used raw. It thrives in cool weather and goes to seed quickly once temperatures climb above 70°F. Sow in early spring and again in late summer for a fall crop.
One of the best shade-tolerant herbs: it genuinely prefers dappled light to full sun, making it useful under taller plants. Direct sow only — it develops a taproot and dislikes transplanting. Self-seeds freely once established.
Damping Off
Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.
Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.
Downy mildew
Yellowing on top of leaves with grey-purple fuzz underneath. Spreads rapidly in humid conditions.
Remove affected leaves. Improve air circulation. Avoid overhead watering. Copper spray as preventive.
Aphids
Clusters of small soft insects on new growth and flower buds.
Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.