Endive and its curly-leaved form frisée are cool-season leafy greens in the chicory family, grown as annuals for a rosette of slightly bitter leaves used in salads and, in the case of escarole, braised. Bitterness drops in cool weather and rises in heat, so timing the crop for spring and fall gives the best flavour.
Sow indoors six weeks before last frost or directly a few weeks before it, and again in midsummer for fall; set plants 8 to 12 inches apart in rich, moist soil in sun or part shade and keep them watered, because drought makes them bitter and sends them to seed. The fall crop is the better one, since the heads mature into cool weather and take light frost.
To sweeten the heart, blanch the heads two to three weeks before harvest by tying the outer leaves up over the centre or setting a plate over the plant to block the light; the inner leaves pale and mellow. Cut the whole head at the base. Slugs are the main pest, and rabbits like the young plants. Endive is a different species from the Belgian endive sold as chicons, which is forced from Cichorium intybus roots.
Lettuce Drop (Sclerotinia)
Lower leaves wilt and collapse onto the soil; a white, cottony mold forms at the crown and base, often with small black resting bodies. Plants rot at the base and die.
Remove and destroy infected plants and surrounding soil debris. Avoid overwatering and improve drainage and airflow. Rotate away from lettuce and other susceptible crops for 2–3 years. Do not compost infected material.
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.
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.
Bacterial Soft Rot
Rhizomes turn mushy and foul-smelling; foliage yellows and pulls away easily at the base. Often follows borer damage or overly wet soil.
Cut away all soft tissue back to firm rhizome, let it dry, and dust the cut with sulfur. Improve drainage and avoid burying rhizomes. Destroy badly infected plants.
Aphids
Aphididae →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.
Grey Field Slug
Deroceras reticulatum →Large irregular holes chewed in leaves, with slime trails on foliage and soil.
Hand-pick at night, set beer traps, or apply iron phosphate bait. Remove debris and mulch where they hide.