Chicory is the wildflower of roadsides and old fields — its piercing sky-blue daisy flowers are open in the morning and closed by early afternoon, which dictates when you cut it. The flowers appear in succession along tall, branching stems from midsummer into autumn, the whole plant with a spare, angular, naturalistic quality that polished cut flowers cannot replicate.
Cut in the morning when the flowers are fully open — by early afternoon they close and won't reopen. The blue is a particularly useful tone, closer to true blue than almost anything else in the garden. Direct sow in spring; it self-seeds and naturalises readily in open ground.
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.
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.
Sclerotinia Head Rot
Soft brown rot on the back of the flower head, white fungal growth, and hard black bodies inside; stems may wilt and collapse.
Remove and destroy infected heads and stems. Avoid overhead watering and crowding. Rotate away from sunflowers and other susceptible crops for several years.