Oriental poppies are spectacular and brief — enormous tissue-paper blooms up to six inches across in shades of orange, red, pink, salmon, and white, all with that characteristic dark basal blotch. They bloom hard for three to four weeks in late spring, then go completely dormant in summer, disappearing below ground until autumn when the foliage returns as a rosette.
As a cut flower, they require a trick: sear the cut stem immediately in a flame for 5–10 seconds to seal the milky sap, then condition in cold water overnight. Done correctly, they last surprisingly well. Direct sow in autumn — they need a cold period — or very early spring. They are perennial and deeply resent being transplanted; mark their location well during dormancy.
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.