Calendula is the first thing to sow and often the last thing standing in the cutting garden. Direct sow in early spring — even into snow — and it germinates in cool soil and handles frost without blinking. Blooms from spring through early summer, takes a break in the worst summer heat, then often revives in fall.
The resinous orange and yellow blooms have a warm, slightly medicinal scent. As a cut flower, they are underappreciated: they last well in water, the petals are edible, and they self-seed freely so you rarely need to buy seed again.
To collect calendula for tea, harvest the flowers when they are fully open and vibrant in color, either fresh or dried. You can use the petals or the whole flower, and ensure they are clean and free from pests before using them in your tea.
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.