Strawflowers are the finest dried flower in the cutting garden: the papery bracts hold their vivid colour for years after drying, in red, orange, yellow, pink, white and burgundy, and the plants bloom all summer in hot, sunny spots on stems 18 to 36 inches tall. They are native to Australia and perennial only in zones 8 to 11; everywhere else they are grown as annuals.
Start seed indoors four to six weeks before last frost, pressed onto the surface since it needs light, or direct sow after frost once the soil is warm; set plants 9 to 12 inches apart in full sun and average to poor soil that drains, and water sparingly. Pinch the young plants once for more stems. They tolerate drought and heat and dislike wet feet and rich ground.
For drying, cut when the flowers are a third to half open, since they keep opening as they dry and a fully open flower shatters; strip the leaves, bundle loosely and hang upside down in a warm, dark, airy place. The stems weaken when dried, so florists wire the heads while fresh. Fresh vase life is a week, but the dried result is the point. Bees and butterflies work the open centres, and deer leave the plants alone.
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.
Botrytis (grey mould)
Grey fuzzy mould on petals and stems, worst in cool wet conditions.
Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
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.