Clear whites to look for
White zinnias are a deliberate selection from a species that is naturally purple. Named whites include 'Crystal White', 'Purity' and 'Profusion White', with the last coming from a series bred for resistance to mildew. Some whites have a green or yellow eye, and cream forms exist too. In the language of flowers, white suggests purity and goodwill, so the flowers can be used for christenings and weddings in late summer.
Why disease resistance matters in Ireland
Powdery mildew is the standard zinnia problem in humid weather, and Irish summers can be humid. Mildew shows up clearly on white petals and leaves as a grey-white coating, which makes it doubly annoying. Picking a resistant series and giving plants space solves most of it.
- Sow indoors in April in small pots with some bottom warmth.
- Plant out in late May, 25 to 30 cm apart, in full sun.
- Water at the base of the plant in the morning.
- Take off faded heads promptly to keep the plant tidy.
Mixing white with other flowers
A white zinnia is a useful link between strong colours. Pair it with dahlias, cosmos and ornamental grasses in a late summer bunch. Used alone in a tall jar, a single colour looks calm and contemporary.
From garden to vase
Pick in the cool of the morning, once the stem is stiff just under the head, and remove the lower leaves. Expect a week to ten days of vase life, with the water changed every second day.
Pet safety
The ASPCA lists zinnia as non-toxic to cats, dogs and horses.
