A Mexican wildflower in an Irish summer
Zinnia elegans is an annual of the daisy family from Mexico. In the wild it stays low, around 13 cm, with single purple flower heads about 5 cm across around a dark disc. Garden forms are another matter: they run from dwarfs under 15 cm to plants up to 90 cm, with double and pom-pom flowers that resemble small dahlias. The genus honours Johann Gottfried Zinn, a botanist from Germany.
What suits them here
Zinnias like warmth, sun and well-drained soil, and they will not tolerate frost. That makes Ireland a slightly challenging place, since a cool, wet summer can stall them. Some growers sow into small pots indoors in April and plant out in late May; others keep them in a polytunnel or a south-facing, sheltered bed against a wall. Seed sown straight outdoors is better left until the soil has warmed.
- Pinch out the growing tip once a seedling is about 20 to 30 cm tall for bushier plants.
- Water the soil, not the leaves, because damp foliage invites powdery mildew.
- Space plants generously for air movement in a humid summer.
- Choose mildew-resistant series such as 'Profusion'.
A cut-and-come-again flower
The more stems you pick, the more the plant produces. Cut when the flower is fully open and the stem just beneath is firm, then stand it in clean water. In the vase they hold for seven to ten days. The stems are hollow, so handle them gently, and change the water often as zinnias cloud it quickly.
Safe for pets
Zinnias are on the ASPCA's non-toxic list for dogs, cats and horses. Bees and butterflies visit the open flowers.
