How to grow Zinnia

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Seed Sowing

Don’t sow too early as Zinnia do not like the cold and prefer not to have their roots disturbed. Ideally direct sow in the soil around Mid-May or in modules from April. Sow into drills 30cm apart and thin to 5cm in the row. Make sure the beds have a fine tilth and are weed free.

Transplanting

If sowing in modules, transplant outside once seedlings are established around mid-May, spacing 30cm apart. Zinnias can also be grown in containers.

Plant Care

Keep the area weed-free and watered during hot spells. You can mulch around the plants to keep in moisture and prevent weeds. Deadhead to prolong flowering. Stems may need support, especially in windy growing conditions.

Challenges

Zinnia are generally pest and disease-free but can be prone to powdery mildew or bacterial wilt. Make sure to use the recommended spacing and not-overwater to keep the plants happy and less vulnerable to aphids and spider mites.

Harvest

Pick the flowers often to encourage more flowers to form; they will usually flower for around 10-12 weeks. Ideally harvest the flowers in the morning when temperatures are low and plant water content is high. Plants will arrange better if left to sit in water for a few hours after cutting.

Culinary Ideas

Zinnia petals are edible and make a delightful addition to salads, desserts or ice cubes with their pop of colour and delicate feathery forms.

Seed Saving

Harvest the individual flowers as they dry or whole plants once most of the flowers on the stem have dried. Lay out on a sheet to dry further and thresh by hand and winnow to clean the seeds.

Zinnias are cross-pollinated by insects with other varieties if grown together. If growing for seed make sure to keep varieties separate to ensure the characteristics of your saved seed will be true to type.

Store in a cool dark place; seeds should remain viable for up to 5 years.

Varieties