Zinnia is a true Half-Hardy Annual.

It originates from Mexico, so it is a sun-worshipper that absolutely hates the cold. It completes its life cycle in one season (sow in spring, flower in summer, die in winter).

The Golden Rule: Do not rush to sow or plant these out! If Zinnia seedlings get cold or damp, they will "sulk" (stop growing and turn yellow). Wait until the soil is warm in late May or June before planting out.

Top Tip: Zinnias hate root disturbance. It is best to sow them into module cells so you can pop the whole plug into the ground without touching the roots.

These are fast-growing, satisfying seeds.

Germination:
Sow indoors in April or May. Insert the seeds vertically into moist compost. Keep warm (20-25°C). They germinate incredibly fast, often in just 3-5 days. You can direct sow outdoors in June, but they need a warm summer to flower well.

Where to Sow:
They demand full sun and a sheltered spot. They thrive in rich, well-drained soil. They hate cold, wet clay. If growing in pots, ensure good drainage and feed weekly with tomato fertiliser once they start flowering.

Care While Growing:
Pinch: When the plants are 15cm tall, pinch out the central growing tip. This encourages side shoots and turns one stem into a bushy plant with ten times the flowers.
Deadhead: Follow the stem down to the next set of leaves and snip off the dead flower to keep the plant blooming until October.

Zinnias love the heat, so pair them with other sun-loving annuals for a vibrant display:

• 🌌 Cosmos 'Sensation Mixed': Texture contrast. The ferny foliage of Cosmos softens the stiff, upright stems of the Zinnia. Plant the tall Cosmos behind the shorter 'Lilliput' Zinnias for a tiered effect.
• 💜 Alyssum 'Royal Carpet': The container partner. If growing 'Lilliput' in pots, plant purple Alyssum around the edge. The trailing habit softens the rim of the pot, and the purple contrasts beautifully with the orange and yellow zinnias.

Sow indoors in spring. Plant out in June. Flowers July to October.