How to sow zinnia seeds indoors

By sowing zinnia seeds early in the year, you can enjoy riotous colour from midsummer until the first frosts.

Zinnias also make beautiful cut flowers. Try growing other cut flowers from seed to ensure you have an abundant supply of flowers for the house.

Don't worry if you don't manage to sow them indoors by April – zinnias can be sown outdoors in May and June.

Learn how to sow zinnia seeds indoors by following our four simple steps, below.

You Will Need

• Seed compost
• Zinnia seeds
• Seed tray or small pots
• Vermiculite

Step 1

Fill small plastic pots or a seed tray with seed compost and water it gently. Place the seed on the damp compost, allowing around eight seeds per 9cm pot.

Step 2

Lightly firm the seeds in place using the base of an empty pot, then cover the seeds with a fine layer of vermiculite, horticultural sand or more seed compost.

Step 3

Water the pot of seeds carefully and allow excess water to drain off before placing pots or trays on a warm windowsill or in a heated propagator at 20-25°C.

Step 4

Prick out seedlings when they’ve formed two pairs of leaves, growing on in their own pot. Harden off and plant out 30cm apart when all risk of frost has passed.

Planting out your zinnias

When planting out your zinnias, choose a site for them that is sunny and sheltered, and plant them in well-drained soil.