Zinnia's are mostly annual plants, popular because of the colourful, daisy-like flowers. Native to Mexico, there are 18 species and hundreds of cultivated forms, which are grown as annual bedding plants. Flowers come in vivid colours from red, orange and deep pink to green, with a lovely long flowering season from summer to the first frosts. Zinnias are perfect for filling gaps in the border and also work well in container displays. Long stemmed varieties make great cut flowers and single-flowered varieties are attractive to pollinating insects.

Sow seeds from March and April in individual pots or module trays of moist seed compost and cover seeds with a very fine sprinkling of compost or vermiculite. Place container in a propagator or warm place, and keep at a temperature of between 20-25C. After sowing, do not exclude light as this helps germination. Keep the surface of the compost moist but not waterlogged. When well grown, gradually acclimatise young plants to outdoor conditions for a few weeks before planting out after all risk of frost, 20-30cm apart, taking care not to damage the root system.

Zinnia can also be sown outside in May once the soil has warmed, 3mm deep in drills 30cm apart in well-cultivated soil which has been raked to a fine tilth. When large enough to handle, thin out seedlings to 20cm apart.