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How to sow half-hardy annuals

Overview

Half-hardy annuals are quick to flower and provide a burst of colour in summer borders and pot displays. To give them as long a flowering season as possible, sow seed early so that plants have plenty of time to establish before planting out.

Once risk of frost has passed, plant your home-sown plants outside. Many varieties sown indoors by March or April will start to flower as early as June.


How to do it

Sowing half-hardy annuals: sow seeds in tray

1

Fill a tray with seed compost, then sow a tiny pinch of seeds in each cell. Cover with vermiculite, water and place the tray in a propagator in a warm spot.


Sowing half-hardy annuals: transplanting seedlings

Once seeds have sprouted, wait until two pairs of leaves form. Transplant each seedling into a 7cm pot filled with sieved multi-purpose compost.

Sowing half-hardy annuals: watering seedlings

Water well after transplanting and keep the pots in a warm, bright place. Avoid exposure to bright sunlight, which can scorch the young leaves.

Sowing half-hardy annuals: grow on until risk of frost has passed

When all risk of frost has passed, move the plants to a cold frame or patio, bringing them in at night. After a week you can plant them outside.


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