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How to grow summer bedding from seed


Raising summer bedding plants from seed is easy, it saves you money and greatly extends the range of plant varieties you can grow.

The secret of germinating summer bedding seeds is a plentiful supply of warmth and light. Most seeds need a steady heat of 18-21°C to germinate, so do consider investing in a heated propagator to maintain a constant temperature through March and April.

How to do it


Fill pots with seed compost, tap to settle, and lightly press the surface with the base of a pot. Space your seeds evenly over the compost.


Cover seeds thinly with fine, sieved compost, or use a layer of vermiculite, a sterile material perfect for covering seeds.


Germination rates vary between varieties. Wait until the seedlings are well developed with good roots before pricking out.


Handle seedlings by their first leaves to avoid crushing the stem and plant individually into pots of seed compost.


By late May or early June, late frosts should have passed and outdoor conditions will be warm enough to plant your bedding into their final position outside for a bright summer display.

Our tip

Sow in small pots which are more convenient than seed trays to grow a wide range of plants in a small heated propagator.

Sow seed sparingly over several pots rather than put too many in one. Seed quantities can vary from one packet to another, and one pack may contain too many for a single pot.

Water seedlings regularly in order to avoid compost drying out and after 4-6 weeks add a weekly liquid feed using a general fertiliser to promote strong and healthy growth.

Discuss this project

Talkback: How to grow summer bedding from seed
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Rosemary Clarke 14/03/2013 at 23:38

When should the Cosmos seedling be pinched out? Mine are now quite "leggy" @ 3-4 inches but seem only to have 1 pair of leaves.

Busy-Lizzie 15/03/2013 at 09:12

I think you probably sowed them a little early and there still isn't enough light. Pinch them out when they get another set of leaves. Still plenty of time to sow more, days are lengthening now.

sotongeoff 15/03/2013 at 10:30

Is this pinched out or pricked out I wonder?

If you bury the stems slightly deeper in the compost when you prick them out that overcomes some of the leggyness-you can do this for some seedlings- but not all