How to grow annual flowers from seed
Annual flowers are easy to grow from seed. We show you how.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
At its best | yes | yes | yes | |||||||||
To do | yes |
It's easy to succeed with annual flowers. Follow your seed packet's instructions but use your own judgement, too. Sowing temperatures vary between varieties; it's roughly 18-24 degrees celsius for half-hardy annuals and 8-16 degrees celsius for hardy annuals. Use clean pots or trays, and start a new bag of multi-purpose compost. Hardy annuals often resent root disturbance so if you sow these indoors, sow them in cells that can then be transplanted without disturbing the rootball.
You Will Need
- Seeds
- Seed tray or small pots
- Multi-purpose, peat-free compost
- Pea sticks
- Secateurs
Step 1
When seedlings have their first true leaves, carefully prick them out into small individual pots or seed trays. Grow on in warmth for a few days, then move to a cooler windowsill.
Step 2
Direct sun is essential. Warmth-loving/delicate kinds are best on a patio; traditional hardy annuals thrive in the open garden. In a poor summer or cold location, salpiglossis, eustoma or large-flowered zinnias do best under glass or in a polytunnel.
Step 3
Annuals need fertile soil enriched with a little well-rotted compost and general fertiliser, such as blood, fish and bone. Use a multi-purpose compost for containers, and apply liquid tomato feed weekly from June onwards.
Step 4
Cut flowers need straight stems, so support is essential for taller species. Use pea sticks to provide support and tie plants to them where necessary.
Step 5
Unless you cut all annual flowers as they grow, you must remove spent blooms to prevent plants setting seed - otherwise they'll stop flowering. Snip off fading flower-heads regularly to promote a fresh flush of buds.
Festive subscription offer
Save 51% on the shop price. Subscribe to BBC Gardeners' World Magazine today and get 6 months of free seeds for Spring 2025.
Year Planner 2025 on sale
Starting to plan your gardening year? The Year Planner 2025 is packed with expert advice from the Gardeners’ World team, to ensure you have your best gardening year yet.
Discover our new digital travel brochure
Whether it's a thrilling Arctic cruise or a charming getaway to historic Bath, our NEW travel brochure has exciting options for everyone.
Discover Dangerous Plants
From witchcraft to murder mysteries, uncover the power of plants in the new BBC Gardeners' World Magazine podcast series.