Sweet William: when to sow, plant and see it flower
Sowing, planting and flowering dates for your climate, with growing advice.
Photo: manfredrichter, Pixabay Content License · image resized
Sown this year, this flower only blooms the following year: the flowering shown is that of an established plant.
When to sow and plant in your region
Average dates, computed from the frost dates of each climate. For your exact dates, choose your town.
| Climate | Sow under cover | Sow outdoors | Plant out | Flowering |
|---|---|---|---|---|
| South and east of England | 9 February – 21 April | 22 April – 22 August | 4 September – 3 November | 22 April – 3 October |
| South-west England and Wales | 29 January – 10 April | 11 April – 11 August | 20 September – 19 November | 11 April – 19 October |
| Midlands, northern England and Northern Ireland | 20 February – 2 May | 3 May – 2 September | 1 September – 28 October | 3 May – 2 October |
| Scotland | 2 March – 12 May | 13 May – 12 September | 1 September – 19 October | 13 May – 12 October |
| Ireland | 6 February – 18 April | 19 April – 19 August | 11 September – 10 November | 19 April – 10 October |
Growing
- Life cycle
- Biennial (flowers the year after sowing)
- Family
- Caryophyllaceae
- Latin name
- Dianthus barbatus
- Cold tolerance
- Hardy (withstands frost)
- Emergence
- 7–21 days
- Spacing
- 20 cm
Sources
- Jardiner Malin — flower and bulb fiches (same species; the lin, bleuet and lavatère pages are seed product pages, and lin is red flax)
- Royal Horticultural Society — growing guides (annuals and biennials: sowing in spring, sowing in autumn; sunflower, sweet pea, zinnia, lavatera, foxglove, lupin, hollyhock, delphinium, aquilegia, rudbeckia, achillea, tulip, daffodil, crocus, hyacinth, snowdrop, allium, dahlia, gladioli, lily, bulbs)
- RHS — Plant pages (hardiness ratings H1-H7)
- Plantura — flower portraits and planting guides (Cosmea, Kornblume, Jungfer im Grünen, Mohnblume, Flachs, Goldlack, Vergissmeinnicht, Stockrose, Silberblatt, Bartnelke, Kokardenblume, Rittersporn, Akelei, Sonnenhut, Blumenzwiebeln, Tulpen, Gladiolen)
- Johnny's Selected Seeds — Flower Growing Guide and key growing information pages
- The Old Farmer's Almanac — flower growing guides (cosmos, calendula, marigolds, nasturtiums, sunflowers, sweet alyssum, zinnias, sweet peas, snapdragons, morning glories, poppies, bachelor's buttons, foxglove, pansies, hollyhocks, lupines, columbine, delphiniums, coneflowers, black-eyed Susans, yarrow, dianthus, tulips, daffodils, crocuses, hyacinths, snowdrops, dahlias, gladiolus, lilies)
- Promesse de Fleurs — advice pages (jacinthe read in full; the others through search-result summaries only, the pages return their navigation shell)