Cornflower: when to sow, plant and see it flower
Sowing, planting and flowering dates for your climate, with growing advice.
Photo: Kiran Jonnalagadda from Bangalore, India, CC BY-SA 3.0 · image resized
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 | 23 February – 21 April | 20 February – 22 May; 4 September – 3 November | 22 April – 22 May | 22 April – 3 October |
| South-west England and Wales | 12 February – 10 April | 9 February – 11 May; 20 September – 19 November | 11 April – 11 May | 11 April – 19 October |
| Midlands, northern England and Northern Ireland | 6 March – 2 May | 3 March – 2 June; 29 August – 28 October | 3 May – 2 June | 3 May – 2 October |
| Scotland | 16 March – 12 May | 13 March – 12 June; 20 August – 19 October | 13 May – 12 June | 13 May – 12 October |
| Ireland | 20 February – 18 April | 17 February – 19 May; 11 September – 10 November | 19 April – 19 May | 19 April – 10 October |
Growing
- Life cycle
- Annual (sown and in flower the same year)
- Family
- Asteraceae
- Latin name
- Centaurea cyanus
- Cold tolerance
- Hardy (withstands frost)
- Emergence
- 7–14 days
- Spacing
- 30 cm
Sources
- Aujardin.info — plant encyclopedia and bulb planting guides
- Jardiner Malin — flower and bulb fiches (same species; the lin, bleuet and lavatère pages are seed product pages, and lin is red flax)
- Gerbeaud — flower and bulb fiches (cosmos, souci, capucine, tournesol, alysse, zinnia, nigelle de Damas, coquelicot, pavot de Californie, pois de senteur, muflier, reine-marguerite, ipomée, mauve annuelle, annuelles rustiques, giroflée ravenelle, digitale, myosotis, pensée, rose trémière, pâquerette, lupin, ancolie, delphinium, échinacée, rudbeckia, gaillarde, achillée, tulipe, crocus, jacinthe, perce-neige, muscari, ail d'ornement, dahlia, glaïeul, lis, bulbes d'automne, profondeur de plantation)
- 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)
- 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)
- 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)
- Johnny's Selected Seeds — Flower Growing Guide and key growing information pages
- Promesse de Fleurs — advice pages (jacinthe read in full; the others through search-result summaries only, the pages return their navigation shell)