If you want to obtain an early flower display of annuals, there are some that can be sown in the autumn which will overwinter successfully.
Some of these hardy annuals can be sown directly in the ground, withstanding most frosts. Others are not quite so robust - they can either be direct sown and covered with cloches when frost is forecast, or they can be sown in pots and kept frost free over winter. Unless gardeners have access to a heated greenhouse half-hardy and tender annuals are best sown in spring.
Hardy annuals requiring no protection in the south
Calendula officinalis
Centaurea cyanus
Limnanthes douglasii
Linum grandiflorum
Hordeum jubatum
Nigella damascena
Lunaria annua
Papaver commutatum, P. rhoes, P. somniferum
Briza
Consolida
Hardy annuals needing some protection
Lathyrus odoratus (best sown in pots)
Eschscholtzia
Gypsophila elegans
Lavatera trimestris
Cerinthe major var. purpurascens
Salvia viridis
Matthiola longipetala subsp. bicornis
Viola x wittrockiana (pansies - best
sown in pots)
Nemophila
Adonis aestivalis
Direct sowing
Sow in September or October, when the soil is still warm. Scatter seed over a weed-free bed and cover lightly with soil or compost, or sow in drills. Dividing the bed into irregular patches with drills running in offset directions gives a more natural appearance as plants mature. Space drills 15–45cm (6-18in) apart (depending on the eventual size of the plants), sow seed and rake soil over them. Beds can be covered with fleece during cold snaps.
Protected sowing
Annuals can also be sown under cover at 18°C (64°F), reducing to 15°C (59°F) after germination. Grow them on into small plants, harden them off for overwintering in a cold frame or unheated glasshouse, and plant them out next spring.