August is a good time to sown hardy annuals in the North of England, while Southern counties can sow in September. The soil is moist and warm and makes an ideal seedbed for your annuals. Sowing at this time of year produces much bigger plants as the root systems continue to grow throughout the winter and spring and so you produce an earlier, bigger, taller, more robust plant from an autumn rather than a spring sowing.
Some of these annuals can be sown directly in the ground, and will withstand most frosts. Others can be direct sown, but will need to be covered with cloches or horticultural fleece outside or kept in a greenhouse or porch in pots and kept frost-free over winter
At the moment I am collecting seeds from many of the annuals in the cutting garden and immediately sowing them back into the plot, into plastic gutters to put into the cold frame, or putting them into paper envelopes or bags and drying them for spring sowing.
This method involves sowing directly into the soil, either by broadcasting (scattering seed over the soil surface) or drilling (sowing more precisely in rows). Most of my seeds in the cutting garden are sown in drills as I want a row rather than a random mix of plants.
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, and overwinter in a cold frame or unheated glasshouse. Plant them out the following spring after gradually hardening them off.
Suitable annuals to try
- DS – Direct Sow
- C – sow under cover
- OC – Sow and overwinter in a cold frame or under a cloche or with horticultural fleece
- SS – will self seed if seedheads left on plant
Hardy annuals requiring no protection
These hardy annuals may require protection in northern parts of the UK, or even in southern parts if winter is harsh. Keep an eye on the weather, and if hard frosts are forecast, protect sowings with cloches or horticultural fleece.
- Ammi majus: Creamy white lace-like flowers in summer and ferny foliage. DS in Aug, OC in Sept
- Calendula officinalis: Single or double daisy-like flowers in shades of orange, gold, cream or yellow from summer to autumn. DS,SS
- Centaurea cyanus (cornflower): Dark blue daisy-like flowers from late spring to mid-summer. DS
- Nigella damascena (love-in-a-mist): Saucer-shaped pale blue flowers surrounded by a ruff of ferny foliage. The seed heads are decorative and can be used in flower arrangements or sprayed silver for Christmas. DS/C,SS
- Consolida (larkspur): Delphinium-like spikes of flowers in shades of pink, blue or white. I find it difficult to grow larkspur successfully – it may be that my soil is a bit too heavy and on the acid side? DS/C
- Linum grandiflorum (flax): Saucer-shaped rose-pink flowers with dark eyes in summer. DS
- Papaver commutatum, P. rhoeas, P. somniferum (corn and opium poppies): Delicate silky blooms with black centres in shades of orange, red, pink, mauve and white. If you shake the round seed heads and it rattles, the seed is ready for harvesting and sowing. DS or OC
- Lunaria annua (honesty): White or pale purple flowers in late spring and summer followed by flat, round, silvery seedpods. August is a bit late to sow Honesty, but I have bought some seeds of an usual variety and they need sowing! DS or OC
- Hordeum jubatum (squirrel tail grass): Long silky tufted flowers on grassy stems from early to mid-summer.
- Briza (quaking grass): Nodding flowers with grassy foliage.
Hardy annuals needing some protection
These hardy annuals will need some protection from frosts, even in milder parts of the UK. Cloches and horticultural fleece may be OK or keep them in a greenhouse or cold frame. Monitor water levels to make sure the seedlings are not too wet or too dry!
- Eschscholzia (Californian poppy): Cup-shaped flowers of yellow, orange, red or white in spring or summer, with ferny foliage.
- Gypsophila elegans: Clusters of numerous tiny white or pink flowers on slender stalks in summer.
- Lavatera trimestris (mallow): Cup-shaped flowers of pink or white in summer.
- Cerinthe major var. purpurascens: Deep purple bell-shaped flowers held in a cluster of dark blue bracts in summer; blue-green foliage.
- Salvia viridis (annual clary): Showy pink, purple or white leaf-like bracts in summer.
- Matthiola longipetala subsp. bicornis (night-scented stock): Pink, purple or mauve flowers in summer, strongly scented at night.
- Orlaya grandiflora: Lacy white blooms produced in summer.