There is a particular kind of quiet in the garden in October. The borders are thinning, the last dahlias are hanging on, and most people are putting their trowels away for the year. But this is exactly the moment I like to scatter a few packets of seed, because the flowers I sow now are the ones that open first next summer, often weeks before anything sown in spring.
Autumn sowing feels a little like writing a letter to your future self. It takes an afternoon, costs very little, and in May you will open the door to a froth of blue, white and orange that you had almost forgotten about.
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Why sow hardy annuals in autumn?
Hardy annuals are flowers that complete their life in a single year but can cope with frost. Sow them in September or October and they germinate while the soil is still warm, sit through winter as small, sturdy rosettes, and then race away the moment the days lengthen.
- Earlier flowers: autumn-sown plants usually bloom several weeks ahead of spring sowings.
- Stronger plants: roots establish over winter, so plants are bushier and need less watering in a dry spring.
- A gentler spring: one less job in the busy weeks of March and April.
- Some seeds actually prefer it: larkspur and poppies germinate better after a spell of cold.
Eight cottage garden flowers to sow now
1. Cornflower (Centaurea cyanus)
That clear, old-fashioned blue is the heart of any cottage border. Cornflowers are almost foolproof sown direct, and autumn-sown plants grow tall enough to cut for little jugs on the kitchen table. I like Cornflower ‘Blue Boy’ seeds for the truest blue.
2. Love-in-a-mist (Nigella damascena)
Soft blue flowers in a haze of feathery foliage, followed by striped seed pods that are lovely dried. Sow once and nigella will politely self-seed for years. The Mr Fothergill’s nigella mix gives you both soft blue and white.
3. Pot marigold (Calendula officinalis)
Cheerful orange and apricot daisies that bees adore. Calendula is one of the toughest annuals you can grow and often flowers right through a mild winter. Mr Fothergill’s Calendula ‘Art Shades’ has the loveliest apricot and cream tones.
4. Larkspur (Consolida ajacis)
The annual cousin of the delphinium, with tall spires in blue, pink and white. Larkspur dislikes being transplanted and germinates best after cold, so autumn is its ideal moment. Sow it exactly where you want it to flower. Mr Fothergill’s Larkspur Giant Imperial Mixed is a classic choice for cutting.
5. Bishop’s flower (Ammi majus)
Lacy white umbels that soften every colour around them, like cow parsley with better manners. Autumn-sown ammi can reach well over a metre, so give it a few twiggy supports in spring. Try Mr Fothergill’s RHS Ammi majus.
6. White lace flower (Orlaya grandiflora)
Shorter and neater than ammi, with flat white flowers edged in larger petals. It is one of the longest-flowering annuals I know and looks beautiful at the front of a border. Mr Fothergill’s RHS Orlaya grandiflora holds the RHS Award of Garden Merit.
7. Field poppy (Papaver rhoeas)
Scatter poppy seed over bare soil now and let winter do the rest. The papery flowers last only a day, but the seed heads that follow are just as pretty. For a true meadow look, common field poppy seeds (Papaver rhoeas) are hard to beat.
8. Sweet peas (Lathyrus odoratus)
Sweet peas are the classic autumn sowing, but they are best started under cover rather than direct. Sow in October or early November into deep pots, keep them somewhere cool and bright through winter, and plant out in April. Thompson & Morgan sweet pea seeds are a reliable place to start.
If you would rather not choose, a mixed packet does the work for you: the Mr Fothergill’s RHS Cottage Garden seed mix or the Pronto Wildflowers Cottage Garden mix are both easy ways to fill a bare patch with colour.
Direct sowing or under cover?
Direct sowing suits cornflowers, nigella, larkspur, poppies and calendula, especially on free-draining soil. It is the simplest method and the most cottage-like, because plants drift naturally where they fall.
Sowing under cover is the safer choice on heavy clay, in very wet or cold gardens, or where slugs are a problem. Small plants in modules or pots can sit out the worst of winter in a cold frame or mini greenhouse and go into the border in early spring. A Christow 3-tier mini greenhouse is ideal for a few trays on a patio, and the Palram Canopia lean-to grow house works well against a sunny wall if you want a little more room.
How to sow hardy annuals in autumn, step by step
- Choose your moment. Mid-September to mid-October is ideal in most of the UK. The soil should still feel warm to the touch.
- Prepare the bed. Clear weeds, rake the surface to a fine, crumbly tilth and avoid adding rich compost, as most annuals flower better on leaner soil.
- Sow thinly. Scatter seed in loose drifts or short rows, then cover lightly with sieved soil. Larger seeds such as calendula need about 1cm of cover; tiny poppy seed barely any.
- Water gently. A can with a fine rose avoids washing seed away. The HAWS Deluxe 5L watering can gives a soft, even shower that is perfect for seedbeds.
- Label everything. By March you will not remember what went where, and seedlings look surprisingly alike.
- Thin in spring, not autumn. Leave seedlings slightly crowded over winter as insurance against losses, then thin to 15–20cm apart in March.
A note on sweet peas and deep pots
Sweet peas grow long roots very quickly, so shallow trays leave them cramped. Deep, narrow pots such as Weston Mill Long Tom terracotta pots give the roots room to run, and terracotta breathes, so the compost is less likely to stay soggy through winter. Sow two or three seeds per pot, pinch out the tips once plants have three or four pairs of leaves, and keep them cool: a cold frame or unheated greenhouse is perfect, a warm windowsill is not.
Looking after autumn sowings through winter
- Watch for slugs on mild, damp evenings, when young seedlings are most vulnerable.
- Keep pots on the dry side. Cold and wet together is what kills overwintering seedlings, not frost alone.
- Ventilate cold frames and mini greenhouses on bright days to stop mould.
- Cover in a hard freeze with a sheet of horticultural fleece if temperatures drop well below zero.
Too late this year? Not quite
If October slips away from you, sweet peas can still be sown under cover into November, and poppies and larkspur can be scattered over bare soil in late winter. Everything else can wait for a spring sowing in March or April. It will simply flower a little later.
For more ideas on planning the borders these flowers will fill, The Modern Cottage Garden by Greg Loades is a lovely book to read by the fire while your seeds sit quietly under the soil.
So find an hour this week, a rake and a handful of seed packets. Next May, you will be very glad you did.
You will find all of my favourite seeds, pots and greenhouses in one place on the English Cottage Living shop page.
