Tip of the month: October
Autumn sowing – is it worth the gamble?
By sowing certain vegetable and flowers now you can get earlier rewards next year, says Alan Titchmarsh
Autumn sowing of hardy flowers and veg directly outside in the garden is a traditional technique that has fallen out of favour in recent years. Perhaps it’s the long wait between sowing and harvesting, or the fact that you’re pinning your hopes on the fickle British winter weather, or just the fact that you can buy ready-grown plants from garden retailers during spring without all the fuss of raising them yourself? But autumn sowing is cheap, easy and can produce earlier harvests just when you need them most. By sowing now, the soil conditions are perfect for quick germination producing sturdy seedlings that can survive the winter unscathed. This is a real advantage if you have heavy soil which is slow to warm up in spring – delaying spring sowings. Perhaps the best thing about sowing in autumn is that you can’t lose - if disaster strikes and a crop fails, you can always try again in spring. So if you have some suitable seed left over…have a flutter on the gardening lottery, by sowing now.
Tools for the job
What’s worth sowing now?
- Peas and broad beans for a May harvest
- Hardy annuals sown outdoors for early flowers
- Half-hardy annuals in pots in a greenhouse
- Hardy perennials for flowers in their first year
- Sweetpeas for flowers by May
Hardy annuals If the weather and soil conditions allow, there is still time to sow a wide range of hardy annuals during early October to get flowering plants by late spring. Early blooms from old favourites, including calendula, candytuft, cornflowers, larkspur and nigella, will provide colour and interest to help bridge the gap between the last of the spring bedding and the first of the summer displays. Sow them now in any well-prepared soil in sun, that’s been weeded and cultivated into a fine tilth. Cover with open cloches to achieve quick germination and establishment before the onset of winter.
Sweetpeas If you are going to experiment with just one autumn sowing, try sweetpeas. This popular hardy annual can be sown indoors or out in autumn or spring. Outside, sowings made now should be in flower by the end of May – stealing a march on spring sowings that are made in early April. Under cover, sow during February or early March for the earliest flowers. Since sweetpea seeds have a very hard seedcoat, they need special treatment to ensure speedy germination. First soak them in water for 24 hours, those that swell can be sown directly, but those that do not will need their tough seedcoat ‘chipped’. Simply, use a sharp knife to remove a sliver of seed coat on the opposite side of the seed to the ‘eye’. Outside, sow 2-3cm deep in well-prepared soil, spacing them 20-30cm apart. Autumn sowings will benefit from cloche protection to encourage germination and help protect young plants from the worst of the winter weather. Indoors, sow seed in special root-trainer or long-pots (or the cardboard cores of toilet rolls), filled with fresh sowing compost. Sow three seeds per pot, in 2cm-deep holes made with a pencil. Cover and water well then germinate on a warm windowsill or in a heated propagator. Move the seedlings to a coldframe or unheated greenhouse as soon as they emerge and keep well ventilated on mild days. Be prepared to protect the plants if hard frosts are forecast by insulating the coldframe with a piece of old carpet, garden fleece or bubble polythene.
Half-hardy annuals These are not fully hardy so will not survive sowing outside at this time of year. Instead, sow now in cellular seedtrays or small pots in a well-lit frost-free place, such as greenhouse, conservatory or even a kitchen windowsill. The resulting plants should be ready for planting out after the last frosts of spring and should flower up to a month earlier than spring-sown plants.
Hardy perennials Most hardy perennials can be raised from seed, including Aquilegia, Delphinium, Geum, Echinops, Gaillardia, Heuchera and Liatris. The beauty of sowing hardy perennials in autumn is that you can get flowering plants in their first year, whereas spring-sown plants will take a further year or even two to reach maturity. There is still time to sow hardy perennials now, in pots of fresh sowing compost, placing them in a coldframe or under a cloche in a sheltered, shady part of the garden. Prick out into individual pots or cellular trays next month, so they have time to get established before winter. Then during early spring ventilate the coldframe to start hardening off the young plants. By April they should be ready for planting out in their flowering position.
Hardy peas and beans Sowing peas and beans in autumn allows you to harvest up to a month earlier than spring-sown crops. If space is at a premium, an earlier harvest means you can get two crops off a single patch of soil in the same season. Broad beans, such as ‘Aquadulce Claudia’, are very hardy and can be relied on to survive even severe winters provided they are sown in well-drained soil. Peas, on the other hand, are more of a gamble especially in cold or wet winters. They are also more prone to pest and disease attack over the winter months. This year grow the tried and tested ‘Feltham First’, and experiment with ‘Oregon Sugar Snap’ for an early crop of mangetout peas. The key to success, with both peas and beans, is to sow while the soil is relatively warm (above 7oC) - which means sowing by mid-October in most areas. Quick germination produces sturdy seedlings that are better able to cope with the harsh winter weather. However, be prepared to cover the seedlings with cloches or garden fleece to protect them from severe frost and penetrating winds. If soil conditions are unfavourable or your garden particularly exposed, you can also sow broad beans in seedtrays or pots. Protect them in a cold porch, greenhouse or coldframe over the winter months and they’ll be ready for plating out in the New Year. With luck, by May, you’ll have a bumper harvest - several weeks earlier than spring-sown crops.