With flowers beginning to fade and seed heads ripening all around, early autumn is a perfect time to collect seeds from plants in your garden. In most cases you can store seed until spring, although some can be best sown now. Collecting seeds is a great way to save money, filling your garden with more plants or sharing them with friends.
How to collect seeds
Begin collecting as soon as you notice seed heads ripening. Seed heads usually open and change colour. Keep a look out for any special plants to make sure seeds are not being lost. Always pick a dry day to collect. If you worry about missing the seed, simply cut the seed head off early and let it fully ripen in a sunny place indoors.
Top Tip: Avoid seeds from plants labelled as F1 hybrids, mostly annuals and vegetables. They will not come true and won’t be the same as the parent plant.
Storing seed until spring
Collected seeds of many garden favourites can be stored for spring sowing. Remove any bits of the seed capsule, and pop the seeds in a labelled envelope. Then put envelopes in an airtight container and store in the fridge at about 5°c until you want to sow. Most seeds can be stored like this for two years or longer, especially if you include a sachet of silica gel to keep everything dry.
When to sow seed
Some seeds must be sown right away: plants such as magnolias and oaks have large fleshy seeds with viability that falls as they lose moisture. Some hardy annuals and perennials can also be sown in autumn for bigger plants that start flowering early next year. Direct sow outdoors (in the position you want the plants to grow) ammi, cornflowers, nigella and opium poppies. Sow aquilegia, astrantia, calendula, digitalis (foxglove) and scabiosa in pots kept in a cold frame for winter and planted out the following spring.
Many gardeners sow sweet peas from the end of this month. Sow in Seed & Cutting Compost in Visiroot Deep Cells and grow on in a well-ventilated cold greenhouse. Resulting plants will be bigger and stronger with a longer flowering period next year. Another plant to consider is delphinium, the tall, majestic spires of which fill many garden borders. Sown now, these make big strong plants that withstand better our increasingly uncertain climate. Sow in small pots indoors then pot on and pop outside in a cold frame or well-ventilated cold greenhouse, planting in spring.