September and October are ideal months for establishing new plants and shrubs in a garden. The dry hot months are over but it is still warm enough for plants to grow. A trip to the garden centre for new plants to fill gaps in borders is always a treat, but there are also several sustainable ways of producing more plants from your existing ones with very little fuss or expense.
Divide existing plants for swathes of colour
Garden designers often work with swathes of one colour to create impact in a garden. Working with this principle, if you have a much-loved perennial, plant divide it in the autumn to make more. Larger plants can be divided into several smaller plants. Indeed, many border perennials will benefit from being divided, including hostas, geraniums, lamiums, hellebores and penstemons.
Autumn is a perfect time to do this as a plant has often finished flowering, the soil is still workable and any new plants have time to set down roots before the onset of winter. Only divide a plant when it is in good health, as it will need to recover from being divided, and make sure any new plants have sufficient water to aid this recovery. If you’re not sure where to put the new plants, simply pot up and overwinter them and then use them to fill in gaps in the border the following year.
Collect and scatter seeds
Now is a perfect time to gather seeds from dried flowerheads in your garden. Aquilegia, larkspur, echinacea, poppies and love-in-the-mist are but a few likely sources. Store thoroughly dried seed in paper envelopes in a cool dark place. Alternatively, sow directly where they are to flower or in modules so that they can be transplanted at a later date – for instance biennials such as foxgloves can be sown now and overwintered so that they flower next year.
For a more relaxed approach, simply broadcast sow seed – combine very small seeds with sand or compost before scattering to ensure even coverage. Forget-me not seeds are ideal for broadcast sowing in autumn, providing a cheerful froth of blue the following May – a beautiful backdrop for spring tulips and good ground cover which will keep weeds at bay.
Some seeds will already have fallen and germinated by September time – seedlings can be spotted on closer examination of borders. These can be easily moved whilst they are small to a more desirable location, or potted up for use later.
Autumn is a prime time for taking cuttings to propagate more plants - hormone levels are high, so plants should root and grow well. Cuttings will obviously take longer to establish than plants that have been divided, but taking cuttings every spring and autumn is a good habit to form and will ensure a steady sustainable supply of healthy plants for years to come.
It is also a good insurance policy if you have half hardy plants such as penstemon and fuchsia that might not make it through the winter. Tender perennials, such as osteospermum and verbena are often used as bedding plants and discarded once they have finished flowering, but taking cuttings will provide a new crop of plants for next year and save a trip to the garden centre.
Nurturing what you have
Propagating from existing plants can be a wonderful way of observing nature and tuning into your garden across the seasons. Many gardeners will attest to the huge sense of satisfaction gained from nurturing plants from scratch and being as self-sufficient as possible.
As well as the feel-good factor, repeating favourite plants that clearly thrive in your garden conditions can also result in a natural, cohesive planting scheme that sits well with its surroundings.