Some people finish gardening in November and start again in spring. However, the garden can still reward your efforts through winter if you take some steps now.
Cutting back spent plants while the soil is still relatively dry makes sense. Compost the remnants so that the ground is ready for mulching.
Leave agapanthus, eryngium, phlomis and other plants with attractive seed heads that look especially dramatic when covered in frost, especially if next to a path. These can be enjoyed whatever the weather until they finally collapse before spring.
Divisions can be taken from large clumps. Plants can be divided into sections, each with some leaf and roots, at any time of year, but autumn is convenient. Plants divided now have a long time to survive cold, wet soil until spring, so use substantial divisions about the size of a 10cm pot. Leave the division of weaker plants until early spring, when growth is about to start.
Dividing plants is simple: clumps should be lifted and sections cut from the edge, where the growth is younger and more vigorous. Use an old kitchen knife, sharp spade or lawn edging iron. The older parts of the clump can be composted.
Vigorous perennials such as symphyotrichum (aster) and hardy geraniums soon get congested or spread further than they should and need dividing every two or three years. Many gardeners are surprised at how often plants benefit from division. Borders usually need some thinning and replanting every four years or so. Division can also be done to get more of your favourite plants.
Dig out perennial weeds such as bindweed, couch and ground elder while they are still visible. They are often deeply intertwined in infested clumps of flowers and must be thoroughly removed, even if this means lifting the whole clump.
Where it is not possible to remove every weed shoot, especially of bindweed, which often roots very deeply, cover the area with several thicknesses of cardboard disguised by a covering of bark chips or other mulch. By next autumn, the perennial weeds should be eliminated and the ground ready to be planted.
In the meantime, keep the desirable plant in a pot or spare piece of ground.
Compost bins may become overwhelmed with the sudden influx of cleared material. Consider making temporary heaps of the strawy stems from cleared borders to be added to the bins once the bin contents subside by spring.
These hummock-like heaps can be bucket-sized or large – 1.5m tall. If neatly arranged, with a teepee of poles and made of stemmy straw-like material, hummocks can be attractive in a rustic way, offering shelter to insects and other wildlife over winter.
Traditionally, gardeners lightly dig or fork borders to remove weeds and leave them tidy. A better plan is to mulch beds and borders to prevent weeds, feed the soil and limit the impact of dry weather next year. This year’s summer showed the value of mulching, delaying drought stress appreciably, so it is worth ordering in enough mulch to at least do the most vulnerable plants, including herbaceous borders and soft fruit plantations. Use nutrient-rich compost or composted manure for herbaceous areas.
Alternatively consider “chop and drop”, whereby trimmings are not composted but cut into short, 7-12cm lengths with secateurs. This rough mulch is dropped on the ground around the plants to rot where it falls, supporting worms, fungi, woodlice and other beneficial organisms. It is a simple way to recycle garden wastes, improving soil fertility without importing mulches.
The RHS is a charity inspiring everyone to grow via its research, advisory, outreach, shows and gardens. For more information, visit: rhs.org.uk