Sowing and planting
Autumn-flowering bulbs, such as autumn crocuses, Colchicum , Sternbergia , Amaryllis and Nerine, can be planted now.
Some seeds are best planted just after collection, and others may need specific climatic conditions to break dormancy (e.g. some alpines). If unsure, then sow seeds in ‘batches’, i.e. one immediately after collecting, one in winter, and one in the following spring.
Cutting back, pruning and dividing
Cutting back plants in baskets followed by feeding can encourage new growth and help revive tired displays.
Cut back delphiniums and geraniums after the first flush of flowers to encourage a second flowering period. Feed after cutting them back.
Deadhead flower borders regularly to prolong flowering. Disbud and dead-head dahlias if growing for large blooms. Leave roses that produce attractive hips.
Divide clumps of bearded iris.
Plants with a carpet-like growth habit, e.g. some alpines, can become patchy, with central areas dying off. These patches can be in-filled with gritty compost, to encourage re-growth.
Take cuttings of patio and container plants ready for next year.
Repot snowdrops if growing in containers.
Pinks and carnations that have become leggy, can be propagated by layering or by cuttings. Propagation can improve the appearance of untidy clumps.
Prop up tall perennials such as lupins, delphiniums and gladioli if staking was neglected earlier in the season.
Liquid feed containerised plants and keep well watered in dry spells.
Some late-flowering border perennials may benefit from a quick-acting feed before they come into bloom, especially if the soil is not very fertile.
Mulching borders can help retain moisture, and keep down the weeds - this will save a lot of work. A really thick layer of mulch (5-7.5cm / 2-3in all over) works best.
Most perennial weeds are best dealt with in the summer when the weeds are in active growth.
Start collecting seed from plants you want to grow next year, especially annuals such as Calendula, poppies and love-in-a-mist.
Pest and disease watch
Inspect lilies for the scarlet lily beetle whose larvae can strip plants in days. Pick off any you spot by hand.
Vine weevil can also be a problem at this time of year, particularly for plants growing in pots. There are biological controls available.
Small holes and distorted new foliage of ornamentals such as Caryopteris, fuchsias and dahlias are most likely caused by capsid bug damage.
Watch out for aphids (greeenfly and blackfly) on stems and leaves of young shoots.
Sudden collapse of apparently healthy clematis, especially the large-flowered cultivars, could indicate clematis wilt. Cut out wilted growth - new shoots may grow from ground level.
In dry weather a silvery white coating may appear on the leaves of plants such as clematis, roses and Lonicera, caused by the fungus powdery mildew. Although it's unsightly, it's not usually harmful to plants.
Look out for and treat black spot on roses and scab on Pyracantha. Remove and destroy affected leaves at the end of the season to try to reduce disease next season.