Leaves are falling rapidly, and wind and rain are on the increase. Tender plants will need protecting from frost, gales and freezing rains. Move these plants into the greenhouse, or into a sheltered spot, but if you can’t, it is worth wrapping plants or pots in situ.
Sowing and planting:
Lily bulbs can still be planted in pots this month. They can either be brought inside next spring to ‘force’ them into an early display, or left outside to flower naturally in summer.
Plant tulip bulbs this month. Some tulips persist year to year, some perform less well and are treated as bedding, and replaced every year. (Click here to visit our spring flowering bulbs page.)
Now is the last chance to plant out winter bedding. You could try Cyclaman, Forget-Me-Nots, Bellis, Primula, Viola, Winter Pansies and other bedding plants. Plant them into well- prepared ground, or pots of suitable compost. (Click here to visit our autumn/winter bedding plants page.)
Cutting back, pruning and dividing:
Continue to cut down faded herbaceous perennials and add these to the compost heap.
Prune roses to prevent wind rock. (Click here to visit the RHS website and view their rose pruning pages.)
Penstemons are best left as-is (except for deadheading) until the spring, when they can be cut back further. In mild areas they can carry on flowering well into the late autumn and early winter. The old faded stems will help to protect the crowns from cold. Mulching over the crowns in colder areas will also help.
Ornamental grasses and bamboos can be cut back and tidied up at this time of year.
It is still a good time to lift and divide overgrown clumps of herbaceous perennials.
Lift and store dahlias, cannas and tuberous bedding begonias that have been hit by the first frosts.
Root cuttings can be taken now and throughout the winter. Papaver (perennial poppies), Verbascum (mullein) and Phlox are suitable examples.
In the greenhouse:
Complete cleaning out spent crops from the greenhouse if not yet done. Clean and disinfect the greenhouse structures with Jeyes Fluid or Citrox.
Make sure you have removed all shading paint from the greenhouse panes in order to maximise light levels in the darker months of the year.
Heat and/or insulation will be needed to keep the greenhouse frost free. A fan or paraffin heater should do the trick in small glasshouses. Maintaining higher temperatures will need more careful planning, and a better greenhouse heating system. Greenhouse insulation can help keep out the frost from the whole, or from a section, of the greenhouse.
Rake fallen leaves off lawns before they block out light and moisture from the grass.
Grass will continue to grow in temperatures above 5°C (41°F), so if the weather remains mild it may be necessary to trim the lawn with a mower. Ensure the cut is 3-5mm higher than in summer to prevent turf stress. On average this means a cutting height of around 4cm (1.5in).
Mowing will help to deal with any annual weeds that have sprung up in new lawns sown earlier in the autumn.
In mild parts of the country, you can still carry out autumn lawn care i.e. scarification, aeration and top dressing as long as the soil isn’t waterlogged. This will improve the lawn’s performance next year. Don’t do this in frosty weather, very wet weather or snow.
Avoid walking on lawns on frosty mornings. It can damage the grass and often leads to brown footprint-shaped marks.
It is now too late to sow grass seed but new lawns can still be laid from turf if the weather is not too cold.
Don’t feed the lawn with left-over summer feeds. These contain too much nitrogen which stimulates lush growth. Use an autumn lawn feed which contains more potassium and phosphorous to encourage hardiness and root growth instead.
It is too late to apply lawn weedkillers now as effectiveness will be much reduced.
Apply an autumn mulch to protect plants that are borderline hardy such as Agapanthus, Kniphofia and Phygelius. The plants’ own leaves, e.g. Kniphofia, can be tied up and used as protection for the crowns underneath.
Wet September and October weather will have made many clay soils unworkable until spring. In these cases mulching will help to improve and maintain soil structure.
Clear up fallen leaves – especially from lawns, ponds and flower beds.
Make sure that you have not forgotten any of your tender plants and bulbs – they need to be brought inside or into a heated greenhouse over the winter. Protect alpines from the wet if you have not done so already.
Hellebores rarely flower naturally by Christmas, despite their common name of Christmas rose. They can be encouraged to flower a little earlier, if you want, by covering them with cloches, potting them up and bringing them into a warm greenhouse, or placing them on a windowsill inside the house.
Large tubs that are at risk of cracking in the frost should be covered with bubble wrap, hessian or fleece, to insulate them over the winter.
Raise patio containers onto feet or bricks to avoid them sitting in the winter wet.
Remove stakes and other supports as final late-flowering herbaceous plants die down for the winter.
Tidy up leaves from around borders. They can be added to the compost heap, or placed in separate bins to make leafmould. Some leaves, such as plane and sycamore, are slow to break down and can delay you using your compost if you mix them into the general heap. Leafmould makes an excellent soil improver and can also be used as a seed-sowing medium.
Dig new flower beds as the weather allows. Don’t work on them when it’s very wet, as walking on sodden soil can cause compaction.
In mild weather, weeds will still appear. Hoe regularly to keep them in check.
Now can be a good time to dig up perennial weeds with long tap roots, such as dandelions and mallow, from newly cultivated areas. Clay soils, in particular, can be more workable in autumn, as they are no longer baked hard, but not yet sodden and sticky with winter wet. Mulching will help to improve the soil structure.
Pest and disease watch:
Watch out for downy mildew and black spot on winter pansies.
Check chrysanthemums regularly for signs of white rust.
Look out for crown rot and brown rots (sclerotinia) on died down perennials, especially if you are on a clay or poorly-drained soil.
Be aware that many diseases will overwinter in the soil, or on plant debris. Antirrhinum rust and Delphinium black blotch, as well as sclerotinia will lay dormant and re-infect plants when they come up the following year. It may be necessary to replant new specimens in another place if the problem is severe.
Do not feed plants this late in the season as they are no longer growing and the nutrients may be washed into rivers and streams by winter rain.
Digging the soil, especially bare patches or newly cultivated land will expose pest larvae and eggs to birds and frosts as well as clearing weeds and improving soil structure. Don’t leave soil uncovered for too long, however, as it runs the risk of erosion and washing away of valuable nutrients. Black polythene sheeting will protect it in the absence of planting or mulch.
Remember winter can be a tough time for birds in terms of water and food, so keep supplies well topped up. By putting out additional food gardeners can make a significant contribution to supporting wildlife over winter. It is also a great way to watch wildlife even in the smallest of gardens or balconies, often at very close quarters. Winter is a time to provide foodstuffs with a high fat content to help keep them warm. Feed regularly so that birds will not waste vital energy visiting your garden when there is no food. Aim to carry out these tasks from late autumn (or as soon as hard frosts arrive) until mid-spring. Place fat blocks in wire cages. Balls in plastic nets are not recommended as birds such as woodpeckers can get their tongues caught. You can create your own fat blocks by melting suet into moulds such as coconut shells or logs with holes drilled in.
Check bonfires before they are lit for sheltering and hibernating animals, such as hedgehogs, toads and frogs.
Melt a hole in the ice on ponds to allow the wildlife to drink, and enter and exit the water. Fill a sauce pan with hot water and sit it on the ice until a hole has been melted. Do not hit or crack ice as this can send shockwaves through the water that harms wildlife.
Provide a shallow dish or container of water at ground level. This will benefit other garden wildlife that needs to drink, as well as birds.
Make an insect or bug hotel and put up in a sheltered position. Overwintering ladybirds and lacewings will find this useful.
In late winter, clean out bird boxes so they are ready for new nests in spring.
Leave healthy herbaceous and hollow-stemmed plants unpruned until early spring. These can provide homes for overwintering insects.