AS we head towards winter, trees and shrubs are providing the final flourish to their autumnal displays. Only Parrotia persica in my garden is still resplendent in its autumn livery but many native trees in the surrounding woodlands are still quite colourful. One of my favourite views on the way to work is from the bridge at Bolton Abbey. The trees along the river bank could not have been placed better by Capability Brown and in the morning sun look quite spectacular.
The berries of several trees in my garden are still giving a good show, especially now that they are no longer hidden amongst foliage. The rowans or mountain ashes especially are excellent trees for the smaller garden and many have attractive autumn tints in addition to large clusters of glossy berries. Sorbus vilmorinii is a lovely small rowan with dark pink berries gradually ageing to almost white, this year especially there has been a bumper crop of berries which in a few weeks will probably disappear as the blackbirds and thrushes gorge themselves. I also grow Sorbus koehneana, a dwarf species that produces large clusters of ivory-white berries. Both these species are easily raised from seed and every year students at Craven College will extract the seed from the berries so that it can be sown into pots and left outside for a winter chill. The cold stimulates many seeds into germinating and rowans are no exception.
The autumn colour from dogwoods was superb this year. Whilst the colourful stems are well known for brightening the winter garden from November until March many varieties can rival Japanese maples with their autumn tints. This year Cornus alba ‘Siberica’, Cornus sericea ‘Cardinal’ and Cornus sanguinea ‘Annie’s Winter Orange’ have looked especially good. Once the leaves have dropped the stems take over and at this point I tend to tidy the shrubs by removing crossing or spindly stems that might otherwise spoil the display. You can also propagate additional plants from hardwood cuttings. At both the College and Ripon Walled Garden we have now built raised timber frames which are filled with gritty compost specifically for this purpose but even a trench enriched with grit sand in the allotment can work with the cuttings inserted well into the substrate. We have also been propagating soft fruit such as black currants, red currants and gooseberries. Providing your stock plants are free from disease this is an excellent way of producing new plants. Last year’s cuttings have just been lifted and have mostly put on good root growth. They have been potted up to grow on for a year before moving into the fruit garden.
I have noticed that the recent snow fall has caused a number of branches to come down through the weight of snow, no doubt made worse because they were still in leaf. Deciduous trees can generally be pruned through the winter and so damaged branches can be removed alongside any other maintenance pruning. In some gardens larger trees may be protected by tree preservation orders and so in order to prevent a possible fine it is always worth checking first.
If you have not already done so a variety of garden shrubs benefit from winter pruning to reduce damage from snow and also wind rock. Buddleias, roses and lavatera can all be chopped back by half to prevent damage through the winter. Do not be tempted to chop back too far though, since the remaining stems protect the dormant buds from frosts, the hard prune should be left until March when the lower buds are less likely to be damaged.
Some plants may of course need more protection, pots can be insulated with bubble wrap to help prevent freezing whilst some susceptible plants in the garden can be heavily mulched. Tender plants such as dahlias are best lifted however but they will take some frost and it is best to let the foliage yellow before digging up the tubers. Students have also lifted pelagonium, fuchsia helichrysum and nepeta plants used in hanging baskets and tubs so that they can be moved into the greenhouse over winter. In spring softwood cuttings can be taken from all of these plants offering a simple and cost-effective means of propagation.
In the winter garden, heathers can provide valuable colour but in recent years the range of colours has been extended to DayGlo blues, reds and yellows. I must admit to hating these with a passion but was amused when a garden centre employee told me that every year they receive complaints from people who are concerned the display isn’t repeated in subsequent years, perhaps they need to sell top-up supplies of DayGlo glitter. Many of these heathers will find their way into winter containers alongside pansies and dwarf cyclamen but I can’t help thinking that they look a lot better without the modifications.