December 3: Prepare for cold weather; get rhubarb ready
Barely into December and some of my trellis blew down in some very high winds that seem to be very common in Norfolk. The highlight of December for me is not Christmas Day but the 21st, the shortest day, when the evenings will then start to get lighter. Many people underestimate the importance of day length on plant growth and flowering times. Christmas is the traditional time to have poinsettias in flower; however, they will have been manipulated to flower then by adjusting the day length.
•Be prepared for much colder weather after Christmas. Having said that, it has already been much milder than last year already. Last year we were in deep snow, whereas this year we have had only one real frost so far. However, it is now important to protect the plants that are not totally hardy, such as penstemons and osteospermums. Some years these will go through the winter no problem but occasionally they get hit by a hard frost. Bracken or straw can be put down over the plants and pegged down with some twigs to stop animals disturbing it and stop it blowing away.
•Start to force rhubarb crowns now for that early start. You can use terracotta forcing pots over mature crowns for that authentic look, or use any large container such as a dustbin turned upside down over the crown to encourage an early crop of stalks.
•This may be the time of year that we are looking forward to a white Christmas and the spring following on with the potential of spring flowers. This autumn has been so mild that camellias are out in flower at Easton College. This is unusual but there are many plants in flower now, Viburnum x bodnantense 'Dawn' must be my favourite, closely followed by Clematis armandii 'Apple Blossom'. Other plants that are worth considering at this time of year are Cyclamen coum these are good indoors and outdoors, thriving in a shaded spot. Jasminum nudiflorum has masses of yellow flowers on bare stems, and this is a plant that can be wall trained for best effect. The list of December flowers would not be complete without Mahonia x media 'Charity'. This is a superb evergreen with masses of yellow flowers which are very sweetly scented.
•The winter months are the time to prune trees and shrubs which have outgrown their allotted space. Fruit trees respond particularly well to winter pruning for shape and health. Remove any material that is damaged, diseased, or dead, then prune for shape and open up the tree to help prevent fungal diseases. Shred and compost the prunings.
•The winter is the best time to prepare soil when conditions allow, as it is best to stay off the soil when it is wet. However, during dry spells it is a good time to incorporate organic matter. The soil can be left rough, as the winter frost will break the clods up.
•Should the winter turn cold and we get some snow, it will be necessary to go out and brush it off from roofs of greenhouses as it can cause them to collapse. Snow on hedges and conifers can cause them to split apart. To prevent this conifers should be tied in to help support them and snow shaken off them where possible.