December in the garden

Try and finish off any winter digging this month and don’t forget to mulch your beds with a good layer of compost, leaf mould or rotted farmyard manure. Alternatively, sow a green manure crop on vacant beds. All these methods help encourage good soil fertility and texture as well as preventing weed growth which can harbour pests and diseases over the winter period. A great way to burn off some of the Christmas excess is to turn your compost heaps over. This will help the heap generate more heat and decompose rotting material more quickly; make sure heaps are covered with old carpet, thick black polythene or other suitable material that will keep the heat in and the rain out.

As the year draws to a close, take time out on a fine day to walk around your plot and make notes of what has succeeded this year, what didn’t crop too well and what changes you’d like to make next year. This is a great time to build new vegetable beds or create fruit-growing areas and to work out your crop rotation plan for next year, especially as all the seed catalogues are out now.

Maintenance

Remove any remaining damaged or rotted fruit from bushes and trees on the plant itself and any on the ground. Take the opportunity to remove dead, diseased or dying branches and stems from top fruit trees at the same time and put grease bands around fruit trees to prevent moths from laying eggs in the bark over the winter. Mulch around the base of fruit trees and bushes, taking care not to let the mulch touch any stems or trunks. There’s still time, until March, to plant any new bare-rooted fruit canes, bushes and trees but not when the ground is frozen.

Increase your stock of soft fruit like currants and gooseberries by taking hardwood cuttings. Choose stems where wood has had a full growing season and cut each shoot at the base of the current season’s growth. Trim off the tip then cut into 20cm/8 inch sections, straight across at the base below a bud. Bundle together, label and either put into a pot with gritty loam based compost and over-winter in a cold frame or put in a slit trench in a spare corner of the vegetable plot. Two-thirds of the cutting needs to be below compost/soil level. Roots should form between six and 12 months. Keep cuttings watered.

If bad weather prevents you working outside now’s a good time to plan your plots for next year, making sure you rotate crops to control the build-up of pests and diseases. Rotations are usually based around plant families and to gain the most benefit, leave at least three years between growing crops from the same family in the same area of ground again. Green manures are an alternative to mulching beds in winter and are great for increasing organic matter levels in the soil.

Order seed catalogues if you haven’t already and plan to grow something different and unusual next year for a change. There are many alternative seed catalogues around now offering different crops to grow from Europe or try heritage varieties of familiar vegetables. Use resistant varieties for susceptible vegetables to control pests and diseases such as mildew in lettuce, bolting in onions, lettuce and leeks, and root fly in carrots. Choose dwarf varieties of vegetables if your garden is exposed to winds.

Some good housekeeping in the tool shed is needed at this quiet time of the year. Clean gardening tools and equipment, including your boots and wellies, wash out pots, throw out old compost and generally tidy up the shed; soil borne pests and diseases can carry to all these areas so it is important to eliminate any hiding places for them. Extend the clean up to outside and clear paths of debris and weeds, and tidy up around compost areas. Keep an eye out for hibernating hedgehogs, though, in wood and leaf piles and do not disturb them.

Harvesting

  • Remove any rotting, diseased or damaged plants from crops still left in the ground. Root vegetables can be harvested as required or harvest the whole crop and cover with a thick layer of straw or bury in a shallow trench until needed. Celery can be lifted now or covered with straw in situ until required.
  • Harvest winter lettuce, either picking young leaves or cutting the whole plant when mature.
  • Brussels are ready for harvesting; pick the buttons as soon as they are large enough and earth up or stake stems of tall varieties for stability from winter winds
  • Spring cabbages planted in autumn can be harvested now as greens. Brussels are ready for harvesting; pick the buttons as soon as they are large enough. Earth up stems of tall varieties for stability from winter winds.

Sowing

Garlic, shallots and onion sets and broad beans can still be planted in milder areas.  

Philippa Pearson

Philippa Pearson is a professional horticulturist and gardener, and she looks after a large estate in Hertfordshire amongst other projects. A keen and passionate gardener all her life, Philippa lives in rural Cambridgeshire where her ever increasing organically maintained vegetable and fruit garden provide a year round harvest of interesting crops, despite being on heavy clay.