December is not the most active of months in the garden, but there are still plenty of jobs to get done. There will be some clear and crisp days, perfect for cleaning, pruning, as well as some last-minute sowing. And even on rainy days, you can do some much-needed preparation for next year. Read below for some ideas on what to take care of in December.
What gardening jobs can I do in December in the UK?
Here is a list of jobs you can do this month both indoors (in your home or greenhouse) and outdoors (in your vegetable and ornamental gardens):
- Move houseplants next to a sunny windowsill to make sure they get sufficient light
- Open greenhouse vents on milder days and close them at night. Winter ventilation is essential in keeping humidity at bay
- Prune free-standing apples, pears, currants, and gooseberries. However, you should not prune stone fruit trees until spring or you risk silver leaf disease.
- Prune grape vines by mid-December
- Protect plants and pots from frost damage. Use cloches or fleece on delicate plants like salad leaves or young cabbages
- Remove debris or leaves to tidy up borders
- Check newly planted shrubs, roses, etc. for wind rock (i.e. loosened soil around the base) and take protective measures. See below for tips
- Prune woody ornamental plants (unless frost or snow is forecast) with shears or pruners
- Mulch if the weather is still mild
- Shake off snow from hedges and shrubs
- Prevent water-logging by placing pots on pot feet or bricks
Tip: How to protect plants against the wind:
In winter, plants are susceptible to root rock, wind scorch, etc. To prevent damage, you can:
- Give some plants a light prune
- Move potted plants to a sheltered location, e.g. against a house wall
- Mulch around plants to improve the soil structure and help the roots to “anchor” themselves
- Check the supports of young trees and shrubs and adjust them as needed.
- You can install windbreak netting or willow hurdles to create shelter
- Clean and store empty fabric pots for next season
- Insulate outdoor taps and pipes to prevent freezing
- Cover compost bins or heaps to keep them from becoming soggy
- Turn compost bins
- Stock bird feeders with seeds, mealworms, and fat balls
- Check your stored fruit and vegetables and remove any mouldy ones
- Plan for next year – you can look for inspiration, evaluate the most successful plant varieties from last season, and create a project plan
- Calculate your needs and order seeds, trays, and pots
What to sow in December in the UK?
December can help jump-start your spring crops in a greenhouse, on your windowsill in propagators, or directly outdoors under cover.
- Lettuce or other winter-hardy salad leaves
- Onions in pots indoors, transplanting them outdoors in spring
- Herb seeds like basil, dill, chives, and mint. Grow them indoors in winter and move outdoors in spring.
- Strawberry plants can be started indoors now and planted out after the last frost.
- Broad Bean (under cloches)
- Plant fruit bushes if weather and soil conditions permit. E.g. raspberry canes, gooseberries, and black currants.
- Divide and re-plant rhubarb.
Tip: How to divide rhubarb:
- Dig a trench around the crown with a sharp spade
- Divide the crown into sections – each one should have a portion of the rhizome (thickened root) and at least one growing point, or more if possible. Sections from the outer part work best
- Any old or decayed parts of the crown should be discarded
- Replant the new plants right away. Otherwise, keep them moist by wrapping them in damp rags until you’re ready to plant
- For the new rhubarb plants, build a hill with a hole in the middle, making sure you mix in plenty of well-rotted organic matter. Plant the crown with the growing point at, or just below, the soil surface.
In December, you can harvest some winter vegetables, such as:
- Artichoke (Jerusalem)
- Brussels Sprout
December can be a busy month, with all the preparations for the festive season, but don’t forget your indoor or outdoor garden. By tidying up, protecting your plants from the cold weather, and sowing new seeds, you can be one step ahead in spring.