December Gardening Jobs UK
December Gardening Jobs UK: Winter Planting & Greenhouse Tips
Key Takeaways
- Ventilate your greenhouse on days above 10°C for 2-3 hours to prevent grey mould—damp kills more plants than cold in December.
- Bubble wrap insulation reduces greenhouse heat loss by 40-50% while still allowing 80% light transmission.
- Check glazing clips and clear gutters before winter storms—a missing clip can cost you an entire glass pane.
- Plant bare-root roses, fruit trees, and hedging now—they're 30-50% cheaper than potted plants and establish stronger roots.
- December tulip planting reduces disease risk by 50-60% compared to October planting.
- Maintain 5-7°C minimum in your greenhouse for most overwintering plants (10-13°C for tropicals).
- Drain outdoor taps or fit insulating jackets—frozen pipes cause average repair bills of £200-£500.
- Keep bird feeders clean and full—garden birds lose up to 10% body weight overnight in cold weather.
December might be the darkest month of the year, but your garden doesn't have to hibernate completely. In fact, this is one of the most important months for December gardening jobs that will set you up for success come spring. With an average of just 7.5 hours of daylight and temperatures dropping to between 1°C and 7°C across most of the UK, December is all about protection, maintenance, and strategic planting.
This guide covers everything from keeping your greenhouse productive through the coldest weeks to planting bare-root trees that will thrive for decades. Whether you're battling grey mould in your greenhouse or wondering if you can still get those tulip bulbs in the ground, we've got you covered.
1. The Greenhouse in December: Regulate and Protect
Your greenhouse is your most valuable asset during winter. While outdoor growing slows to a crawl, a well-managed greenhouse can extend your growing season by 4-8 weeks on either side. But December brings specific challenges that need addressing.
Managing the Microclimate
The biggest killer in December greenhouses isn't cold—it's damp. Botrytis (grey mould) thrives when temperatures hover between 4°C and 15°C with humidity above 85%. December's combination of cold nights and occasional mild days creates exactly these conditions.
- Ventilation is your first line of defence. On any day above 10°C, open vents or doors for 2-3 hours during the warmest part of the day. This air exchange reduces humidity by 15-25% and prevents moisture from settling on leaves. Close everything by 3pm to trap warmth before the temperature drops.
- Heating keeps frost at bay. Most tender plants need temperatures above 5°C to survive, while tropical varieties require 10°C minimum. A 2kW electric heater can maintain a 6ft x 8ft greenhouse 5°C warmer than outside temperatures, costing roughly £1.20-£1.80 per night during the coldest weeks.
Browse our full range of greenhouse heaters to find the right solution for your setup. If you're concerned about running costs, our guide on heating your greenhouse without electricity covers paraffin and thermal mass options.
Insulation Essentials
Heat loss through glass runs at approximately 6W per square metre for every 1°C difference between inside and outside. For a typical 8ft x 6ft greenhouse on a -5°C December night, that's over 300W of constant heat escaping.
- Bubble wrap insulation cuts heat loss by 40-50%. The air pockets create a thermal barrier while still allowing 80% of light transmission—critical during December's short days. Install it on the inside of the glass, leaving a 10-20mm air gap for best results.
- Use proper greenhouse clips rather than tape. Tape fails when temperatures fluctuate, and you'll spend spring scraping adhesive residue off your glass. Quality clips hold firm through -10°C frosts and pop off cleanly in April.
Our greenhouse accessories collection includes insulation kits and clips designed specifically for aluminium and wooden frames.
2. Winter-Proofing Your Structures
Most gardening guides mention "checking your greenhouse" without explaining what to actually check. Here's the detailed breakdown that could save you hundreds in repairs.
Storm Preparation
December brings the highest average wind speeds of the year—averaging 12-15mph with gusts exceeding 50mph during storms. Your greenhouse glazing is most vulnerable during these events.
- Check every glazing clip. On aluminium greenhouses, clips can work loose over time. A single missing clip creates a weak point where wind pressure can lift entire panes. Replacement clips cost under £1 each; replacing a 610mm x 610mm toughened glass pane costs £25-£40.
- Inspect rubber seals and weatherstripping. After 8-10 years, rubber degrades and shrinks, creating gaps that whistle in wind and leak heat. Replacement seals are a simple DIY job and cost approximately £15-£25 for a 6ft x 8ft structure.
- Clear gutters of compacted leaves. Blocked gutters cause water to pool, and when that water freezes, ice can crack glass or warp aluminium frames. A 10-minute clearout prevents hundreds of pounds in damage.
The Vitavia Venus 8x6 Greenhouse features toughened safety glass and integrated guttering designed to handle UK weather conditions.
Water Management
Frozen pipes cause an average of £8,000 in home insurance claims each year. Your garden infrastructure is equally vulnerable.
- Drain outdoor taps or fit insulating jackets. Water expands by 9% when it freezes, and standard brass fittings can't withstand this pressure. A £5 insulating jacket prevents a £150 plumber's bill.
- Empty water butts if they're prone to freezing solid. A full 200-litre butt can crack when ice forms from the top down. Alternatively, float a tennis ball or small plastic bottle on the surface—this gives the ice something to compress against rather than the butt walls.
- Check timber treatment on sheds and outbuildings. December's damp conditions accelerate rot in untreated wood. A coat of preservative takes 2 hours to apply and adds 5-7 years to shed life. Browse our potting sheds collection for pressure-treated options that require minimal maintenance.
3. What to Plant in December (UK)
December isn't a month of explosive growth, but it's perfect for planting dormant stock that will establish strong root systems before spring.
Bare-Root Varieties
Bare-root plants are 30-50% cheaper than containerised equivalents and often establish better because roots haven't circled in a pot. December through February is prime planting season.
- Fruit trees are the best December investment. Apple, pear, plum, and cherry trees planted now will produce fruit 2-3 years sooner than spring-planted specimens. Dig a hole twice the width of the root spread, position the graft union 10cm above soil level, and stake firmly.
- Bare-root roses go in during any mild spell when the ground isn't frozen. Soak roots for 2 hours before planting, spread them over a mound of soil in the planting hole, and ensure the bud union sits just below soil level.
- Hedging plants like beech, hawthorn, and hornbeam establish fastest when planted dormant. A 30-metre hedge costs 60-70% less using bare-root whips versus potted plants.
Winter Harvests and Hardwood Cuttings
Your outdoor plot isn't entirely dormant. December is prime harvest time for several crops.
- Parsnips and leeks improve after frost. Cold temperatures convert starches to sugars, so parsnips harvested after December frosts taste noticeably sweeter than autumn-lifted roots.
- Brussels sprouts are at their best from December through February. Pick from the bottom of the stalk upward, taking 2-3 per plant each week.
- Take hardwood cuttings of soft fruit bushes (currants, gooseberries) and ornamental shrubs (dogwood, willow). Cut 20-30cm pencil-thick stems, dip the base in hormone rooting powder, and push two-thirds into prepared ground. By next November, you'll have 90%+ success rate with free plants.
For tips on keeping your greenhouse productive through winter, read our guide on what you can grow in a greenhouse in winter.
4. Frost Protection for Outdoor Plants
UK temperatures drop below -5°C on average 15-20 nights per year, with most occurring between December and February. Preparation now prevents losses later.
Using Cold Frames and Cloches
Cold frames add 4-6°C to ambient temperature and—more importantly—keep plants dry. In December, wet cold kills far more plants than dry cold.
- Move hardy winter salads into protection. Lettuce, rocket, and lamb's lettuce survive light frosts but rot quickly when cold rain sits on their leaves. A cold frame keeps them productive through January.
- Overwinter tender perennials in frames. Plants like fuchsias, pelargoniums, and tender salvias survive if kept dry and frost-free. Cut back top growth by two-thirds, pot up, and place in a cold frame with the lid cracked open on mild days.
Our mini greenhouses and cold frames collection includes compact options perfect for small gardens and patios.
Protecting Potted Plants
Container plants are 10-15°C more exposed than ground-planted equivalents because cold air surrounds the root ball on all sides.
- Raise pots off the ground. Use pot feet, bricks, or wooden slats to create a 2-3cm gap. This prevents waterlogging, improves drainage, and stops the base freezing to paving.
- Group pots together against a south-facing wall. Thermal mass from brickwork radiates warmth overnight, and grouped pots shelter each other. This simple arrangement can keep roots 3-5°C warmer.
- Wrap vulnerable containers in fleece or bubble wrap. Focus on the pot rather than the plant—the root ball is more cold-sensitive than dormant top growth. Two layers of horticultural fleece provides approximately 4°C of protection.
For detailed advice on protecting specific plants, read our overwintering plants guide.
5. Rainy Day Jobs: Tool Maintenance and Planning
December averages 13-15 rainy days across the UK. Rather than losing these to frustration, use them productively in the shed or greenhouse.
Tool Care
Sharp, clean tools make gardening easier and prevent disease spread. December is the perfect month to get everything in order.
- Clean all cutting tools with methylated spirit. This removes sap residue and kills fungal spores that could spread disease next spring. A 5-minute wipe-down now saves hours of pest management later.
- Sharpen secateurs and shears. A quality sharpening stone costs £8-£15 and transforms cutting performance. Sharp blades make clean cuts that heal quickly; blunt blades crush stems and invite infection.
- Oil wooden handles and metal parts. A thin coat of linseed oil on handles prevents cracking, while a spray of WD-40 on blades prevents rust. Store tools hanging up, not lying in drawers where moisture collects.
- Service the lawnmower. Drain old fuel (it degrades over winter and clogs carburettors), clean the underside, and sharpen the blade. Book a professional service if it's been more than 3 years—a £40 service prevents a £400 replacement.
Planning and Organisation
Organised gardeners grow 20-30% more produce because they waste less time searching for things and more time actually gardening.
- Sort your pot collection. Stack by size, recycle cracked containers, and count what you have. Most gardeners overestimate their pot supply and buy duplicates.
- Tidy greenhouse staging. Wipe down shelves with diluted Jeyes Fluid (1:10 ratio) to kill overwintering pests and diseases. Reorganise so the tallest plants go at the back and light-hungry seedlings get prime positions.
- Order seed catalogues. The best varieties sell out by February. Make a list of what you want to grow, calculate sowing dates working backward from your last frost date (typically mid-May for most of the UK), and place orders before mid-January.
A well-organised potting shed transforms winter planning sessions into genuine pleasure rather than frustrating hunts for mislaid labels.
6. Supporting Wildlife Through Winter
Your garden supports hundreds of species through the lean months. A few December actions make a significant difference.
- Birds: Garden birds lose up to 10% of their body weight overnight during cold December nights. Provide high-fat foods (sunflower hearts, fat balls) and break ice on bird baths daily with lukewarm water.
- Hedgehogs: Numbers have fallen 30% in the last decade. Leave log piles in quiet corners for hibernation. Don't disturb compost heaps, as hedgehogs often sleep in the warm centre.
- Seed Heads: Leave some seed heads standing. Goldfinches and siskins rely on teasels, sedums, and sunflower heads for food through winter.
December Gardening Jobs: Quick Reference Checklist
Use this checklist to ensure you've covered all the essentials:
Greenhouse Tasks
- Check heater function and fuel supply
- Install or repair bubble wrap insulation
- Ventilate on mild days (above 10°C)
- Water sparingly—most plants need 80% less water in December
- Monitor for grey mould and remove affected material immediately
Structural Maintenance
- Inspect all glazing clips and replace missing ones
- Clear gutters of leaves and debris
- Check shed felt for tears or lifting
- Drain outdoor taps or fit insulating jackets
- Float a ball in water butts to prevent ice damage
Planting and Harvesting
- Plant bare-root roses, fruit trees, and hedging
- Harvest parsnips, leeks, and Brussels sprouts
- Take hardwood cuttings of soft fruit bushes
- Plant garlic cloves in well-drained soil
Protection
- Wrap vulnerable pots in fleece
- Move tender perennials into cold frames
- Mulch borders with 5-10cm of organic matter
- Raise pots off cold ground
Frequently Asked Questions
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What can I plant in December in the UK?
December is ideal for planting bare-root trees, roses, and hedging because dormant plants suffer minimal transplant shock. You can also plant garlic cloves directly into the ground, sow broad bean seeds under cloches for early spring harvest, and pot up rhubarb crowns for forcing. Avoid planting anything during frozen or waterlogged conditions—wait for a mild dry spell when soil is workable.
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Is it too late to plant tulip bulbs in December?
Not at all—December planting actually reduces tulip fire disease risk by 50-60% compared to October planting. The cold soil prevents premature growth that's vulnerable to late frosts. Plant bulbs 15cm deep (three times the bulb height) in well-drained soil. You'll still see blooms in April and May, though they may appear 1-2 weeks later than autumn-planted bulbs.
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How do I stop my greenhouse getting mouldy in winter?
Grey mould (Botrytis) thrives in cold, damp, stagnant conditions. Prevent it by ventilating for 2-3 hours on any day above 10°C, spacing plants so air circulates freely, removing dead leaves promptly, and watering in the morning rather than evening. Running a small fan for 30 minutes daily also reduces humidity by 10-15%. If mould appears, remove affected material immediately and increase ventilation.
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What temperature should I keep my greenhouse in December?
Most overwintering plants survive if you maintain minimum temperatures of 5-7°C. Tender tropicals need 10-13°C. Running a thermostatically controlled heater set to 5°C costs roughly £15-£25 per month depending on your greenhouse size and insulation. Combining heating with bubble wrap insulation reduces energy costs by 40-50% while maintaining stable temperatures.
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Can I cut my lawn in December?
Yes, if conditions allow. Grass continues growing until temperatures drop below 5°C consistently. On mild December days (above 8°C), give the lawn a light trim on the highest mower setting—70-80mm blade height. This prevents grass flopping over and developing fungal problems. Never cut frozen, waterlogged, or frost-covered grass, and stay off lawns during prolonged cold spells to prevent soil compaction.
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How do I protect outdoor taps from freezing?
Frozen pipes cause average repair bills of £200-£500. Protect outside taps by turning off the interior stop valve that supplies them, opening the tap to drain residual water, and fitting an insulating jacket (available for under £10). For taps that must remain operational, use an electric trace heating cable wrapped around the pipe—these cost approximately £25 and run on a thermostat that activates below 5°C.
Make December Count
A few hours of preparation in December saves weeks of repair work in spring. Your greenhouse can remain productive, your structures stay sound through winter storms, and bare-root plantings establish strong roots while the garden appears to sleep.
The key is working with December rather than against it. Embrace the slower pace, enjoy the satisfaction of organised sheds and sharpened tools, and take pleasure in the wildlife your garden supports through the lean months.
Ready to prepare your greenhouse for winter?
Browse our complete range of greenhouse heaters, insulation kits, and aluminium greenhouses designed to keep your plants thriving through the coldest months.
The Palram Hybrid 6x4 Greenhouse offers excellent insulation with its polycarbonate panels—perfect if you're considering an upgrade before next winter.
Questions about winter greenhouse management?
Call our team on 0800 098 8877 or email sales@greenhousestores.co.uk. We've been helping UK gardeners since 2012 and have delivered to over 50,000 customers nationwide.
