Get your greenhouse winter ready

Before the frost sets in, it’s time to get your greenhouse ready for winter. Give it a proper clear-out, boost your soil, and why not try growing some real winter crops? Not sure if your greenhouse is up to the task? Find out with the checklist at the bottom of this article.

1. Empty it out

Not planning on growing vegetables over the winter? Then it’s best to clear your greenhouse completely. Harvest the last of your crops and let them ripen indoors if needed. Remove all annuals, plant debris, old roots, and weeds. Anything compostable can go straight onto the compost heap. A clean slate helps prevent fungi and insects from hibernating in decaying leaves and stems, giving you a healthy start come spring.

2. Deep clean time

An empty greenhouse is the perfect excuse for a deep clean. Wash the glass with a mix of water and vinegar to remove algae and let in as much winter light as possible. Clear out the gutters and drains to keep rainwater flowing freely, and check rubber seals for any wear or loose edges. Be sure to remove your automatic vent openers too, they’re not frost-proof.

3. Give the soil a boost

Your soil doesn’t need wings, just a splash of water to stay energised. If your greenhouse was well-watered throughout summer, you’ll only need to add a bit of compost or soil improver. If not, salts may have built up near the surface. In that case, remove the top layer of soil and replace it with fresh earth.

While you're at it, check the pH level of your soil:

• Too acidic (pH < 5.5)? Add some lime to balance it out.
• Too alkaline (pH > 7)? Your soil is craving organic matter like compost or leaf mould.

Got chickens? Let them loose in your empty greenhouse. They’ll weed, gobble up larvae, and leave behind natural fertiliser. Turns out your soil could use wings after all.

4. Growing through winter

Plenty of vegetables are perfectly happy in a winter greenhouse. Garlic can be planted from October to December for harvesting in late spring. Kohlrabi, mustard greens, radishes, spinach, winter purslane, and leafy crops like cut-and-come-again lettuce, rocket, baby leaf and lamb’s lettuce, all thrive when sown in January or February for a steady spring harvest.

Just make sure temperatures stay between 5 and 10 °C. During freezing nights, install bubble wrap insulation with our PVC bubble wrap insulation clips, or set up a small electric heater. Use our chimney plate for safe installation.

These tips also apply if you're overwintering Mediterranean plants like olive trees, citrus, or oleander in your greenhouse.

Checklist: is your greenhouse winter-ready?

• Annual plants, roots and weeds removed
• Glass panels cleaned
• Gutters cleared and seals checked
• Automatic window openers stored away
• Soil improver added and pH tested
• Chickens allowed to roam (optional but recommended)
• First winter crops sown
• Bubble wrap insulation or heating installed