It can be pane sailing to keep on top of your greenhouse
Power through the chilly times with these smart yet simple ways to keep your plants cosy
Now the temperatures are dropping and autumn is at its flame-coloured best, prepare yourself for the meaner months ahead. That means getting to grips with your greenhouse.
When it is warmer, the garden greenhouse is your assistant grower – helping your plants to reach their maximum potential.
When the icy winds and harsh snows arrive, it transforms into the protector and defender of your more vulnerable varieties.
All in all, a greenhouse is a brilliant garden investment, but you do need to make sure yours is ready for winter or the plants inside won’t necessarily survive.
A greenhouse will only stay two to three degrees Celsius above the outside air temperature.
That is fine for a mild frost but if the mercury really plunges, then your precious plants could be in some serious trouble.
As a result, many of us end up running a heater in the greenhouse during the winter.
But if you insulate it, you can save money on your electricity bill and still protect your plants.
With good insulation, you can bring the temperature up to five to six degrees above the outside air, which will serve for all but the most extreme circumstances here in the UK.
Before Jack Frost comes around, first thing to do is make sure all your seals are in good order and you have no cracked or broken panes letting draughts in.
Repair any gaps with ordinary sealant from a tube. It will make an immediate difference, believe me.
Before you add any insulation, give everything a good clean to prevent pests or diseases doing some overwintering of their own.
Use Jeyes Fluid or something similar to disinfect your surfaces and compost any dead plants.
If any plants have picked up diseases, you will want to clear them out and get rid of their soil and pots.
If you haven’t already, remove any whitewash or other sunscreens you put up over the summer to stop plants getting frazzled. They need all the light and UV rays they can get at this time of year.
Now break out the bubbly – I’m talking about horticulturalgrade, Uv-stabilised bubblewrap – and place it along walls and the ceiling, using insulating tape to attach it securely.
This stuff is great, with large bubbles to keep warm air inside the greenhouse. The horticultural-grade version should last at least three years.
Another benefit is that it adds an extra protection against draughts. Plus you can use it to divide the greenhouse down the middle if you need to separate plants with different needs.
Next, line the bottom two feet of the glass with thick cardboard. For extra protection, stuff straw down the back of it. This base cladding will help keep the creeping cold fingers off your floor.
Bring in a large tub or water butt, fill it up, and you have a lowgrade, natural heater ready to go.
This absorbs the day’s warmth and then slowly releases it through the night. It would not be enough to warm your hands, but it is enough to help keep the frost at bay.
When the temperature really dips, then fleeces are a superb extra layer.
You can hang them over groups of plants, wrap them individually or do both for some added protection.
But do keep in mind that plants will need some light, too, and the more fleece you wrap round, the more light they are losing.
Moisture control is another important factor. On sunny days, open the door to clear the air and prevent mould.
Most importantly, do your research on the plants you are overwintering.
Some need light more than warmth so you may need to screen off part of your greenhouse for insulation and leave the other part open to full sunlight. Know your plants and you will be fine.
If things get really desperate you can still bring a heater to the rescue. If you do use one, be aware that gas and paraffin heaters may be a little cheaper to run but their need for ventilation will offset the savings.
I would recommend electric heaters, as they don’t need ventilation and are easier to control – but you will have to think about a power source.
Using heating will also affect the humidity, so be sure they don’t dry your plants out.