As winter is well and truly on its way now, we’ve decided to insulate the greenhouse. This should keep the place warmer, help keep the frost out, and hopefully reduce the fuel bill when the weather is cold enough to dust off our trusty heater. It should also let us grow a few things over the winter that would struggle to survive outside.
Last year I put a small plastic greenhouse inside the big one, and this was great for starting off some early crops. This year I also want to have a go at growing some winter salads and early potatoes in containers, so decided to insulate the entire greenhouse.
Searching online, I found that the best material is bubble wrap. Apparently you can get specialist stuff which is ideal for the job as it’s UV protected. I only found out this little gem of information after I’d already bought a massive roll of packaging bubble wrap. Deciding to give this a go as we already had it, myself and the other half waltzed off down to the greenhouse at the weekend, to tackle the job in hand.
The first thing to do was to have a good old tidy up, so we harvested the last of the tomatoes and removed the plants. The green tomatoes are now between sheets of newspaper in the conservatory to ripen up. Next up we sorted out the pots and temporarily moved the plants on the staging outside, to give ourselves a clear area to work in.
After a fair bit of ‘to me’ ‘to you-ing’ we’d soon lined the inside of the greenhouse with bubble wrap. As ours is wooden, it fixed onto the frame easily with drawing pins (bubbles towards the glass). If yours is aluminium, special plastic fixings are available from most garden centres.
Now the insulation is up, and especially when we’re using our paraffin heater, the greenhouse will naturally produce more condensation. This could potentially be a problem as too much humidity can be a breeding ground for fungal infections. To get around this, we’ll open the door on clear, sunny days to ventilate the place, and keep the pots and plants inside on the dry side.
The last task of the day was to cut off the tops of the now empty grow bags. I planted a crop of winter peas in one a couple of weeks ago, and these are merrily pushing through the soil as we speak. Into the others went some mixed salad leaves, some spring onion seeds and some radish. With any luck we’ll be harvesting salad well into the winter.