Friday, 1 October 2010

The coldframe - preparing for Winter

Most serious gardeners have a coldframe, don't they? Such things are pretty useful for bringing on young plants in the Spring, and for providing some protection from wind and frost during the Winter.

This Summer, I removed the lids (aka "lights") from my coldframe, storing them in the garage out of harm's way (they are made of glass, and therefore a bit vulnerable). This meant that I could use the space occupied by the coldframe without having any plants under its cover, where they would have been far too hot. It was actually a very convenient place to keep my pots of herbs. This is what it looked like in August:

The coldframe full of potted herbs
You can see that I stood the pots in plastic saucers to maximise water-retention.

Just recently I removed everything from the coldframe, gave it a clean-up, re-fitted the lids, and generally got it ready for its Winter duties.

Pots removed, stray leaves swept-up
Lids re-fitted
When the coldframe was cleaned-up any ready to go I re-filled it with herb plants like thyme, parsley and mint, as well as four pots containing small Lavender plants which I think will welcome a bit of extra protection. A point to note though is that a coldframe (especially a glass one like mine) will not keep the plants very much warmer than the ambient temperature. What it will do is shield them from the wind, and stop frost settling on them, both of which are really important. Polycarbonate coldframes (which are generally dual-skinned -- i.e "double-glazed") are said to keep the temperature marginally higher, but I wouldn't think it would be more than a degree or so. Coldframes made of polycarbonate have their pros and cons: they are less vulnerable to damage (and less dangerous if they do get broken). They are also lighter, but this can be a disadvantage -- stability in windy weather might possibly be an issue. Polycarbonate ones are also usually cheaper -- perhaps simply because they are lighter and therefore shipping costs are lower.

The cleaned-up coldframe re-populated
When using the coldframe in Winter, don't forget to check from time to time whether the plants inside it need a bit of water, because they won't be able to benefit from any rainfall. I think it's also good to open the lids for a few hours if you get a nice sunny day, in order to let some fresh air in. This minimises the risk of fungal growths taking over in the humid conditions.

You can see that there wasn't enough space for everything to go inside the coldframe, and the Chive plants drew the short straw. I didn't want the coldframe to be over-crowded, because that also inhibits air-circulation. The Chive plants will survive OK and will die back anyway even if they are protected, and next Spring I will re-pot them just like I always do.


  1. Enjoying your blog. Starting to think you never sleep!

  2. Yes, well... It is a fact that as you get older you do sleep less! But in present circumstances I'm so enthused with blogging that I want to be writing all the time. May not be able to keep up the current rate of posting for ever though.

  3. Hi David; Earlier this year it got down to -12 or so (Centigrade) several times, but -17 once or twice. This is unusual for us in the South of the UK though. Normally it only goes 3 or 4 degrees below. We usually only get snow for a few days a year, not for weeks on end like we did this Spring.


Thank you for taking time to leave me a comment! Please note that Comment Moderation is enabled for older posts.