Saturday turned out to be the second mildest day of the month as the thermometer reached 15.9°C (60.6°F). That said the strong to gales force winds and frequent showers made the temperature rather irrelevant and we decided it wasn't a day for gardening.
As you can see Saturday’s chart is a real mess.
I have been keeping a record of temperatures to check how much “hardening off” young plants have when they move from our greenhouse to cold frame.
From the values I have so far I’m not that convinced that temperature plays a large part in hardening off our plants. Usually there doesn't seem to be more than 1°C variation between outside, cold-frame and greenhouse.
I seem to remember on Gardener’s World on TV the other week that Monty Don mentioned that he kept his cold greenhouse at a minimum temperature of 5°C. You’ll notice that in our greenhouse the overnight temperature was below that value on eight of the nine nights I have records for. Perhaps under those heated greenhouse conditions hardening off plants is more important but I’m still not convinced that temperatures in a cold-frame are much different to those recorded outside as far as low temperatures are concerned.
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Interesting data! I have a plastic covered cold frame in which I sow all seeds from end of Feb onwards. Sometimes I have snow on it with tomatoes and sweetcorn germinating & they survive - yet I am sure the temp inside is not greatly higher than outside. It must be the protection from the wind & rain etc that matters rather than absolute temps.
ReplyDeleteInteresting data! I have a plastic covered cold frame in which I sow all seeds from end of Feb onwards. Sometimes I have snow on it with tomatoes and sweetcorn germinating & they survive - yet I am sure the temp inside is not greatly higher than outside. It must be the protection from the wind & rain etc that matters rather than absolute temps.
ReplyDeleteInteresting data! I have a plastic covered cold frame in which I sow all seeds from end of Feb onwards. Sometimes I have snow on it with tomatoes and sweetcorn germinating & they survive - yet I am sure the temp inside is not greatly higher than outside. It must be the protection from the wind & rain etc that matters rather than absolute temps.
ReplyDeleteSo sorry - new device, doing its own thing sending multiple copies! Can't seem to delete.
ReplyDeleteI think you're probably right about the plants getting protection from wind and rain in a coldframe. It's more exposed down on the plot than in the garden and plants often seem to get a set back. They normally recover though.
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