Soil Temperature in Containers

[Jono]

Hi all,

I was thinking about early sowings, which is something I've never had much luck with. I've tried covering the earth with fleece etc, but in the end most the later sowings have caught the early ones up.

I've got some large, black plastic containers, and I was wondering if the earth in these would be warmer than the open soil?

I might cover the containers in fleece or glass if I can find some, but was wondering if anyone knew whether the soil would be warmer in the containers?

If so, I might try some carrots and peas.

Thanks,

Jono.

[teakdesk]

It depends.....

In open ground the temperature at the top changes rapidly as the air temperature changes and when exposed to sun. During the day the top soil temperature rises quickly and falls quickly at night.

Below the surface the soil temperature change is less; the deeper you go the less the fluctuations in temperature change. So deeper soil will not get warm quickly but will keep its heat longer.


In a pot the same thing happens except that the sides of the pot also lose heat as well as the surface; this means that a pot will warm quicker than open soil but it will freeze much quicker as well.


If you put a pot in the sun it will warm during the day but you need to fleece and insulate it very well to retain the heat overnight and on dull, cold days.

If you remove the fleece and insulation before the day has warmed up and the sun has come out then you will lose all the heat.

BUT if you do not remove the fleece and insulation on warm days you will not allow any heat INTO the pot.