In article
,
ljp other wrote:

In the raised bed threads, some people indicated they extended their
growing season by a couple of weeks at either end. We bought a house
with an unheated green house last year and I kept track of the
temperature. Generally speaking the lows in the green house were the
same (-5 to -10 C) as the outside temperature. I did have water in
the green house (~40 litres) to act as a heat sink.

The transition from winter to spring here is abrupt and variable.
Days warm up to 15 C but the overnight lows are well below freezing.

Do the people who have success extending the season live in milder
climates with more gradual springs?

Are there better techniques than using water as heat sink?

Thanks

Try running a drop light out there with a 80 to 100 watt light bulb and
closing everything up tight. This keeps mine from freezing for the most
part.

Some composting in there will heat it too.
--
Peace! Om

"Our prime purpose in this life is to help others. And if you can't help them, at least don't hurt them." -- Dalai Lama