Kenneth wrote in
:

Howdy,

I am starting some plants in a rather cool garage. I currently have
them on a heat mat to speed germination.

I want to know more about the effects of the heat from below after the
plants have germinated.

Generally, is it useful to leave the heat on? If not, what are some of
the likely disadvantages?

Unless your propagator is right up against a south-facing window,
continuing to heat after germination will probably produce long, leggy
weakly seedlings.

It does depend exactly what you are trying to grow though.

Victoria
--
gardening on a north-facing hill
in South-East Cornwall
--