Greenhouse hotbed

[tootles]

Has anyone experience of hotbeds in a greenhouse?
I know we are still some way off, but I was thinking of building a hotbed (2mx1mx1m) in the greenhouse for Feb. My greenhouse isn't heated and I was thinking that this would start things off much earlier. Apart from the pong (how bad??) is there anything else I should consider? My plan was to leave the manure in place for the summer greenhouse crops and then chuck it on the beds in the autumn.

[Snadger]

I think the main problem is condensation at a time of the year when fungal problems are rife. You would need to adequately ventilate and this will let a lot of the heat out. Also controlling the heat will be a problem.
One idea the Victorians had was to put the fresh manure on the outside of the greenhouse wall which in turn warmed up the inside. No problems with ventilation on this system either. The wall acts like a heat sink.

You would need a continueos supply of fresh manure probably utilising a south facing wall to keep the heat going though!

Another way is to embed a piping system within the manure to heat up water on a gravity fed system which circulates around a piped heating system.

You could even use a household radiator linked into it!

It will be interesting to find out how you get on with whatever system you adopt and any problems encountered.

Go for it!

PS Just had a thought.............. if you filled an old household radiator about 6 foot long say, scrounged from a skip with water and used this as the Southernmost wall in your greenhouse you could have an external muck heap heating the greenhouse from the outside!
Failing this four radiators joined together (2 long and two short) filled with water with the inside filled with manure would give you an internal heat sink.

Getting carried away now (not by men in white coats, I hasten to add) so I'd better leave it at that!