[jazzbyrd]

I have two basic heated propagators. I usually use them in the house to start off seeds such as chilies an tomatoes etc. I have a power supply in my greenhouse so would it be okay to use the propagators. Do you think this type of propagator can generate enough heat  during very cold temperatures out in the green house. I would like to clear the house of trays of seedlings this year.

Jazz

[Kleftiwallah]

If you have the knowhow, try and have a bash at building your own.   Heater cables and thermostats are available at a reasonable price and I'm sure I've seen snaps of home made jobs on here.   I have one, 8' X 2' and I couldn't do without it now.     Cheers,     Tony.

[mumofstig]

Unless you have the expensive type where you can set the temperature, they only warm the bottom by about 8-10C above ambient, so not enough for stuff like peppers and toms in a cold spell  IMO

[jazzbyrd]

Aaaah okay I will continue to clutter the house with my seedlings!

Jazz

[Ivor Backache]

Aaaah okay I will continue to clutter the house with my seedlings!
Jazz

Just like the rest of us.
I did try a 100watt bulb in a sweet tin with the lid fitted. The tin radiated the heat and I left it on overnight. Can't say I had much success though.

[DD.]

100W bulb could well be over the top.

Some large propagators are only rated at 18W.

[yorky]

Why not heat the whole greenhouse just enough to keep it frost free? That way your propagators will be able to maintain a good temperature. If you line the glass with bubble wrap it does'nt work out too expensive and you get better use of your greenhouse.

[Nikkithefoot]

I have tried my heated propagators in a cold greenhouse and it works for me., but being close to the South Coast that will also have an impact on my success

I start the really sensitive plants off in the propagator indoors, then once they are up move the whole lot out to the greenhouse and plug them in. Once too big for the propagator they get moved into a mini greenhouse inside my greenhouse and the seem to do ok.

[sunshineband]

Unless you have the expensive type where you can set the temperature, they only warm the bottom by about 8-10C above ambient, so not enough for stuff like peppers and toms in a cold spell  IMO

She is right I'm afraid.

The other drawback is that they can get very hot during sunny days and need shading to avoid getting scorched