STILL LOOKING FOR A THERMOSTATIC CONTROLLED PROPAGATOR!

[Duke Ellington]

Can anyone recommend one that can be used effectively in an unheated greenhouse. I keep my greenhouse frost free but the run of the mill B&Q tray type electric propagators are ineffective and cannot reach a decent temperature in a cold greenhouse. Any suggestions?. I know some of you have made your own propagators with soil warming cables but I would need instructions on how to make one.

duke :)

[Duke Ellington]

[Ellen K]

With the Stewart-type ones, the thermostat just keeps the chamber from overheating, it's the same heating element as the standard kit, no good to you.  I find my standard double ones get pretty warm even in a cold bedroom (10 C), not so much the single ones so that may be the way to go, with a bit of insulation - maybe standing on a piece of polystyrene would be enough.

If you have tried this sort of thing already, I am at a loss, sorry.

[Tee Gee]

Have you considered a hot bed.

I found that for around the same price as a top of the range propagator I was able to build a hot bed that is abot five or six times bigger than standard propagators,

Here is how I made a  thermostatically controlled heated bench for rooting cuttings or germinating seed that require a temperature of between 50°/60°F (10°/15°C)

The 2.1m x 0.75m (7'x 2.6') hot bed I made is; simply a box formed with treated timber and lined with 1" (25mm) thick polystyrene sheets, and filled with river sand.

Materials

100 x 25 mm treated timber edging= 2@ 2.1m long
100 x 25 mm ditto end boards = 2@.75m
100 x 25 mm ditto base boards with 50mm gap between each board = 12 @ .75m

Note; Obviously if your bed is of a differnt size then you will have to re-calculate the materials

25 mm thick polystyrene sheet 2.1m x 0.75m

River sand as required approx 50 kg

40ft soil heating cable

Rodstat

Nails & screws as required.


Method;

Form timber box from treated timber and put in place.

Note the structure including the sand is quite heavy so it needs good bottom support.

My set up is placed on benches at each end.

An alternative could be 100mm or 150 mm concrete blocks the choice is yours.

Line the bottom of the timber box with polystyrene then add approx 25 mm of sand.

Lay out the cable in a spiral fashion on this sand bed.

Drill the edge board at a convenient point and insert the rodstat, ensure that it does not touch the cable.

Top up the box with the remainder of the sand.

Connect the rodstat/cable to the power supply and that is it!

Note; To prevent the wet sand drying out too quickly I cover it with a sheet of polythene.

By doing this I find the condensates that form under it, do not evaporate, this keeps the sand moist at all times,
thus giving me good heat distribution.


There are a few photos of my set up here;

http://www.thegardenersalmanac.co.uk/Data/Greenhouse%20heating/Greenhouse%20Heating.htm

I hope this is of some use to you.

If you require more info get in touch...Tg

[Duke Ellington]

Thanks for your suggestions TG and Ellen. TG I have given your details to my OH while he was watching the football he said he will look at it later The only propagator I can find at the moment is the vitapod which is coming in at £150.  http://www.greenhousesensation.co.uk/propagators/vitopod-heated-propagators.html?gclid=CJb8meze4rwCFc_MtAodYC8A7A
I have no idea if it is good or bad.

Duke

[Jayb]

Vitopod are pricey but I've found mine excellent, had it for several years and I can't fault it - other than I'd love it if they were cheaper!
Here's a previous thread http://www.allotments4all.co.uk/smf/index.php/topic,74850.msg764914.html#msg764914 looks like they can be used in a greenhouse.

[chriscross1966]

I've got one built the same way as TeeGee's it'sa around 6x3 and uses a cheap big cloche/grow frame as a cover, works wonderfully....