Heated propagator

I have another question for all you heated propagator veterans

Mine's been plugged in for a couple of hours now, and is now home to loads of tiny pots which in turn are home to a load of seeds.

I'm not convinced its doing anything. There are no lights or anything to indicate any activity, and when I put my finger in, it doesn't feel warm at all. Is that right? How do you know if they're working? Do I leave it plugged in permanently or switch it off when I go out and at bed time?

 

All mine stay on 24/7. Propogators tends to be a gentle bottom heat and it's not always easy to feel if they are working or not.

Put a thermometor inside it to check, or do as I have done in the past, put hand in freezer then in propogator on the base. You should then notice the diffenece and the warmth.

Steve...

 

Clueless as Steve said props can be left on 24 hours. If it is a low powered one with no thermostat control it will raise the temperature of the seed trays by about 5°c. So it is a very low bottom heat source. use a thermometer take the ambient room temp and then lie it on your prop for about 30 minutes , you should see a difference .
When you do get it going the important temp is the actual soil temperature, I have a probe type alcohol thermometer for this. The soil temp can usually get to 25-26° , if I put a bit of bubble wrap under the seed tray the temp is around 22° , and if the seed tray is in the room 18-20°. So you can achieve 3 temperature areas. Now if all this faffing about makes a gods bit of difference who knows :D

 

I bottom mine with a layer of sand. Not sure if it helps but it seems to manitain moisture very well and the odd seed / plant has propagated in the sand.
22W left on 24/7. At the moment its so cold in the conservatory its just protecting some overwintering tenders that will be out soon as its time for some seeds.

 

I guess it must be working. I can't feel any warmth, but the lid has misted up so it must be doing ok I guess.

 

If its misting all is OK

 

I have to leave my hand (I use back of my hand) on mine for a while - 30 seconds to a minute - before I can feel the heat. Its not like touching something that is "hot" so-to-speak.

 

If the heat is so slight that its imperceptible, do they actually make any significant difference to germination rates?

 

Dunno about things that are "harder to germinate" - maybe they need a more sophisticated propagator, but my simple no-thermostat low-wattage windowsill propagators definitely make a difference to germination of Vegetable seeds. Prior to that I put them in pans (stubby-pots), in a plastic bag, on the windowsill (house central heating is pretty consistent 24/7 as I work from home). The propagator got me slightly faster germination, but much more consistent - which made pricking out easier.

 

Clueless - yes I think even a small temperature rise will make a difference. My propagator raises the temperature about 5C above the ambient. It could take 6 or more weeks for outside temperature to rise that much - so that gives you a 6 week start. But if the propagator is inside the house when its still freezing outside, the start can be even more.

I have already germinated Canna seeds this year and the seedlings are now about 3 inches high. I could never have done that without extra heat.

Last year Kristen germinated some Canna seeds early with extra light - they also flowered, went to seed and died whilst it was still frosty outside.

 

That was a MAD but fun project!

01-Oct Sowed seeds
08-Oct Germinated, now growing under lights
27-Nov as per picture
13-Dec Started to flower
18-Jan Set seed !!



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