I have recently bought a Sankey electric propagator & I have noticed that
the heat generated is much higher than my other propagators.
In my heated greenhouse which runs at approximately 62F the soil temperature
in the Sankey can rise to nearly 95F.
This compared with my large Parasene propagator of 80F which is about the
same as two other small cheap propagators.
It is noticeable that the seeds germinate quicker in the Sankey but they
also look more leggy that the others.
What is the ideal temperature for a propagator.

SH

"Springtime" wrote in message
...
I have recently bought a Sankey electric propagator & I have noticed that
the heat generated is much higher than my other propagators.
In my heated greenhouse which runs at approximately 62F the soil
temperature
in the Sankey can rise to nearly 95F.
This compared with my large Parasene propagator of 80F which is about the
same as two other small cheap propagators.
It is noticeable that the seeds germinate quicker in the Sankey but they
also look more leggy that the others.


What is the ideal temperature for a propagator.

SH


That would depend on what you're growing, but it appears a soil
temperature range of 65F to 80F is considered adequate for most
purposes. And there are plenty of seeds which would germinate in
an unheated propagator where the ambient temperature was already
62F. And others where even 62F would be too high.

The fact that the ambient temperature is already 62F may account for
the difference in the performance of the different makes. Possibly
Sankey design their propagators to reach an optimum temperature
in an unheated situation, however defined, whereas Parasene don't

If you raise the overheating Sankey off of the bench this may
dissipate some of the heat. Or run it on simple timeswitch.

But all other things being equal, 95F not only seems far too
high but a waste of electricity.


michael adams

....

I have recently bought a Sankey electric propagator & I have noticed that
In my heated greenhouse which runs at approximately 62F the soil
temperature
in the Sankey can rise to nearly 95F.

I bought a Sankey just over a year ago and had exactly the same problem.
Mine held two standard seed trays and was rated at 22 watts - ie 1 unit of
electricity (Kwh) per 45 hours, or 5 pence per day.

I raised the same point on this forum. On reflection, I think it was a
false economy to buy one without a thermostat. There is a heated mat built
into the bottom, which, without a thermostat, constantly consumes 22 watts.
This will raises the temperature, say, about 30 degrees above ambient. If
ambient in your greenhouse is -30F, the pad will raise it to 0F inside the
propagator. If the ambient is 100F, it will raise it to 130F inside. So
the temperature you get depends on the ambient.

I also bought a small propagating thermometer. I found (as you would
expect - on reflection) a big temperature gradient from the bottom of a pot
to the top. The heating mat itself might be running at 120F, an inch above
it the soil might be 100F and another inch above the soil might be only 80F.
You will get a temperature gradient like this in any propagator as the soil
is a poor conductor of heat. I put mine on a sheet of polystyrene, so as
not to lose heat downwards, this just makes it hotter above. Even a small
amount of ventilation will change the temperature. The net result is that
you are not in control of this and most other propagators. And if you are
measuring the temperature on the surface, your plant roots could be 20F
hotter.

Solution. I bought a freestanding thermostat, which cost more that the
propagator - but then as a physicist I like to be in control. Otherwise 1)
reduce the ambient temperature of your greenhouse, or 2) put an inch or two
of sand in the base, with your pots on top. This lifts your plants farther
from the heating element, and 3) open the ventilator.

Hi, Everyone - first post on here, so I'm hoping someone can leap to my rescue!

Just bought a Sankey GroWarm 300 heated propagator from a local Focus which is closing down. The top has a few bits of damage to it, but those are mendable - the one thing I'm struggling with is the fact that the promised Instruction Leaflet isn't in the box. Lovely husband (head gardener, chief pruner) says that it just needs plugging in, but I don't want to kill all my precious seeds before they've even called me Mother. As it were.

Could anyone out there point me in the right direction, please, even if it's just to tell me what not to do!!

Thank you! - hope you all had a lovely Christmas!