[JohnB47]

Can you folks educate me about heated seed propagators? I'm thinking of getting one (or more) to germinate onion seeds next Jan/Feb in my unheated garden shed.

I have a number of questions, like:

How do they work, ie are there different ways of heating (bulbs/heating mats of some sort). Are there good types and less good?

How do you use them - leave them on all the time and a thermostat takes care of things, or turn them on at night only?

How much do they cost to run?

How do you manage things if they encourage initial growth but you can't give the plants enough light, without moving them outside where it's cold.

Any views or recommendations welcome.

Thanks.

[kosh42|EFG]

This thread I started a few weeks back may be of interest: http://chat.allotment-garden.org/index.php?topic=84756.0

[JohnB47]

Excellent, thanks. I'll have a look.

[mumofstig]

the windowsill jobby that I've got, (the one in the other thread) raises the temperature of the base by about 10 degrees and I leave it on 24/7. It uses about the same elec as leaving a light on - I would guess.

I only start seeds from the end of Feb - chillis mostly that early, and they can take a long while to germinate. By the time they have, there is enough light for seedlings to be potted on and
placed in windowledges with tin foil behind to reflect all the availablr light back on the seedlings.

Most sowings I leave until the end of march which is quite early enough IMO 

[JohnB47]

the windowsill jobby that I've got, (the one in the other thread) raises the temperature of the base by about 10 degrees and I leave it on 24/7. It uses about the same elec as leaving a light on - I would guess.

I only start seeds from the end of Feb - chillis mostly that early, and they can take a long while to germinate. By the time they have, there is enough light for seedlings to be potted on and
placed in windowledges with tin foil behind to reflect all the availablr light back on the seedlings.

Most sowings I leave until the end of march which is quite early enough IMO 

So I might get as good a crop of onions if I leave sowing seed in a propagator until mid to late March ? That would be good, because by then the temperature might have risen enough to let me harden them off outside. 

I've never tried growing onions from seed, so I don't want to leave it too late on my first attempt.

[Kleftiwallah]

Traditionally you plant your onion seeds for biggies on your way to your Christmas dinner! 

 (get's you out of the 'ouse when the sprogs are running riot) !  Cheers,     Tony

[JohnB47]

Traditionally you plant your onion seeds for biggies on your way to your Christmas dinner! 

 (get's you out of the 'ouse when the sprogs are running riot) !  Cheers,     Tony

Hmmm, that's what I'm worried about. If I germinate them then, I'll have nowhere warm and bright enough to move them to!

[JayG]

Onion seeds have one of the widest ranges of germination temperatures and don't really need a heated propagator (mine germinated in a couple of weeks in Feb in an unheated greenhouse - the problems came later when planted out and then refused to grow, although they got going later.)

You might find the chart in THIS link interesting if you don't like waiting longer than necessary for seeds to germinate (I personally find the parsnip data quite revealing as it shows why they seem to take forever to come up when sown very early in the year.) 

[JohnB47]

Thanks. Maybe I don't need a propagator. Decisions decisions.

[AnneB]

I always use one to get peppers started off.  I also use it to get tomatoes, courgette, squash and other tender seeds off to a good start, but don't leave things in there too long or they get leggy. 
I keep ours in the front porch and it frees up window sills elsewhere for seeds that manage without constant heat in the early stages.
I aim to get 2 greenhouses (1 at home, and a diy job or polytunnel for the allotment) to try and avoid the whole house being overtaken by seed trays in the early part of the year, but still arguing, sorry discussing, with TOH about where precisely to put them and what sort they should be.

[shokkyy]

Last year I sowed loads of onion seed in modules in mid February and stuck them in my cold spare bedroom (radiator on frost setting). I sowed 2 seeds in each module but in fact most of them came up and I had to thin them out. In the first week in March, I started hardening them off outside. So certainly they seemed to be happy with fairly low temps. This year I might stick them in my new polytunnel and see how they get on there. According to Hessayon, onion seed can be sown outside over the month beginning the last week in February.

I sow all kinds of seeds every year and never use a heated propagator. The most I might do is stick a plastic bag over the pot for things like peppers and tomatoes that appreciate a bit more warmth.

[Babstreefern]

Have never ever used a heated propagator for anything.  I start all my seedlings in the conservatory and let the sun have a got (although not all day as its east facing, so only gets the sun in the morning).  Everything comes up, and I've never ever lost anything.  So just use your normal seed trays and get cracking.  I start my onion seedlings every year on 29 December as I'm busy on Christmas day, have a break from doing absolutely nothing on Boxing Day (hubby does all the work ), then we go away for a night on 27/28 December, and then nothing but seeds on the 29 December.  Actually, its my favorite job, as its start up time with Spring just around the corner

[cooperman]

Sow my onion seed on new years day (if poss) into the heated propogator, immediately they are up take out of the propogator and grow on in an unheated light position (i have a light unheated annex/utility room and grow on there until big enough to prick out into modules (60 to a tray) then about early feb transfer either to the unheated greenhouse or the cold frame and grow on in there and then plant out about end of March.... seems ro work for me

[stompy]

I only use my propagator for the greenhouse and tender stuff, Toms/Chillis/Peppers/Melons/Cucumbers/Courgettes/Squashes and Punpkins.

Everything else is sown in cell trays in the unheated minni greenhouse or loft.

I would deffinately get one though as i feel i get quicker/better germination and the seed sheds its outer shell quicker duie to a more vigorouse germination so you don't get scorched leaves which can stunt the plants growth.

I may have a go at onions from seed this year as i have only ever grown from sets before.

[JohnB47]

Thanks for all the info. Very interesting to read the different ways that people do things.