[jambop]

Just sowed my tomatoes yesterday and put them in the small cold frame against the south wall. As soon as the sun hits it the temp goes up and normally stays about mid to late 20's C this is maintained for the day and then I cover the frame up at night to keep the cold off it so it is a not bad way to get them going. I was however thinking to myself maybe I should get an electric one? But then thought wait a minute when seed germinate naturally the get more or less exactly what I am giving them except the night time protection why would I want to move to a constant temp which is nothing like what seeds get when nature is in charge. What are the thoughts on that? I understand why we as gardeners want quick germination BUT is it actually what is best for the seeds and future plants?

[Yorkie]

I'm not familiar with the growing conditions in SW France, but one thing about electric propagators is that they will maintain a much more even overnight temperature, leading probably to more reliable or quicker germination.  But if you've not had problems with this in the past, why change?

[jambop]

Yes I agree Yorkie. The point I came to was that naturally germinating seeds are subjected to a lot of temperature changes whereas an electric one just maintains a constant temp which sort of got me thinking what is actually best for the plants natural or artificial germination conditions? I know we like to get our fruit early but in a standard summer down here anyway you would get, and I have grown them, loads of tomatoes that were seeds from the previous summers fallen fruit. Two problems with that though 1. you don't know what tomato you are going to get and 2. They are later maturing ... but if I just put a cloche over the area I grew toms the year before I would probably get tomatoes at just the same time as I do sowing them in a cold frame?

[oldgrunge]

Good point jambop, some seeds germinate better undergoing temperature changes, parsley for instance.

[victoria park]

I don't think the extra heat from electricity is a problem. Far more important is the treatment of the seedling once it has germinated. I take nearly all seeds off the heat when germinated.
I've always assumed the high temperature required by some seeds like chillies to germinate is nature's way of ensuring the winter really is over and no chance of dodgy early weather for the new born. No point springing to life only to be cut down within a week.
I am quite interested in the genetic time stamp of plants though, and believe they have a pre determined time to do their thing, regardless of the conditions and how well they are growing. A bit like us really.

[stompy]

As i see it an electric heated propagator is to germinate seeds out of time or early to give us a longer growing season.
I'm sowing my tomato, chilli and pepper seeds this week in my electric prop as even in my greenhouse which gets to 25c to 30c durin the day and drops to around 5c over night i wouldn't get good germination if any for a good few weeks yet.
I thought a seed of these types needed a temprature above 10c all the time and better still upto 15c to get a possitive germination where the seedling breaks free of the seed casing.

Once through though they need to be off the heat and into as light a place as possible as i'm sure you all know.

Andy

[mumofstig]

...I'm sowing my tomato, chilli and pepper seeds .......Once through though they need to be off the heat

It's the low light levels that have to be avoided as much as possible, hence moving them out of covered propagators to somewhere brighter. It's not necessary for them to be off the heat though, as long as they are getting enough light, they are heat loving plants.

Other vegetables don't really need heated propagators to germinate well, anyway.

[jambop]

I don't know if there has been any study done, I am certain the will have been, on the subject but it would be interesting to know if there is an difference in yield or growth characteristics of plants grown by natural germination methods as opposed to artificial. I am sure there must have been and the results favour the getting it as quickly as possible situation... it seems to be the method that is driving agriculture in general. I for my part have decided to stick to my natural albeit cold frame enhanced method which seems to get me plants ready when required to put in the ground    I tend to take the line that what is the point of raising plants if you cannot give them the correct growing conditions post germination in terms of warmth and light.

[New shoot]

You can cut a slice of tomato and stick it in the soil once it warms up and get seedlings, so an electric propagator isn't needed for them.

You can cope without for most veg tbh - DD famously has never had one and swears by polythene bags and seed trays on the windowsill.

I think the commercial uses of them is more driven by the need to have a consistent crop that can all be harvested at the same time.  They also want to get maximum yield and plan crops for specific weeks to hit orders.  Home gardeners see it as a boon that things mature at different times so stretching the harvest.  If your method gives you the plants you want, as you are ready to plant them out, jobs a good 'un 

[jambop]

Agreed newshoot! The problem with a lot of the do things fast system is that the people who actually formulated it had plants bred specially to take advantage of the conditions they can provide the plants . It is all about cost at the end of the day, a home gardener can do exactl the same as a commercial grower BUT has to spend a fortune to be able to do so for no gain at all... also most of the varieties grown by commercial grower are tasteless for them it is all about tonnage/numbers of product . Home gardeners are lucky in that they can decide that the taste is more important than the yield.

[victoria park]

I find a propagator invaluable for tomatoes, peppers, chillies, sweet corn and the most fussy of plants, cucumbers.

I can extend my cold greenhouse harvest season by at least a month, and take away the worry for 3 weeks or more of whether the seed is faulty or not, especially with crops that have a short window. My early sweet corn can also mature before the badgers start marauding at the end of August, eating everything before them. I've succeeded for many years getting sweet corn at the end of july. I couldn't do that without some electric heat for the seeds.

I've also found that some other seeds don't like hanging around too long if the weather is poor. I don't have a heated greenhouse, central heating or a conservatory, but maybe if I did, I guess I wouldn't need a propagator, as the whole house would be one