Topic: Do veg seeds need heat?

[caroline7758]

I'm sure this has been covered before, but couldn't find it in search. I'm not talking about tender veg like toms, peppers etc. I was just wondering as I sowed some more seeds in my cold greenhouse today, whether there are any veg that really need or benefit from additional heat to get them going, or is it just that they will get going quicker with heat? Do you pamper any of yours?

[aj]

Some do, some don't.....

http://organicgarden.org.uk/gardening/vegetables/germination-temperatures

[galina]

Some do, some don't.....

http://organicgarden.org.uk/gardening/vegetables/germination-temperatures

Very useful list.  Thank you AJ.

Just one thing I want to add is bottom heat.  Peppers germinate much better if they have gentle bottom heat.  And lettuce does not germinate well above 25C at all.

The optimum temperature list serves as a reminder how many vegetables we germinate/grow here under less than perfect conditions, especially if we sow too early into open ground.

[Robert_Brenchley]

I germinate peppers on top of the water heater. Obviously standard northern European veg don't need heat, but there may still be times when you want to get them started. I've got a few brassicas on the windowsill beside me.

[small]

That's a fascinating link, thankyou - but I'm really surprised that radish are best at such a high temp. I've always found radish germinate less well if sown in the hottest weather, there are obviously other factors at work.

[kt.]

Just saved it in my favourites.  Thanks.

[pumkinlover]

Thanks I've book marked it too
Shame my soil warming cable is 35 years old an calibrated in farenheit! ;D
Thanks for asking q. Caroline- and timely this is first year I've tried using heat for everything- usually just the toms etc.

[BoardStupid]

Thanks I've book marked it too
Shame my soil warming cable is 35 years old an calibrated in farenheit! ;D
Thanks for asking q. Caroline- and timely this is first year I've tried using heat for everything- usually just the toms etc.

http://www.albireo.ch/temperatureconverter/    ;D

[Digeroo]

Like Galina I am surprised with some of the figures.  Carrots germinated very well on a cold north windowsill within a few days.  I understood that temperatures into the 20s were not sure a good idea apart from anything they dry out.  So I think that saying that the optimum is 27 is odd.  Since the original source of information is from USA I wonder whether they are using varieties which are happier with higher temperatures.

http://www.carrotmuseum.co.uk/cultivation.html

According to this site carrots have a reduced germination above 70 F or 21.1
C so hardly an optimum of 27.

[pumkinlover]

Thanks I've book marked it too
Shame my soil warming cable is 35 years old an calibrated in farenheit! ;D
Thanks for asking q. Caroline- and timely this is first year I've tried using heat for everything- usually just the toms etc.

http://www.albireo.ch/temperatureconverter/    ;D

Cheers Boardstupid

I've book marked that too!!! ;D

[chriscross1966]

I think Digeroo hit the nail on the head.... drying out becomes an issue.... I thought my aubergines (ok, tender) were succumbing to damping off.... turns out the compost had dehydrated in the propagator.... I find most things appreciate a little extra warmth to get them going (with the right amount of water) but there's not a lot of point in giving them my more powerful propgagtors, i just use my 8W ones...

[lincsyokel2]

but there's not a lot of point in giving them my more powerful propgagtors, i just use my 8W ones...

yes, you cross the line between bottom heating and pre-cooking if your not careful   8)

[davyw1]

I dint see how the compost you put your seeds in drys out or is allowed to dry out. You put your seeds into compost that has been moistened by water which is at least room temperature cover the seed and place a sheet of glass, perspex or clear polythene kept taught over the top the condensation from the glass etc keeps the compost moist.

As most veg seed germinate better in the dark cover the tray so no light gets in.

A guide to how much compost to cover your seeds is three time the size of the seed.

As for heat make a frame with shelves that will allow the heat to rise through them ans cover it with the thick black polythene and you will need nothing more than a small paraffin lamp

Davy

[Robert_Brenchley]

The danger of that is that it creates a perfect environment for fungi. If I've got seeds anywhere warm I'd rather leave them uncovered, and keep an eye on the pots in case they dry out.

[GodfreyRob]

I avoid damping off by:

Filling seed tray/pot to about 1/2 inch below top (lower for bigger seeds) with compost.
Water well and allow excess water to drain away.
Place seeds on top of compost.
Cover to required depth with dry compost.

I have been doing this for several years and it reduces damping off to almost nothing - and I generally get reliable/uniform germination.

[Robert_Brenchley]

That sounds like a good idea.

[caroline7758]

I find covering with vermiculite also stops damping off.

[Digeroo]

I think tap water is good to prevent damping off.  I used water from a butt last year and within hours there was wipe out.  I also bought a cheapo mini seed growing kit from 99p shop and added some extra seeds, the one on normal compost are fine but all the ones in the kit keeled over, so I think good fresh compost is important as well.

[chriscross1966]

I use Cheshunt compound to avoidf damping off and never have a problem (which was why I surprised when my aubergines started keeling over.... my fault really.... next time I want to put 60 seeds out in a tray I'll use a 15-cell and sow in each corner rather than using a 60-cell insert.... there's a lot more compost per seed even though they're sharing 4 to a cell cos the cell is so much taller and there isn't the boundary through the middle of it...

They dry out in my propagators cos I use vented propagator lids on the heated ones..... as soon as the seeds are up the vents get opened to keep the humidity down..... Normally works fine adn I've got a lot of plants again this year, even the home-saevd and two-year-old-commercial seed is coming up fine.....

Another big sowing session this weekend and I need to get all my coldframes up and running outside.... until the GH is finished I'll have to shuttle about 20 trays in and out every evening, possibly more.... though I've got 48 trays worth of staging in the kitchen at the moment