seeds How hot is too hot for seed germination?

MAFWIZ

MAFWIZ

As some of you may know, I've been having a hell of a time germinating seeds. I've had literally 1 seedling pop up out of 16 in jiffy pellets, and gotten one tail out of another 12 or so using the paper towel method, which was planted a few days ago but has yet to poke his head out. (Hopefully hes still alive in there.)

I know that most people suggest a stable 80-85 for germination. Unfortunately, I cant justify the expenditure for a heat mat & thermostat combo to ensure optimal temps. Thus, my jiffy pellets go outside in the day (in the sun or in the shade depending on ambient temps outside) and my ziplocks live ontop of the cable box.

They are nice and toasty, and I thought probably more or less around 85. But I finally got a thermometer yesterday, and it looks like the box has them at 95 degrees today. In the past, theve only been slightly warmer than ambient, maybe 70 degrees. (The weather has gotten nicer in the last week, temps in the mid 80s outside, 66 inside at the moment.)

But, to my question - is 95 too hot?

Thanks,

Mike
 
95F is not too hot but it is at the upper range for having a decent percentage of germination. Capsicum seeds can germinate as low as 70F but will also have a lower germination rate.

If you already have one seed to germinate in the bag, I would put them all in your starter mix.
 
Can't tell with this device where u live. BUT if it's that warm may not need a heat mat? Not sure but try with and without ...may work out.
 
Last year during our heatwave, with the daytime temps well over 100 everyday, I had excellent germination rates outside.
 
Alright guys thanks for the input, Ill check to see if the weathers going to hold then consider putting the next batch outside to see what happens.
 
MAFWIZ said:
As some of you may know, I've been having a hell of a time germinating seeds. I've had literally 1 seedling pop up out of 16 in jiffy pellets, and gotten one tail out of another 12 or so using the paper towel method, which was planted a few days ago but has yet to poke his head out. (Hopefully hes still alive in there.)

I know that most people suggest a stable 80-85 for germination. Unfortunately, I cant justify the expenditure for a heat mat & thermostat combo to ensure optimal temps. Thus, my jiffy pellets go outside in the day (in the sun or in the shade depending on ambient temps outside) and my ziplocks live ontop of the cable box.
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There is a heat mat/dome combo on Amazon.com for only $25, which isn't all that much. You don't need a thermostat, just put the pellets into the mat once the seeds are in them, and periodically check to make sure they are still moist. I had great success with heat mats this year, and the one I got was not expensive at all.
 
Hendrix not sure where you are from but op is from someplace warm... Your advice sounds like a good way to kill them. If its 95 already and op ads more heat they will die.

My suggestion is to put them in the shade and see what the temp is like...
 
His suggestion would be to bring them inside with the heat mat where temperatures can be easier controlled, which isn't a bad idea at all. You can go get a dinky thermometer at walmart for like a dollar and throw it in your prop if you can't afford the thermostat. Just check the temps at the seed level a few hours after you plug it in. IMO the best way to germinate seeds is to have them somewhere that you don't have to worry about them. A dome in the sunlight on a day in the 80's can easily burn your babies once they pop. Seedlings will be finicky to temps like that. You can chose to put them in the shade or bring them inside. Annuums will germinate at lower temperatures than chinense plants, and I've had strains germinate wonderfully at average temps around 65F. Now I use a thermostat and try to keep the seeds somewhere in the mid 80's. If you're putting them outside though, put them somewhere that you get morning sunlight and shade all afternoon. The temps should stay okay that way I would think.
 
Thanks for the input guys, I've come to the conclusion that most of my issues are related to the wildly fluctuating temperatures I've exposed the jiffy pots to, and probably excessive heat the papertowel/ziplock seeds have been dealing with.

And just to clarify - the 95 degrees is the temperature my ziplocks on top of my cable box were facing. Daytime highs havnt hit that yet this year...although we're probably heading that way soon.

Outdoors has been fluctuating from daytime low 60s to mid 80s durring this process, nighttime lows have been as low as 40s, which seems dangerous for seedlings (I havnt left them out at night ever.) Twice I've left the humidity dome in the shade on hot days, spaced out and come back to find it in direct sun and very, very hot on the inside (this killed some tomato sprouts the first time, nothing had popped yet the 2nd time.)

I'll probably just buy a heat mat for the next round, it's pretty steadily mid 60's in the house which with +10-20 degrees over ambient as advertised by the heat mats, should be about perfect. If it gets much hotter I can just turn of the heat mat.

Alternatively, I think I have figured out the sweet spot on the cable box now that I have a thermometer, I'm getting a nice steady 85 now, and if the weather holds, outdoors in the shade should be fine as well.

I'm still working out the kinks, but I suspect the next batch will be significantly more successful than the first batch!
 
That's what it's all about my friend. In my opinion you only truly learn when you have to fix something going wrong. Pretty soon you'll buy a little something here, learn a little something there, and before you know it 3 years have gone by and you have 40 seedlings in your closet under a nice new grow light. Funny how it seems to work that way.

Best of luck in the rest of your season!
 
I left planted seeds in an overheated growbox where temps reached 40 Celcius (104 Fahrenheit) for about 12 hours... Do you think that I killed the seeds? They were capsicum chinese, capsicum baccatum and Chili tepin tuscon.
 
Heatmats are for guys who grow indoors and/or cold places.  If one has never lived in a year round warm climate, it isn't something that one can relate to, and therefore, the advice may not be relevant.  Your growing environment is perfect.
 
Forget the heat mat.  95 degrees is just fine.  However, you'll need to change up your method a little bit.  Start your seeds in solo cups with drainage holes, or else some large (4" - 5") net pots from the hydro store.  Also, start them in partial sun, or under shade cloth.  You won't have to be as careful as indoors, but still be vigilant about not over-watering.  I promise you, they will come up just fine.
 
I start my seeds outside every year.  I used to start seeds indoors, but the only different results that I ever got from that, was a constant bitching from my wife, about when was I "going to move the damn cups outside"... (was accused several times by my city girl wife of being a "redneck")
 
I use 100 degree C boiling water. Pour it onto coco pellet and sow seed immediately. ambient temperature 32C. keep constant humidity. many seeds still germinate within 14 days.    :hot:
 
 
salceson said:
I left planted seeds in an overheated growbox where temps reached 40 Celcius (104 Fahrenheit) for about 12 hours... Do you think that I killed the seeds? They were capsicum chinese, capsicum baccatum and Chili tepin tuscon.
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Sorry, didn't notice that the topic was so old!
 
I don't think you killed the seeds.  I have pulled seeds out of peppers in the dehydrator, and germinated them.  I typically dehydrate peppers around 112 degrees F, so I think you're fine.  Now, that said... If you had them in a saturated jiffy pellet, it could be a problem.  But since we're talking just one day, I'd just move all of your seed starts to someplace shaded, and wait.
 
The hotter the climate, the bigger your seed starting container should be. (in my experience)  I start my seeds in warm weather in a minimum 4" pot.
 
lek said:
I use 100 degree C boiling water. Pour it onto coco pellet and sow seed immediately. ambient temperature 32C. keep constant humidity. many seeds still germinate within 14 days.    :hot:
 
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why are you doing this?
 
salceson said:
 
why are you doing this?
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just experiment with new way of doing thing.
 
100 degree C water makes coco pellet expand immediately
inactivate some virus
soften pepper seed coat
... blah blah blah
 
stettoman said:
Don't let geonerd into this thread. He'll have 'em boiling their seeds in lacquer thinner and Clorox.... :crazy:
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You're supposed to roll them in Panko flake, afterwards.  Everyone knows that.
 
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