seeds GERMINATION CHART

[Valleyman]

I set out to increase the ambient heat  by supplementing with a space heater directed at the propagation level in the grow stand. Possibly to much of a good thing, I left the heater on high and forgot and after 6 hrs I realized and shut it off. Granted I'm using an inferred thermometer that measures surface temps but the soil clocked in at at about 90-93 F. Hopefully I didn't boil the seeds in their moist environment. I'm still playing with added heat but keeping it on low and I'll see what happens. The seeds were only sown a few days ago.
 
If I'm understanding what I'm looking at, the chart is showing the temp range 77-86 was the best and quickest temp range for spouting and the fringe temps of 68 and 95 still allowing for fair germination rates.
 
So, I think I'm okay. I'll keep you posted.
 
That said it got me wondering and I came across this chart that I'm sharing for THP community.
 

 

[Blitz527]

You should be okay, mine got a little warm too when I put them on the heat mat. Had to add another layer of protection to bring the temps to around 80, they maxed out at around 97 and I'm still getting sewslongs, so here's to hoping

 

[Geonerd]

Low 90s will be fine.  I run my germination chamber (an electric roaster!) around 90 with great success.  From experience in Arizona, I agree with your chart in that exceeding 100F quickly starts to become a bad thing.

 

[TrentL]

Anything over 90 will slow down germination quite a bit, but won't stop it completely. Once you get to 105 or so, you'll get fatalities. I've had seeds survive brief (3 or so hour) exposure to 132F when an 8-Bulb T5 got turned on full blast on a tray that had new seedlings just pop, out of 72 cells, 3 new seedlings croaked, and only about 1/5th of the remaining seeds in the dirt ended up sprouting - compared to 90%+ in other trays. That tray had the humidity dome on, warming mat under it, and a blazing rack of 8-bulbs 8" over the mess. (Light was accidentally turned on by a worker one morning, I stumbled on it a few hours later...)
 
90F+ will start slowing down germination but not stop it, 105F+ will start cooking seeds.