I have had some seeds germinate very quickly and others in the same environment go slowly or not at all. I've seen others post similar comments so, I know I'm not alone in this.
I have a heat mat set up in the house to provide a fairly steady heat of about 83F to 87F. Most times the seeds sprout in less than a week. I have several times had some go for over 3 weeks to as much as 4 with no germination. I then carried them out to the greenhouse and left them on the bench where they cool to maybe 60F at night then if it's sunny 85F to 90F in the daytime. After just a few days of this heat cool cycle, they have sprouted with very high germ rates.
I realize this is not even close to a scientific test but it sure seems to be more than coincidence. Might be worth a try for some of the stubborn seeds.
I have a heat mat set up in the house to provide a fairly steady heat of about 83F to 87F. Most times the seeds sprout in less than a week. I have several times had some go for over 3 weeks to as much as 4 with no germination. I then carried them out to the greenhouse and left them on the bench where they cool to maybe 60F at night then if it's sunny 85F to 90F in the daytime. After just a few days of this heat cool cycle, they have sprouted with very high germ rates.
I realize this is not even close to a scientific test but it sure seems to be more than coincidence. Might be worth a try for some of the stubborn seeds.