I've seen that as well. Peppers are always slow in germinating, and the seedlings grow slowly. But temperature helps a lot. I just planted out all my peppers. They'll be rip roaring in a month or two.

A yellow belle variety I grow will barely germinate on a heat mat and will take many weeks and then slow to grow, this one needs a lot of heat. But all the other peppers come up in a week. Heat makes a big difference.

Yes, it does. The ambient temp under the lights on the germination rack of my light cart is low-mid 80s; I would think it's even warmer in the covered containers. Most stuff comes up relatively quickly at these temps. There are a few exceptions - some things like it cooler, of course, but the annual flowers and vegetables I grow like the heat.

Don & Dan are like twins separated at birth. Glad they are here to help each other out.

Well, yeah. Many warm season plants like it closer to 80 than 70 for sprouting. Many peppers like it in the 75-85 range, so 70 is kind of overnight cool temp for the seeds. Some species or even varieties can like it a bit warmer, pushing to 80-90 and be very happy. Some can be willing to start in even colder around 65, though they aren't as happy about it.

Sometimes it's also a matter of just how long that pepper takes to germinate. I've grown out peppers that has needed to be started 12+ weeks out, ranging down to about 6 weeks out.

Take a look at any university extension article about vegetable seed germination and you'll see that nearly all vegetables germinate best at soil temps of 75 degrees and above, with some germinating best at 95 degrees (okra, corn, and most cucurbits). The optimum temperature for peppers is 80-85 degrees. The cooler the soil the longer it takes to germinate. The older the seed the longer it takes.

Rodney

I don't think vegetables germinate better at higher temperatures. They just generally do it somewhat faster. Cool season plants like cooler germination temperatures, and warm season plants like warmer temperatures. Several, like parsnips and spinach, clearly germinate more slowly at 85F-ish temperatures.

Yeah, cool season plants like cooler sprouting temps. But isn't this thread about pepper seed temps?

Yep, that's why we're talking about higher temperatures benefiting pepper plants, which are not cool season plants.

It would have been very easy to look up the optimal soil germination temperatures for vegetable seeds before making the false statement of "cool season plants like cooler germination temperatures, and warm season plants like warmer temperatures".

Celery, spinach, and parsnips are basically the only few vegetables that germinate better at temperatures lower than 75 degrees. My initial comment saying "nearly all vegetables germinate best at soil temps of 75 degrees and above" is backed up by countless university websites. Below is a link to just one.

Rodney

https://www.aces.edu/blog/topics/lawn-garden/soil-temperature-conditions-for-vegetable-seed-germination/

I do consider 75 and under on the cool side for germination. Like I consider peas, lettuce, some herbs and alliums, some other greens, and many flowers as cool season plants in addition to parsnips, spinach, celery. Because they can start in cooler conditions, or do start to show up in the garden while it's still cool in the spring, or thrive in cooler conditions, like the greens go kaput once it hits high summer. Much of this seed I don't often start indoors, because direct seeding works well and I don't need to waste the indoor nursery space on them. Though I do sometimes use an outdoor cold frame to pop them quicker.

I consider 80 and up on the warm side for germination. I have found that many plants that like a warm season also like to start out their germination at warmer temps. I probably start more warm season seed in general.

Peppers are for sure a warm season. I know there are some varieties bred for cold climes to be able to be willing to sprout at lower temps, grow for a cooler shorter season. But in general they do come from a warm place and most of them prefer warm conditions from the start.

I consider 90 to be hitting the hot point in germination. I have grown out peppers that like it closer to this for germination. Many years ago I went through a few years of testing and trialing interesting peppers. It was fun, but I wasn't vested enough to continue with a range of 12-6 week starting times with two levels of germination heat. Or some of the garden space, lol. Some pepper plants get to be huge.

Sorry, but cool season plants like cooler germination temperatures is pretty well established. And yes, it's clear about that looking at extension websites.

https://extension.oregonstate.edu/gardening/soil-compost/soil-temperature-conditions-vegetable-seed-germination

Pretty clear from the table presented here.

Not worth an argument.

Dan yet again wins the fake argument that he started. What have we learned here? Not sure who would argue for cool pepper germination.

Cool season plants grow better/ more normal at cooler temps, not sure of the germination rates, but there is little reason to speed up the seedlings in 80 F degree temps just to get long weak floppy seedlings. There you can argue against that.

Well at least you teach actual ideas instead of just playing the contradiction game over and over. I'm limited in growing cool weather plants inside, they germinate fine but grow way too soft inside under LEDs. Need to get them some outside exposure but try to protect from burn or freeze.

I discovered this site years ago, and it's still one I consult every year. https://tomclothier.hort.net/page11.html

That's an interesting site calling out seedling emergence as a function of temperature. But I suspect that's when the seedling breaks out of the seed, and not when it actually penetrates the surface of the soil. That is, I suspect this is about emergence from the seed shell, and not emergence from the soil. Germination is actually the former. The planting depth partly determines the latter.

Tomclothier site bookmarked. I like it.

Yeah, I've hit up the Tom Clothier site many times. If you go to the index button at the bottom of that page, it takes you to the index, heh. There are four databases listing germinations for perennials, annuals/biannuals, penstemons, and trees/shrubs. Quite extensive.