Seed germination temps

Hi guys, I'm getting back into it after a 30 yr hiatus. Question on seed germination. I was reading or the infamous " they say " temperatures from seed germination to seedlings and adults if kept uniform will yield less males. Is this true? possibly? or no real tests done? I ask bc I took my own seeds this year and when I germinate them only one maybe 2 out of ten burst quickly and agressively at 75F. They are only a Month after harvesting them. And a batch of unknown seeds a buddy gave me same thing, it took 85F to make them POP real well. I thought it was an age thing but mine are nice and ripe and a month after harvest. Should they pop faster when nice and fresh? or not necessarily so? They are an F2 of Headband Cookies BX1. OR should I try germination at 80-85F? The grow area will be a consistent 70F surrounding and 72-75 in the tent. I wanted to start from scratch to finish at same temps all the way through. Or does that really not matter for the most part? I plucked the largest best looking 10 seeds out of 100. FYI, I put seeds on plate with wet Paper towel then inside plastic bag and in the chicken egg incubator for consistent temps.

Thanks for any insight.
 

conor c

Well-Known Member
Temperature nutrient content and light spectrum all have influence in sex with seedlings meant to be i never really dug into it much but many think it does have influence on sex like cervantes for example
 

MtRainDog

Well-Known Member
Hi guys, I'm getting back into it after a 30 yr hiatus. Question on seed germination. I was reading or the infamous " they say " temperatures from seed germination to seedlings and adults if kept uniform will yield less males. Is this true? possibly? or no real tests done? I ask bc I took my own seeds this year and when I germinate them only one maybe 2 out of ten burst quickly and agressively at 75F. They are only a Month after harvesting them. And a batch of unknown seeds a buddy gave me same thing, it took 85F to make them POP real well. I thought it was an age thing but mine are nice and ripe and a month after harvest. Should they pop faster when nice and fresh? or not necessarily so? They are an F2 of Headband Cookies BX1. OR should I try germination at 80-85F? The grow area will be a consistent 70F surrounding and 72-75 in the tent. I wanted to start from scratch to finish at same temps all the way through. Or does that really not matter for the most part? I plucked the largest best looking 10 seeds out of 100. FYI, I put seeds on plate with wet Paper towel then inside plastic bag and in the chicken egg incubator for consistent temps.

Thanks for any insight.
I think a little heat source helps. I do the paper towel thing, somewhere between damp and wet. Into a ziplock bag and set on the heat mat at 80F. Most pop and have good sized tails by 48 hours. My only tip is don't make the paper towel too wet.
 

MtRainDog

Well-Known Member
Eh, adding a little heat isn't bro science, it's basic chemistry. Heat is a catalyst for chemical reactions. I won't claim that paper towel and heat mat gives you better germ rates, but I will say it's faster than putting them directly in cold dirt. The one advantage for me using the paper towel method is that I can quickly identify and cull the duds.
 

pegboy

Well-Known Member
Eh, adding a little heat isn't bro science, it's basic chemistry. Heat is a catalyst for chemical reactions. I won't claim that paper towel and heat mat gives you better germ rates, but I will say it's faster than putting them directly in cold dirt. The one advantage for me using the paper towel method is that I can quickly identify and cull the duds.
A little warmth absolutely. I was refering to specific temps dictating plant sex. I don't think theres a single scientific study indicating this.
 

pegboy

Well-Known Member
At least explain your point of view.
I wanted to hear from people that have ideas and opinions also.
Add some value to the conversation!
Refer to my comment above. I should have been a bit more specific as to what the "bro science" I was refering to.
 

sfw1960

Well-Known Member
A very famous (now deceased) breeder told me that dropping the light cycle period gradually would produce more female than male plants.
I have not tried it but would be curious to see if it is a "thing" as I've never had to doubt them before.
 

Phytoplankton

Well-Known Member
haha yeah i didn't want to comment on that part... if you want a better female ratio, germinate on a full moon and wear a stork feather in your cap all week and keep a walnut under your pillow.
All good, but if you really want more females, put the seeds under a tinfoil triangle (must be shiny side out) after scuffing them three times with 600 grit sandpaper thats been soaked in H2O2.(LOL)
 

conor c

Well-Known Member
Eh, adding a little heat isn't bro science, it's basic chemistry. Heat is a catalyst for chemical reactions. I won't claim that paper towel and heat mat gives you better germ rates, but I will say it's faster than putting them directly in cold dirt. The one advantage for me using the paper towel method is that I can quickly identify and cull the duds.
Il agree apart for with landrace stuff or old dormant seeds some of those need cold stages and dirt but for all your modern stuff i just use paper towels for it same as you it is pretty much the easiest way in my experience
 

Hobbes

Well-Known Member
.

I use a heating pad, with a temp sensor, with a tray of rooting plugs acting as a heating mass and avoiding hot or cold areas. I set the temp at 80F.

I put the seeds in wet paper towel, that inside a plastic freezer bag, and in 2-3 days I have sprouts.

.
 

Dorian2

Well-Known Member
I use the same method as some others here. Maybe with one exception which is putting the seeds in a shooter glass of water for 16 - 18 hours. Then I dump that into a double folded paper towel, into a slightly opened ziplock bag, and placed on a beach towel on a shelf in the furnace room. The room is typically 20°C (68°F).

This seems to be a reliable method for me, but YMMV.
 
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