Tomato Seed Starting Temps - Page 2

loulac · April 21, 2014

Quote:

RayR quite rightly insists : soil temperature is the important factor in germination.

Most visitors here rightly replaced air by soil in the poll. The temperature of the seed seems to be the only element to take into account. As it is only about 1mm (metric) under the surface it may be influenced by air temperature but only partially.

I'm quite impressed by Joseph's equipment. Really first class. Yet I would replace the fan by a heating mat. Any kind of cover (plastic sheet etc) covering the starting setup would keep air temperature at a satisfactory level.

Besides all seeds don't germinate at the same speed, at the same temperature, so giving a general rule seems very difficult...

SteveS · May 2, 2014

This year I germinated my seeds in a reptile incubator.
Temperature & humidity is adjustable in .1 degree & 1% increments.
Soil temp & air temp are identical.
I settled for 85.5 degrees & 92 % humidity.
I have gotten 95-98 % germination of my own saved heirloom tomato seed.
The same settings have worked very well for peppers too.
I thought of playing with it to try to give the peppers a little more heat but never got around to it.

I have been impatiently biding my time to germinate my giants. I want outside conditions to be absolutely great for when I transplant them & also for warmer conditions when the first blossom trusses arrive!
I haven't found the controller for the outside temps!

cythaenopsis · May 4, 2014

I have a friend who is an experienced gardener and he said that he uses a heating mat only to keep the soil temp from dropping below 60F. Otherwise, he lets the natural warmth of the sun at the windows heat things up during the day, until he's ready to transplant outside.

He swears that by keeping the temps very warm to encourage growth, that in all likelihood the plant will be stringy and not as hearty, that temperature swings are what nature delivers and challenges the plants into developing stronger. I tried to debate him on this, citing that it's about mimicking the ideal temperature conditions and getting ahead on production, but he believes otherwise. If you keep your seedlings exposed to light all day/night and temps in the upper 70's to low 80's, do you effectively extend your tomato production capacity by an extra 3~4 weeks?

SharonRossy · May 4, 2014

All I know is I started germination in a warm location and had so so results with some varieties, one of which was KB. After two weeks I barely got one seed. A couple of weeks ago, I decided to resow more KB on my heated bathroom floor, and within three days I had great germination, so after a few days under lights, I transplanted into 4" pots and under lights for 16 hours, and they look like they are going to be fine by the time we can actually plant out in another four weeks.

Worth1 · September 7, 2014

Where on earth did this come from?

I never took the pole and just saw a new post come up that was posted back in May.
Worth

kath · September 7, 2014

Quote:

Originally Posted by Worth1

Where on earth did this come from?

I never took the pole and just saw a new post come up that was posted back in May.
Worth

Every time a vote is registered the thread gets credited with a new post- even though there might not be a numbered post.

Worth1 · September 7, 2014

Quote:

Originally Posted by kath

Every time a vote is registered the thread gets credited with a new post- even though there might not be a numbered post.

I must have voted without making a reply because I cant vote.

Had me baffled.

Worth

KathyDC · October 23, 2014

I start mine in the house, so whatever the thermostat is set at -- usually around 75 in the winter/spring. I do use a heat mat underneath, though.

Darren Abbey · October 24, 2014

Quote:

Originally Posted by SteveS

This year I germinated my seeds in a reptile incubator.
Temperature & humidity is adjustable in .1 degree & 1% increments.
Soil temp & air temp are identical.
I settled for 85.5 degrees & 92 % humidity.

I've been using an old lab incubator. I have it set at 25C/77F, but it doesn't have humidity control, so it ends up with 100% humidity (assumed from all the condensation on the inside of the door).

It works well, but the condensation makes me worry about it rusting. I hadn't thought about a reptile incubator.

JJJessee · January 29, 2015

I sowed most tomato seeds last year in early April, usually 4-12 in a cluster, close under T8 lamps with a dome, sitting on a heat mat at about 80°. I'll bet the temp got a little above that as long as the dome was on. All varieties broke ground in 3-4 days. By six- ten days they were divided and transplanted into 3.5" deep or 2.5" square pots. @33 days I was planting them in ground. About 6-7 dozen plus give-aways.

View Poll Results: What air temp are your tomato seeds started at?
< 67F	10	11.36%
67-72F	24	27.27%
73-80F	26	29.55%
80-86F	24	27.27%
>86F	4	4.55%
Voters: 88. You may not vote on this poll

May 4, 2014	#18
cythaenopsis Tomatovillian™ Join Date: Jul 2013 Location: Hoboken, NJ USA Posts: 347	I have a friend who is an experienced gardener and he said that he uses a heating mat only to keep the soil temp from dropping below 60F. Otherwise, he lets the natural warmth of the sun at the windows heat things up during the day, until he's ready to transplant outside. He swears that by keeping the temps very warm to encourage growth, that in all likelihood the plant will be stringy and not as hearty, that temperature swings are what nature delivers and challenges the plants into developing stronger. I tried to debate him on this, citing that it's about mimicking the ideal temperature conditions and getting ahead on production, but he believes otherwise. If you keep your seedlings exposed to light all day/night and temps in the upper 70's to low 80's, do you effectively extend your tomato production capacity by an extra 3~4 weeks? __________________ I'm GardeningAloft.blogspot.com (container growing apartment dweller)

October 23, 2014	#23
KathyDC Tomatovillian™ Join Date: Aug 2012 Location: Suburban Washington, DC (Zone 7A) Posts: 347	I start mine in the house, so whatever the thermostat is set at -- usually around 75 in the winter/spring. I do use a heat mat underneath, though. Last edited by KathyDC; October 24, 2014 at 06:04 PM.

May 2, 2014	#17
SteveS Tomatovillian™ Join Date: Aug 2008 Location: Bloomington, IN Posts: 123	This year I germinated my seeds in a reptile incubator. Temperature & humidity is adjustable in .1 degree & 1% increments. Soil temp & air temp are identical. I settled for 85.5 degrees & 92 % humidity. I have gotten 95-98 % germination of my own saved heirloom tomato seed. The same settings have worked very well for peppers too. I thought of playing with it to try to give the peppers a little more heat but never got around to it. I have been impatiently biding my time to germinate my giants. I want outside conditions to be absolutely great for when I transplant them & also for warmer conditions when the first blossom trusses arrive! I haven't found the controller for the outside temps!

May 4, 2014	#19
SharonRossy Tomatovillian™ Join Date: Jul 2012 Location: Montreal Posts: 1,140	All I know is I started germination in a warm location and had so so results with some varieties, one of which was KB. After two weeks I barely got one seed. A couple of weeks ago, I decided to resow more KB on my heated bathroom floor, and within three days I had great germination, so after a few days under lights, I transplanted into 4" pots and under lights for 16 hours, and they look like they are going to be fine by the time we can actually plant out in another four weeks.

September 7, 2014	#20
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	Where on earth did this come from? I never took the pole and just saw a new post come up that was posted back in May. Worth

January 29, 2015	#25
JJJessee Tomatovillian™ Join Date: Sep 2012 Location: Abingdon, Va Posts: 184	I sowed most tomato seeds last year in early April, usually 4-12 in a cluster, close under T8 lamps with a dome, sitting on a heat mat at about 80°. I'll bet the temp got a little above that as long as the dome was on. All varieties broke ground in 3-4 days. By six- ten days they were divided and transplanted into 3.5" deep or 2.5" square pots. @33 days I was planting them in ground. About 6-7 dozen plus give-aways.