Hardening off?

RomanX · April 2, 2017

Somehow, somewhere I got the information that the outside temperature must be at least 65 before tomato seedlings can be set outside temporarily.

Every day, I wait for the outside temperature reaches 65 before setting my seedlings out. But between shadows cast by the house and the position of the sun AND this 65 degree requirement. . . the available time is limited!

Is there indeed a minimum outside temperature for tomato seedlings?? ( Not for transplanting into the garden)

I harden off early, as I set my seedlings out daily (all day if possible) for about 3 weeks before transplanting them outside (May 1st).

Labradors2 · April 2, 2017

I put my winter-grown compact tomato pots out any time the temperature is above 60F in NC. The trick for me is remembering to bring them back inside when the sun goes down and the temps start to plummet. The plants do well and produce lots of fruit

Linda

Old School · April 2, 2017

I'm trying what Gary Pilarchik (on youtube) recommends which is to set them out a bit early on as long as the temps are in the 40's at least. I'm trying to get them used to the sun (and wind) a bit before bringing them back in to the comfort and safety of the grow light. My first time trying growing from seed using t5 grow light setup so I am no expert. Just telling you what I've learned and am learning. I am gambling on his experience but have been watching his videos for several years now. Barring any trauma to the plants, I will continue doing this. I just set one tray outside yesterday (peppers) for half an hour and the temp was 48 degrees. It was also an overcast day here in PA. I saw no ill effects. Hope this helps.

dmforcier · April 2, 2017

I don't think 65°F air temp is necessary. The plants like the soil warm, but set the pots in the sun and watch that soil warm right up!

Old School, you're doing just fine. I recommend a fan on the plants indoors, too. The more wind the better (said the guy who didn't live in a submarine).

zeroma · April 3, 2017

I harden off when my seedling are about 3 weeks old, 30 minutes the first day, in a shady location, and gradually move to a brighter, sunnier location for longer times for the next 2 or 3 weeks until our last frost date rolls around.

The fan is also being used indoors 10-30 minutes 2 or 3 times a day. I've been rubbing my hand over them a few times a day before starting to use the fan. I have just 41 seedlings going, so one flat and some 'extras' so it is easy enough to do with so few.

Z

April 2, 2017	#1
RomanX Tomatovillian™ Join Date: Jan 2015 Location: North Carolina Posts: 119	Hardening off? Somehow, somewhere I got the information that the outside temperature must be at least 65 before tomato seedlings can be set outside temporarily. Every day, I wait for the outside temperature reaches 65 before setting my seedlings out. But between shadows cast by the house and the position of the sun AND this 65 degree requirement. . . the available time is limited! Is there indeed a minimum outside temperature for tomato seedlings?? ( Not for transplanting into the garden) I harden off early, as I set my seedlings out daily (all day if possible) for about 3 weeks before transplanting them outside (May 1st).

April 2, 2017	#4
dmforcier Tomatovillian™ Join Date: Apr 2016 Location: Dallas, TX Posts: 3,825	I don't think 65°F air temp is necessary. The plants like the soil warm, but set the pots in the sun and watch that soil warm right up! Old School, you're doing just fine. I recommend a fan on the plants indoors, too. The more wind the better (said the guy who didn't live in a submarine). __________________ Stupidity got us into this mess. Why can't it get us out? - Will Rogers

April 2, 2017	#2
Labradors2 Tomatovillian™ Join Date: Jul 2013 Location: Ontario Posts: 3,896	I put my winter-grown compact tomato pots out any time the temperature is above 60F in NC. The trick for me is remembering to bring them back inside when the sun goes down and the temps start to plummet. The plants do well and produce lots of fruit Linda

April 2, 2017	#3
Old School Tomatovillian™ Join Date: Jul 2014 Location: Central PA, Zone 6 Posts: 93	I'm trying what Gary Pilarchik (on youtube) recommends which is to set them out a bit early on as long as the temps are in the 40's at least. I'm trying to get them used to the sun (and wind) a bit before bringing them back in to the comfort and safety of the grow light. My first time trying growing from seed using t5 grow light setup so I am no expert. Just telling you what I've learned and am learning. I am gambling on his experience but have been watching his videos for several years now. Barring any trauma to the plants, I will continue doing this. I just set one tray outside yesterday (peppers) for half an hour and the temp was 48 degrees. It was also an overcast day here in PA. I saw no ill effects. Hope this helps.

April 3, 2017	#5
zeroma Tomatovillian™ Join Date: May 2012 Location: SW Ohio Posts: 637	I harden off when my seedling are about 3 weeks old, 30 minutes the first day, in a shady location, and gradually move to a brighter, sunnier location for longer times for the next 2 or 3 weeks until our last frost date rolls around. The fan is also being used indoors 10-30 minutes 2 or 3 times a day. I've been rubbing my hand over them a few times a day before starting to use the fan. I have just 41 seedlings going, so one flat and some 'extras' so it is easy enough to do with so few. Z