Ideal vs. ok vs. bad temps to set transplants

Solanum315 · April 30, 2019

For now I’d just like to focus on the cold end of the spectrum since I’m a New Yorker. In a perfect world, what night time temps would you like to see to set tomatoes? What is acceptable and at what point is it simply a bad idea due to creating dormancy that will set your plants way behind? It seems to be an unusually cool May this year...

Worth1 · April 30, 2019

Soil temperature is what is very important.
About anything under 60 is sort of a gad idea, the plants just wont grow very well.

Shrinkrap · April 30, 2019

I've always read nights no lower than 55. Even though we get 90 plus,May through September, it doesn't get much above 55 at night here near California Central valley. .

PaulF · April 30, 2019

Agreed on soil temp along with air temp of greater than 50F. Patience is a virtue. We have lots of folks in a big hurry to be first to get the plants in the ground...they usually end up replanting.

Solanum315 · April 30, 2019

Never took soil temps but I’ll have to start since we can have night temps in the 50s in July (occasionally). Thanks all, good info...

oakley · April 30, 2019

Yup, soil temp. Google 'NY soil temp' and you can look it up in your area.
Central NY is 48º today at 4 and 8inches deep. It also give moisture saturation.
Try and wait for 60º.
If our 14day forecast is favorable seeing a steady increase, we will be about on target.
Around the 15th I start looking for a couple days that are overcast.
I need a weekend so 11th / 12th. 18th probably better.
I can't get them in all at once so last batch will see soil first two weeks in June.

KarenO · April 30, 2019

Quote:

Originally Posted by Solanum315

For now I’d just like to focus on the cold end of the spectrum since I’m a New Yorker. In a perfect world, what night time temps would you like to see to set tomatoes? What is acceptable and at what point is it simply a bad idea due to creating dormancy that will set your plants way behind? It seems to be an unusually cool May this year...

Are you planting in ground or in pots or raised beds? Makes a big difference.
Ideal not to go below 10 c ,52F at night but as long as there is no frost they won’t die, they just won’t grow. Wind is also a factor, is your area small and sheltered or open and windy,
I’m not sure I’d ever have a tomato if I waited until soil temp is 60 degrees for 24 hours a day.

There are a lot of variables including variety. What is your growing situation?
KarenO

mikemansker · April 30, 2019

I always plant my seeds too early (can't help it) which gives me plants way bigger than they should be too early. If there are a string of days where the night temps are going to be 50's, they usually go in the ground. Inevitably, we will get some 40's and even upper 30's after that. Overall, I've been pretty fortunate in not losing plants.

MadCow333 · April 30, 2019

I put my seedlings and store-bought plants outdoors on a covered porch or out in the yard as soon as night temperatures remain in the 40s. If it goes into the 30s, I bring them inside for the 1-2 days it takes to get through that. I haven't lost any seedlings or plants, so far. I plant mine in containers, but have never noticed any dormancy or retarded growth. I keep them apparently warm enough to not be adversely affected, and they are "hardened" early. This has been pretty true regardless of variety, or determinate vs. indeterminate. I live in PA/OH border area, near where I-80 crosses the state line. I try to get my plants started as early as possible so that they have a good root system and then can take off when the hotter weather hits. eta: If I could be sure that it will not snow and frost in May, I'd try planting tomatoes earlier than the mid-May target that I usually shoot for.

Shrinkrap · April 30, 2019

This is the first year I put mine in (Eartboxes) before May first in quite a few years, and nights have been around 50 since then. But last night we had wind gusts up to maybe 24 mph, enough to have power outages. I hadn't staked them yet, and had to prop up a few this morning.

bbjm · April 30, 2019

Quote:

Originally Posted by oakley

Yup, soil temp. Google 'NY soil temp' and you can look it up in your area.
Central NY is 48º today at 4 and 8inches deep. It also give moisture saturation.
Try and wait for 60º.
If our 14day forecast is favorable seeing a steady increase, we will be about on target.
Around the 15th I start looking for a couple days that are overcast.
I need a weekend so 11th / 12th. 18th probably better.
I can't get them in all at once so last batch will see soil first two weeks in June.

Thank you for the tip. I had no idea these soil temps were so readily available.

Here is a link I found:

http://www.greencastonline.com/tools/soil-temperature

Solanum315 · May 1, 2019

Quote:

Originally Posted by KarenO

Are you planting in ground or in pots or raised beds? Makes a big difference.
Ideal not to go below 10 c ,52F at night but as long as there is no frost they won’t die, they just won’t grow. Wind is also a factor, is your area small and sheltered or open and windy,
I’m not sure I’d ever have a tomato if I waited until soil temp is 60 degrees for 24 hours a day.

There are a lot of variables including variety. What is your growing situation?
KarenO

This year I will probably plant most in the ground with a few in a a slightly raised bed and a few others in planters, so I guess all three. My plants are only 3-5” tall at this point so they should be ok in their paper cups for 2-3 more weeks at least.

AlittleSalt · May 2, 2019

Paul, I agree with you that patience is a virtue. I have seen many gardeners plant out too early and lose their tomato plants.

brownrexx · May 2, 2019

I only check soil temps for planting my peas in late March and it was above 40 so I am sure that it is above 50 by now but I never check.

My tomato seedlings are totally hardened off and living on my covered front porch until plant out time. My nights mostly drop into the low 50's and sometimes upper 40's but I only bring them inside if the temperature at night drops into the 30's like it did last Sunday night. It is warmer and more protected on the porch than it would be out in the garden.

Temperature wise I would plant them outside now but we are expecting 4 days in a row of rain this week and 3 in a row next week so I don't want to subject the seedlings to that much rain and I will keep them in their pots on the porch for now.

bower · May 3, 2019

Nights of 50 F and above are aok for planting out as long as they are hardened off/cold treated, and lots of varieties will set well in those conditions, but you will see the most setting and fruit growth especially for (most) bigger beefs and hearts, when the night temp is 60 F.
We also get nights in the mid to high 40s which is not a problem unless it becomes a pattern. They won't set when nights are down to 45 F, maybe not below 50 F for most. If the days are at least over 60 F they will tolerate the cold nights much better and aren't affected by the occasional dip below optimal. But I have had plants endure 50 F high temperature

with lows in the low 40s for 2-3 days in a row, and it didn't affect their performance in the rest of season. However they are not growing or making any progress in those conditions! 60 F day temp is the minimum for growth, for most if not all varieties.

If night temps go over 70 F, they won't set either, according to what I've read.

April 30, 2019	#1
Solanum315 Tomatovillian™ Join Date: Jun 2012 Location: New York Posts: 244	Ideal vs. ok vs. bad temps to set transplants For now I’d just like to focus on the cold end of the spectrum since I’m a New Yorker. In a perfect world, what night time temps would you like to see to set tomatoes? What is acceptable and at what point is it simply a bad idea due to creating dormancy that will set your plants way behind? It seems to be an unusually cool May this year... __________________ Scott http://worldtomatoes.blogspot.com/

April 30, 2019	#4
PaulF Tomatovillian™ Join Date: Jan 2006 Location: Brownville, Ne Posts: 3,296	Agreed on soil temp along with air temp of greater than 50F. Patience is a virtue. We have lots of folks in a big hurry to be first to get the plants in the ground...they usually end up replanting. __________________ there's two things money can't buy; true love and home grown tomatoes.

April 30, 2019	#5
Solanum315 Tomatovillian™ Join Date: Jun 2012 Location: New York Posts: 244	Never took soil temps but I’ll have to start since we can have night temps in the 50s in July (occasionally). Thanks all, good info... __________________ Scott http://worldtomatoes.blogspot.com/

April 30, 2019	#9
MadCow333 Tomatovillian™ Join Date: Jun 2015 Location: NW PA 6A Posts: 159	I put my seedlings and store-bought plants outdoors on a covered porch or out in the yard as soon as night temperatures remain in the 40s. If it goes into the 30s, I bring them inside for the 1-2 days it takes to get through that. I haven't lost any seedlings or plants, so far. I plant mine in containers, but have never noticed any dormancy or retarded growth. I keep them apparently warm enough to not be adversely affected, and they are "hardened" early. This has been pretty true regardless of variety, or determinate vs. indeterminate. I live in PA/OH border area, near where I-80 crosses the state line. I try to get my plants started as early as possible so that they have a good root system and then can take off when the hotter weather hits. eta: If I could be sure that it will not snow and frost in May, I'd try planting tomatoes earlier than the mid-May target that I usually shoot for. Last edited by MadCow333; April 30, 2019 at 04:34 PM.

April 30, 2019	#10
Shrinkrap Tomatovillian™ Join Date: May 2006 Location: N. California Posts: 701	This is the first year I put mine in (Eartboxes) before May first in quite a few years, and nights have been around 50 since then. But last night we had wind gusts up to maybe 24 mph, enough to have power outages. I hadn't staked them yet, and had to prop up a few this morning. Last edited by Shrinkrap; May 2, 2019 at 12:32 AM.

April 30, 2019	#2
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	Soil temperature is what is very important. About anything under 60 is sort of a gad idea, the plants just wont grow very well.

April 30, 2019	#6
oakley Tomatovillian™ Join Date: Jun 2015 Location: NewYork 5a Posts: 2,303	Yup, soil temp. Google 'NY soil temp' and you can look it up in your area. Central NY is 48º today at 4 and 8inches deep. It also give moisture saturation. Try and wait for 60º. If our 14day forecast is favorable seeing a steady increase, we will be about on target. Around the 15th I start looking for a couple days that are overcast. I need a weekend so 11th / 12th. 18th probably better. I can't get them in all at once so last batch will see soil first two weeks in June.

April 30, 2019	#8
mikemansker Tomatovillian™ Join Date: Feb 2013 Location: Branson MO Posts: 441	I always plant my seeds too early (can't help it) which gives me plants way bigger than they should be too early. If there are a string of days where the night temps are going to be 50's, they usually go in the ground. Inevitably, we will get some 40's and even upper 30's after that. Overall, I've been pretty fortunate in not losing plants.

May 2, 2019	#13
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	Paul, I agree with you that patience is a virtue. I have seen many gardeners plant out too early and lose their tomato plants.

May 2, 2019	#14
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	I only check soil temps for planting my peas in late March and it was above 40 so I am sure that it is above 50 by now but I never check. My tomato seedlings are totally hardened off and living on my covered front porch until plant out time. My nights mostly drop into the low 50's and sometimes upper 40's but I only bring them inside if the temperature at night drops into the 30's like it did last Sunday night. It is warmer and more protected on the porch than it would be out in the garden. Temperature wise I would plant them outside now but we are expecting 4 days in a row of rain this week and 3 in a row next week so I don't want to subject the seedlings to that much rain and I will keep them in their pots on the porch for now.

May 3, 2019	#15
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	Nights of 50 F and above are aok for planting out as long as they are hardened off/cold treated, and lots of varieties will set well in those conditions, but you will see the most setting and fruit growth especially for (most) bigger beefs and hearts, when the night temp is 60 F. We also get nights in the mid to high 40s which is not a problem unless it becomes a pattern. They won't set when nights are down to 45 F, maybe not below 50 F for most. If the days are at least over 60 F they will tolerate the cold nights much better and aren't affected by the occasional dip below optimal. But I have had plants endure 50 F high temperature with lows in the low 40s for 2-3 days in a row, and it didn't affect their performance in the rest of season. However they are not growing or making any progress in those conditions! 60 F day temp is the minimum for growth, for most if not all varieties. If night temps go over 70 F, they won't set either, according to what I've read.