What temps are safe for 3 week Tomatoe plants

[gregory]

I am asking outside temps. I have them under lights, but I thought it may help
To make them stronger on a nice day. This weekend Saturday am 41 high 62
Sunday low 49 high 66. Then another cold front.

[jmsieglaff]

If the plants are hardened off (which may not be the case by the sound of it) and you are confident those are as low as the temps would be and it wouldn't be windy you could leave them out. Could you just put them out during the day so you don't worry about the lows? My tomatoes go into the cold frame in mid/late April and routinely experience temps in the 40s, but protection from wind and bright spring sunlight seems to make up for any cool nights they experience.

If they are yet to be outside, I would just give them a few hours of sun a day to start and go up from there.

[AlittleSalt]

Gregory,

I was thinking along the same lines as jmsieglaff. I asked a good friend here at Tomatoville - basically the same question in a PM. They replied, "Get them out in the dappled shade while it's warm. They can take an hour or two of direct sunlight. Our upcoming high temps are going to be in the 70s for at least 4 days.

Even though, I'm a newcomer to growing tomatoes from seed - I sort of relate tomato seedlings to us humans. If it feels warm and not too windy - we go outside and enjoy it, but if it's cold and/or blustery outside - I'd rather stay in the house. Tomato seedlings are babies in that way - so protect them, but let them enjoy a few hours of 60s in the daytime.

I'm sure there are a lot of others who will disagree. Tomatoville is a society that is forever learning.

[Tapout]

Well, at 3 weeks im still under lights. I dont harden off till about the last two weeks before I put them out for good. Putting your plants out to soon just makes for stressed out plants. I get better growth under lights and constant temperature then outside in a green house. My plants basically dwarf the green houses offerings.

[Father'sDaughter]

Originally Posted by Tapout

Well, at 3 weeks im still under lights. I dont harden off till about the last two weeks before I put them out for good. Putting your plants out to soon just makes for stressed out plants. I get better growth under lights and constant temperature then outside in a green house. My plants basically dwarf the green houses offerings.

This is what I do as well. I've heard too many sad tales of seedlings damaged or lost completely by someone playing the in-and-out game while temps were still marginal and they forgot to get them in, weren't watching the weather closely enough, didn't get home in time, etc. etc.

Until I know they can safely stay out, even over night, they live in the basement under lights. For me, I know this is safer--I get distracted easily.

[Blueaussi]

You don't say how old or what size your seedlings are, so it's kinda hard to say if they're ready to start hardening them off.

In my not so humble opinion, you will *not* make them stronger by putting them under sunlight, then bringing them back inside, which is what I think you're asking. When they're large enough to go outside for good, and the weather is right; then, and only then would I start hardening off my seedlings.

[Sun City Linda]

I live in SoCal and I don't have enough light set ups. My seedlings go outside from the day they pop their little hoops up. I do bring everybody in at night until they get older. I don't run the heat overnight so temps in my house are 50s to low 60s. Currently I have some month olds camping out, its been mostly mid forties. My daytime temps are generally 60-70 although it hit 80 yesterday.

[ScottinAtlanta]

On temps: I keep mine at 40-55 degrees for the whole time they are in pots (10 weeks). They grow more slowly, but add more roots. I think someone on this Forum called this the "cold treatment" last year. I find the root balls are bigger, but the foliage is smaller when I keep them in colder temps. I like that.

[kath]

They do have to be hardened off a bit to be exposed to wind and direct sun, but when I've got seedlings under lights I put them outside any time during the day when the temps are above 55 and it's sunny. (Indoors the temps in the basement vary from 60 F to 65 but the lights I use add a little heat.) I just bring them back in and put them under the lights when conditions are less tomato friendly. What I'll do is provide wind protection and filter the light by rigging up something that will hold a piece of summer weight row cover or some kind of shade cloth over them. I'm home all the time and keep an eye on them, of course, so that helps it work for me. There's no substitute for the real sun and even some breeze is great for their development.

[Tapout]

I keep mine under lights at about 77 degrees for 5 weeks. Then for two weeks I take them outside during the day to harden off and bring them in at night. At 7 weeks my plants are ready to be transplanted into the ground. If there are days that is to cold or yucky during the last two weeks I keep them inside under lights.

Over all any way that works best for you is best for you. Everyone's situation is different. Some people use smaller containers then I do some larger, some never transplant and keep them in the same pot they planted them in until its time to go outside into the ground.

The main thing is that "you" are doing it, you are in control of everything. You know what you put onto your plants and you know what you are eating. I feel a sense of pride when giving my tomatoes away knowing that a little bit of me is in those tomatoes. Everyone who got some of my produce loved them said it was the best they ever had. I dont know if they were just saying that to be nice but it sure makes me feel good just to hear it.

[UFXEFU]

I am new to starting from seed, but put my one week plants out for 4 hours in sunny, low to mid 60's, and kinda windy. When should I start feeding them?

[jmsieglaff]

Originally Posted by gregory

I am asking outside temps. I have them under lights, but I thought it may help
To make them stronger on a nice day. This weekend Saturday am 41 high 62
Sunday low 49 high 66. Then another cold front.

What did you do? How did they end up?

[Worth1]

Folks I would like you to notice something very important.
The advice and or opinions given are from drastically different environments.
There are many days here in the south that are great in the winter.
It would be a waste to have your babies inside.
Worth

[tlintx]

Originally Posted by ScottinAtlanta

On temps: I keep mine at 40-55 degrees for the whole time they are in pots (10 weeks). They grow more slowly, but add more roots. I think someone on this Forum called this the "cold treatment" last year. I find the root balls are bigger, but the foliage is smaller when I keep them in colder temps. I like that.

This is incredibly helpful, thank you. I suspected my issues last year were due to either overwatering or cold temperatures, and this pretty much confirms it was overwatering.

[gregory]

Originally Posted by jmsieglaff

What did you do? How did they end up?

After the earlier posts I decided to leave well enough alone.

I will wait for now and hopefully the weather will be warmer towards the end of this month. Then I will begin the hardening process. I won't be able to bring them in and out during the day unless it's the weekend.