River
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Joined: Wed Aug 20, 2014 10:18 pm
Location: Mobile

Temperature question

I built a seed starting rack with hanging shoplights. I have it inside my garage which is attached to the house. The hot water heater (gas) is also located there but on the opposite side sandwiched by the dryer and washing machine. I know it won't get as cold as the outside temps, but on days where we have highs of low 50s lows of 30 at night I wonder how cool it can be where it won't hurt the tomatoe plants.

I could bring them inside on very cold nights. When I leave for work which is usually 6:30-7 am
I will have to put them back in the garage under the lights. I don't have anywhere inside that I can set up the rack.

I don't want to run a electric heater while I am gone to work. Is there anything safe, or will it be ok if the temps are in the high 40s for a couple of days. In the area I live we don't usually have to many extreme days that run together. We might have below freezing at night for a week or so.
During the day it will get into the 50s. One other thing we have high humidity even now, unless a front comes thru.

Any suggestions

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ElizabethB
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Joined: Sat Nov 24, 2012 12:53 am
Location: Lafayette, LA

River - Applestar is the Queen Bee when it comes to growing tomatoes indoors.

Give her a PM.

Happy New Year

Elizabeth

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rainbowgardener
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Location: TN/GA 7b

You need to know how cold it gets inside your garage. You can get a min-max thermometer to check that.

Freezing or below would be killer. But any temps below mid 40's could stunt or damage them.

But what you are most worried about is the soil temperature, not the air temperature (as long as we are not talking about freezing). Heat mats are a safe effective way to keep the soil warmer.

Image
https://www.greenhouses-etc.net/ghse-sun ... mat_lg.jpg

You can get them pretty cheap these days and they will keep your soil 10 to maybe as much as 20 degrees above the ambient temperature. I run two of them through the seed starting season. But if you are talking about needing lots of them it would be a big power drain.

River
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Joined: Wed Aug 20, 2014 10:18 pm
Location: Mobile

I thought about the heat mat. Has anyone ever heard of one catching fire

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rainbowgardener
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I've never heard of it. I have heating pads that are made for people. I would prefer to replace them with seedling heat mats like I pictured, but they just won't die. I run them 24/7 from Jan-April and I have done that for a decade....

River
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Posts: 125
Joined: Wed Aug 20, 2014 10:18 pm
Location: Mobile

I went ahead and ordered the mat for the 20x20 along with the thermostat

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Glad to see you had some really great advice. :D
I keep a remote temp sensor in the garage seed starting area ("V8 Nursery") -- I went cheap with this one and it's a wired sensor passed out of the corner of the doorframe (not wireless) with the main display unit on the adjoining laundry room wall.

I grow cool weather seedlings until mid-Feb, then start peppers and tomatoes. Peppers typically need to stay in an indoor growing area, but tomato seedlings get moved out due to space constraints when overnight garage temp is mostly in the mid-40's and up.... But we still get severe temp dips -- worst could get sub-freezing (upper 20's) but I tent the grow lights and shelves with plastic sheeting -- doubled if necessary, and may make use of strings of Christmas lights to raise temp.

Young tomato seedlings will grow slowly but sturdy and stocky in 50-55°F so that's range of the daytime high temp I aim for. I don't use the heating mat after tomato seeds have sprouted, though I do keep pepper seedlings in heated area until true leaves.



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