Getting cold feet about cold treatment

tnkrer · March 31, 2014

Well, its not exactly cold treatment that I am getting cold feet about, but moving the plants in the unheated garage where the low temp has been around 40 and high temp around 49 in last couple of days. The cold treatment thread says that the temperatures should be in 50-55 range. May be I can put couple of candle warmers in that area and bump up the temperature by few degrees.

So what is the consensus on allowable temperatures. Is it OK to pot up the plants and move them to the garage if for next two weeks, the temperatures stay between 40-50 in the garage? The plants will get light from 8 32W 6500K bulbs in two 4x1 fixtures, so they will not suffer from lack of light and they will be watered from bottom.

Or keep them in the house where temperatures will range between 60-70.
The plants have just sprouted true sets of leaves.

Father'sDaughter · March 31, 2014

Not sure about temps, but right after up potting I personally would let my plants get a bit comfortable in their new container and recover from any transplanting shock before suddenly exposing them to much cooler temps. My basement stays in the low 60's these days, so I just leave all the plants down there until I can start moving them outside for hardening off in mid-May.

Doug9345 · April 1, 2014

I think being in the 40's is just too cold for them.

amideutch · April 1, 2014

Quote:

The plants will get light from 8 32W 6500K bulbs in two 4x1 fixtures, so they will not suffer from lack of light and they will be watered from bottom.

I think if you put a thermometer by the seedlings you will find the temperature higher than the ambient temperature in the garage itself. You can also put cardboard or styrofoam around the back and sides and leave the front open. Also get a 1" slab of styrofoam to set the seedling trays on so they don't get cold feet. You can also cover the cardboard/styrofoam used for the back and sides with aluminum foil to reflect the light back at the seedlings.

Ami

Cole_Robbie · April 1, 2014

I would build a little room around them with painter's plastic dropcloths. Just doing that would help hold in the heat from the light and raise the temp that way. It would also make it easy to heat them to whatever temp you want with a small electric space heater. Obviously, keep the plastic from getting too close to the heater or your lights.

amideutch · April 1, 2014

Here is a link that shows what I was talking about.

http://www.tomatoville.com/showthread.php?t=10818

Stvrob · April 1, 2014

I bet they would be just fine at those temps in your garage, as long as they aren't sitting directly on the concrete floor and they have plenty of light, i think it will be warmer than you think for the plant.
Can you set an oscillating fan to blow across them too?

tnkrer · April 1, 2014

ColeRobbie, Ami,
Thanks about the painters plastic/styrofoam idea. I will try to create an enclosure open on one side and measure temperature at the top of soil in my pots tonight with the lights on. They do give off some heat. With all of that, I feel I can push the low temperature to 50. How about insulation board? Would gypsum board be sufficient? I have some at home

Stvrob,
They will not be sitting on the concrete floor. They will be on a wooden shelf. However, the temperature sensor is sitting on that shelf right now. So those temperatures are from where the plants would be

Basement is great temperature wise, however, kids use that room to play anything and everything when they can't go outside, so there is almost a guarantee that the plants would be crushed by flying balls or worse, flying kids!

Cole_Robbie · April 1, 2014

If your enclosure is open on one side, then the R-value of your other walls is not going to matter very much. Heat energy will take the path of least resistance to escape.

Does the garage have insulation in its walls? If not, the foamboard would be good to use to seal out the outside cold coming from an uninsulated exterior wall.

tnkrer · April 1, 2014

I *think* garage walls are insulated. but not sure, never really needed to check.

I could close the enclosure for night, but it feels like that would suffocate the plants. Do plants have claustrophobia? Would they get less oxygen or the gaps will be enough?

Styrofoam board is cheaper .. So i will go with this.

I will build enclosure tonight with some gap up top between the two light fixtures and will measure the temperature inside with the lights on at night.

Cole_Robbie · April 1, 2014

They should be fine. You can open it once a day to exchange the air, and it wouldn't hurt to have some gentle air movement around them as well, for the sake of building strong stems and preventing mildew. At this point in their development, they shouldn't use up the CO2 in a small space in less than a day. If you were growing a large plant in a small space, then it would need to be vented more regularly, but seedlings don't require as frequent air exchange.

taboule · April 1, 2014

This is how i keep them warm

matilda'skid · April 2, 2014

Some Christmas lights not LEDs would give off heat. Don't use big ones they might give off too much heat.

Cole_Robbie · April 2, 2014

Great pictures. I like the quonset hoop of foil insulation. That is smart.

chalstonsc · April 2, 2014

Put your seedlings against whatever garage wall, if any, divides the garage from a heated room in your house as against that wall will be warmest. Also raise your seedlings off the ground as high as you can since the air at the top of the garage will be the warmest. In my garage, on a loft can be 10 degrees plus warmer.

March 31, 2014	#1
tnkrer Tomatovillian™ Join Date: May 2013 Location: MA 6a/b Posts: 352	Getting cold feet about cold treatment Well, its not exactly cold treatment that I am getting cold feet about, but moving the plants in the unheated garage where the low temp has been around 40 and high temp around 49 in last couple of days. The cold treatment thread says that the temperatures should be in 50-55 range. May be I can put couple of candle warmers in that area and bump up the temperature by few degrees. So what is the consensus on allowable temperatures. Is it OK to pot up the plants and move them to the garage if for next two weeks, the temperatures stay between 40-50 in the garage? The plants will get light from 8 32W 6500K bulbs in two 4x1 fixtures, so they will not suffer from lack of light and they will be watered from bottom. Or keep them in the house where temperatures will range between 60-70. The plants have just sprouted true sets of leaves.

April 1, 2014	#6
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	Here is a link that shows what I was talking about. http://www.tomatoville.com/showthread.php?t=10818 __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

April 1, 2014	#8
tnkrer Tomatovillian™ Join Date: May 2013 Location: MA 6a/b Posts: 352	ColeRobbie, Ami, Thanks about the painters plastic/styrofoam idea. I will try to create an enclosure open on one side and measure temperature at the top of soil in my pots tonight with the lights on. They do give off some heat. With all of that, I feel I can push the low temperature to 50. How about insulation board? Would gypsum board be sufficient? I have some at home Stvrob, They will not be sitting on the concrete floor. They will be on a wooden shelf. However, the temperature sensor is sitting on that shelf right now. So those temperatures are from where the plants would be Basement is great temperature wise, however, kids use that room to play anything and everything when they can't go outside, so there is almost a guarantee that the plants would be crushed by flying balls or worse, flying kids! Last edited by tnkrer; April 1, 2014 at 02:00 PM.

March 31, 2014	#2
Father'sDaughter Tomatovillian™ Join Date: Nov 2011 Location: MA/NH Border Posts: 4,919	Not sure about temps, but right after up potting I personally would let my plants get a bit comfortable in their new container and recover from any transplanting shock before suddenly exposing them to much cooler temps. My basement stays in the low 60's these days, so I just leave all the plants down there until I can start moving them outside for hardening off in mid-May.

April 1, 2014	#3
Doug9345 Tomatovillian™ Join Date: Oct 2011 Location: Durhamville,NY Posts: 2,706	I think being in the 40's is just too cold for them.

April 1, 2014	#5
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	I would build a little room around them with painter's plastic dropcloths. Just doing that would help hold in the heat from the light and raise the temp that way. It would also make it easy to heat them to whatever temp you want with a small electric space heater. Obviously, keep the plastic from getting too close to the heater or your lights.

April 1, 2014	#7
Stvrob Tomatovillian™ Join Date: Jan 2013 Location: Jacksonville, FL Posts: 1,413	I bet they would be just fine at those temps in your garage, as long as they aren't sitting directly on the concrete floor and they have plenty of light, i think it will be warmer than you think for the plant. Can you set an oscillating fan to blow across them too?

April 2, 2014	#13
matilda'skid Tomatovillian™ Join Date: Feb 2010 Location: Missouri Posts: 309	Some Christmas lights not LEDs would give off heat. Don't use big ones they might give off too much heat.

April 2, 2014	#15
chalstonsc Tomatovillian™ Join Date: Jan 2007 Location: sc Posts: 339	Put your seedlings against whatever garage wall, if any, divides the garage from a heated room in your house as against that wall will be warmest. Also raise your seedlings off the ground as high as you can since the air at the top of the garage will be the warmest. In my garage, on a loft can be 10 degrees plus warmer.