Confused - cold frame start vs. grow lights

navajoah · January 26, 2011

Hi everyone,

I have what is probably a simple problem here but to me is confusing. I have been debating whether to place my starts under T5 grown lamps inside or to take the starts and move them into a cold frame (really sort of a DIY mini-greenhouse). I live in Boulder, Colorado so a cold frame/mini GH would have to have 1) auto vents since the sun here in intense and would certainly cook the plants AND 2) some form of supplemental heat for the cold nights (it can still snow here through early May). It seems like the cold frame/mini GH will be much more expensive given the ventilation and heating requirements. Is a cold frame (or DIY mini-GH) worth it just for starting my tomato plants early? Or will the indoor lighting system be simpler and just as effective in giving my little wonders a good jump start (I also have south facing window that gets lots of sunlight to add supplemental light)?

Secondly, I found what looks like a decent T5 system that produces 10,000 lumens at only 108 watts for $69 (two 54 watt 6400k bulbs) - does that sound like enough light output for approximately 20 tomato starts?

Thanks for any and all advice!!

amideutch · January 26, 2011

Normally I start my seeds in Jiffy 7 type pellets and once they emerge I take the cover off and put them under my grow lights. Once they reach 3" in height I transplant them to 4" biodegradable pots and set them in front of my south facing window and grow them their till I'm ready for plant out. Here's some pics of my setup. Ami

shlacm · January 26, 2011

My impression is that; generally the cold frame is used to get the already fairly large plants (6-8 weeks old) into the ground earlier than would be possible w/out one... so, grow lights would be used up to that point... again, my "impression," 'cause I certainly don't know much about any of this stuff from experience!!!

navajoah · January 26, 2011

yeah, I shouldn't be using the term cold frame since I will be moving the plants to a different location and they won't be settling in where the mini-greenhouse will be. what i was thinking is really just a smaller scale greenhouse used to start the plants in pots for weeks 1-6/8 and then transplant them into the ground. so its not really a cold frame but also not large enough to be considered a greenhouse - something in between I suppose. thanks for the replied though! I appreciate it!

shlacm · January 26, 2011

Quote:

Originally Posted by amideutch

Normally I start my seeds in Jiffy 7 type pellets and once they emerge I take the cover off and put them under my grow lights. Once they reach 3" in height I transplant them to 4" biodegradable pots and set them in front of my south facing window and grow them their till I'm ready for plant out. Here's some pics of my setup. Ami

I want to start my seeds SO BAD after looking at your pics!!! What a beautiful sight!!!

erlyberd · January 28, 2011

You need a portable grow tunnel/chamber/cold frame min 25-36" tall mounted on wheels to move in and out of the garage by day then before night! Otherwise your going to have to handle all those plants a thousand times before you plant them in the ground. I know this from experience but can't take over the garage! It sucks , I know.

So figure first week in Feb start seeds, By March your looking a 5-6" seedlings ready to spend the warmer days in the cold frame until they are ready for the open ground inside your hoop house. This will put fruit on the table in May.

You could always stick to smaller determinates or dwarfs and get away with just a low tunnel which is better than nothing.

Delynnr · February 5, 2011

I am pretty close to you, just a bit North. I have used lights for 6 years with good success. Two years ago I upgraded from normal shop lights purchased in Home Depot, to a 4' T5 setup with 8 bulbs. I have a table setup in my basement and hang the lights from the ceiling so that I can adjust the height of the lights as the seedlings grow.

Personally I think this is MUCH easier than messing with a cold frame and moving the plants back and forth. I setup a fan to blow on the seedlings and I use a timer to switch the lights on and off. Last year I started a around 70-80 tomatoes under the lights and a few random plants. They all were still looking great in mid May when it was time to let them go into the world alone

I usually start my seedlings at the beginning of March and by mid-may I have sturdy, fairly compact, extremely healthy looking seedlings that are about 12-16" tall. I think with a couple of T5's you could pull off 20 plants - just keep them close to the lights (within a few inches) and line up the seedings under the lights.

erlyberd · February 6, 2011

Yes, Easier growing with lights than messing with cold frames and shuffling plants in and out at night but picking ripe fruit before the end of May in New England is priceless! Its amazing what two sheets of plastic and a little dedication can do.

dice · February 6, 2011

Old style hotbed-and-coldframe method (near the top of the
document, at "Starting The Tomato Plant"):
http://aggie-horticulture.tamu.edu/p...er_tomato.html

Some of what is in that document is clearly obsolete,
like the kinds of fungicides/pesticides used, and planting
dates would need to be adjusted for one's local climate,
but it is still relevant and useful.

February 6, 2011

i've tried different ways of doing this and my preference is to keep the seedlings indoors, mainly because it's more comfortable for me to tend to the babies in there where it's nice and warm. would be nice to have a greenhouse that is attached to the house.

i use 4 of the 4-ft fluorescent bulb for a total of 160 watts and 7600 lumens per 36 plants. i sow around Mar 15th in jiffy pellets then transplant to 3.5" pots after 1st set of true leaves shows up in 10-14 days. then they can start moving out in 2 weeks. that's a total of about 1 month indoors.

the 108 watt 10000 lumens T5 system sounds dreamy, i'd like to upgrade to that.

--meg

January 26, 2011	#1
navajoah Tomatovillian™ Join Date: Sep 2010 Location: Boulder, CO Posts: 22	Confused - cold frame start vs. grow lights Hi everyone, I have what is probably a simple problem here but to me is confusing. I have been debating whether to place my starts under T5 grown lamps inside or to take the starts and move them into a cold frame (really sort of a DIY mini-greenhouse). I live in Boulder, Colorado so a cold frame/mini GH would have to have 1) auto vents since the sun here in intense and would certainly cook the plants AND 2) some form of supplemental heat for the cold nights (it can still snow here through early May). It seems like the cold frame/mini GH will be much more expensive given the ventilation and heating requirements. Is a cold frame (or DIY mini-GH) worth it just for starting my tomato plants early? Or will the indoor lighting system be simpler and just as effective in giving my little wonders a good jump start (I also have south facing window that gets lots of sunlight to add supplemental light)? Secondly, I found what looks like a decent T5 system that produces 10,000 lumens at only 108 watts for $69 (two 54 watt 6400k bulbs) - does that sound like enough light output for approximately 20 tomato starts? Thanks for any and all advice!! Last edited by navajoah; January 26, 2011 at 12:53 PM.

February 6, 2011	#9
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	Old style hotbed-and-coldframe method (near the top of the document, at "Starting The Tomato Plant"): http://aggie-horticulture.tamu.edu/p...er_tomato.html Some of what is in that document is clearly obsolete, like the kinds of fungicides/pesticides used, and planting dates would need to be adjusted for one's local climate, but it is still relevant and useful. __________________ -- alias

January 26, 2011	#3
shlacm Tomatovillian™ Join Date: Jun 2010 Location: Central VA Posts: 436	My impression is that; generally the cold frame is used to get the already fairly large plants (6-8 weeks old) into the ground earlier than would be possible w/out one... so, grow lights would be used up to that point... again, my "impression," 'cause I certainly don't know much about any of this stuff from experience!!!

January 28, 2011	#6
erlyberd Tomatovillian™ Join Date: Jan 2011 Location: CT Zone 5 Posts: 186	You need a portable grow tunnel/chamber/cold frame min 25-36" tall mounted on wheels to move in and out of the garage by day then before night! Otherwise your going to have to handle all those plants a thousand times before you plant them in the ground. I know this from experience but can't take over the garage! It sucks , I know. So figure first week in Feb start seeds, By March your looking a 5-6" seedlings ready to spend the warmer days in the cold frame until they are ready for the open ground inside your hoop house. This will put fruit on the table in May. You could always stick to smaller determinates or dwarfs and get away with just a low tunnel which is better than nothing.

February 5, 2011	#7
Delynnr Tomatovillian™ Join Date: Oct 2010 Location: Northern Colorado Posts: 5	I am pretty close to you, just a bit North. I have used lights for 6 years with good success. Two years ago I upgraded from normal shop lights purchased in Home Depot, to a 4' T5 setup with 8 bulbs. I have a table setup in my basement and hang the lights from the ceiling so that I can adjust the height of the lights as the seedlings grow. Personally I think this is MUCH easier than messing with a cold frame and moving the plants back and forth. I setup a fan to blow on the seedlings and I use a timer to switch the lights on and off. Last year I started a around 70-80 tomatoes under the lights and a few random plants. They all were still looking great in mid May when it was time to let them go into the world alone I usually start my seedlings at the beginning of March and by mid-may I have sturdy, fairly compact, extremely healthy looking seedlings that are about 12-16" tall. I think with a couple of T5's you could pull off 20 plants - just keep them close to the lights (within a few inches) and line up the seedings under the lights.

February 6, 2011	#10
akeimou Guest Posts: n/a	i've tried different ways of doing this and my preference is to keep the seedlings indoors, mainly because it's more comfortable for me to tend to the babies in there where it's nice and warm. would be nice to have a greenhouse that is attached to the house. i use 4 of the 4-ft fluorescent bulb for a total of 160 watts and 7600 lumens per 36 plants. i sow around Mar 15th in jiffy pellets then transplant to 3.5" pots after 1st set of true leaves shows up in 10-14 days. then they can start moving out in 2 weeks. that's a total of about 1 month indoors. the 108 watt 10000 lumens T5 system sounds dreamy, i'd like to upgrade to that. --meg