Sun instead of lights? - Newbie

JoeP · February 25, 2011

This is my second year gardening and I'd like to try starting some tomatoes from seed. I've read through a few related threads about lights. I'd like to know if anyone just uses low tunnels (PVC hoops with plastic cover -unheated) instead of shop lights inside the house?

I ask because my only south facing window in my house is not safe from my 2 small children (3 & 2 yo). I could use lights on my workbench in my unheated, un-insulated garage (connected to house) but I worry about nighttime temperatures getting too low. I suppose lights inside would be much more convenient than carting a flat of seedlings in at night and out in the morning.

I spoke with two growers at farmer's markets that sell tomato seedlings (thousands of them) from unheated greenhouses. Could my low tunnel work the same?

I am guessing this question has already been asked so feel free to point me to an earlier thread.

Thanks in advance,

Joe in cool, wet, western Washington
25 or so planned tomato varieties

JoeP · February 25, 2011

I forgot to ask in first post:

In a recent post "Warning: Do not do this to your seedlings", Raybo has a picture of leggy seedlings (cukes I think) that have fallen over after an afternoon in the sun. I am sure there is a reason why an afternoon of sunlight would have a detrimental affect on 3 week old seedlings? (I'll go reread thread to see why)

Since my PNW climate is cloudy and cool in spring, would what passes for sunlight here do the same for seedlings for me? Also, my cloche/low tunnel cover is plastic that is not completely clear. More translucent than transparent, especially after a season of use. I assume this would have a filter effect on any direct sunlight?

ArcherB · February 25, 2011

I have no South facing windows either. I placed half my plants on a window facing east and other half in a window facing west. You would think that there would be no difference between the two, but that was not the case. Those in the east window became leggy. Those in the west window are fine. I have since moved my east window plants back to my light setup where they are doing better.

The only difference between the two is the west window has light blocking drapes that are white on the back side. The plants are on the window sill, between the drapes and the window. The only thing I can figure is that the white backing reflects more of the light back onto the plants. It may also be that it more likely to be cloudy in the morning, meaning those facing the rising sun in the east spend more time with cloud filtered light. My windows also have some kind of high-efficiency tint on them that is supposed to keep the house cooler. All windows have this tint, so that is not responsible for the difference. It just means that they are not exactly in DIRECT sunlight.

As for the leggy seedlings, without reading the post you are talking about, it is my guess that the seedlings were already leggy. One day in the sun will not make a seedling leggy. What may have happened is that the leggy seedlings who had spent all of their time indoors were not at all hardened off. Once they were outside for the first time, they experience wind and direct sun, which can be problematic if the seedlings are not used to that type of treatment. In my experience, a cool wind will do more damage to pampered, unhardened seedlings than direct sunlight. It is important to gradually introduce seedlings to the harsh environment outside. I've had a strong, 60 degree wind decimate a tray of seedlings within a few hours.

les matzek · February 25, 2011

hi joe,
what works for me as soon as they sprout i set them in my mini greenhouse and bring them back in the house (about 4:30 p.m.
this way there are hardened off from day one,they are under a
4 foot 8 tube t5 fixture.
to protect the seedlings cover them with clear plastic bottle or
sheating (vented),ihave used 5 gallon water jugs with the bottoms
cut off this worked well for me before i built my mini greenhouse
good luck.

les

erlyberd · February 25, 2011

The answer to the original post...Sure low-tunnels work great but with no heat source and during cold weather (nights) your limited to day time use only.

I use both, lights and low-tunnels and even a hoophouse. I like to start the plants under lights for the first 30 days and then utilize my low tunnel during the day. I have no heat source so I need to bring plants in at night. When the nights get warm enough I place the low tunnel inside my hoophouse and plant my tomatoes. Last year I was able to plant a full 6 weeks before last spring frost.

Keep in mind that your only gaining around 10 degrees over night time temps using cold frames/low tunnels. Its a lot of work but if your after early harvests then this is what you need to do.

Good luck with your seedlings! You'll never buy starter plants again, I promise!

dice · February 26, 2011

I grow in Western Washington. I do not get tomato volunteers
sprouting in the gardens until mid-May at the earliest. Soil
temperatures are simply not warm enough for them to sprout
earlier. By then my indoor started seedlings are already 8-12
inches tall.

I sprout them under lights in a 70F+ room, then take them
outside into one of these mini-greenhouses once they have
a couple of sets of true leaves:
http://www.amazon.com/Gardman-Rainbo...8707792&sr=1-1

I put a trouble light in the bottom with a 60-75W bulb, plugged
into an inline photoelectric day-night switch, to keep the
temperature inside the mini-greenhouse above freezing at
night. (Be sure to check in the evening to make sure the bulb
did not burn out, the light is not unplugged, the photoelectric
switch is still working, etc.)

The vinyl covers last about 3 years, then you start to need
pieces of tape along the seams, etc.

Tomato seeds need warmth to sprout. Once they are up you
can move them into a colder area to actually grow until you
are past last frost and can transplant to where you want them
in the garden.

This historic document has a description of starting them
outdoors under cover in a hot bed (it uses buried manure
to provide the heat):
http://aggie-horticulture.tamu.edu/p...er_tomato.html

What you describe is more-or-less winter-sowing:
http://www.wintersown.org/wseo1/How_to_Winter_Sow.html

I have not tried that here with tomatoes. (Our weather is
so variable. I will get winter-sown perennials and herbs
sprouting in a stretch of nice weather in late March and
early April that are under severe threat when freezing
nights return before the first week of May. I end up having
to cart flats and containers back into the house at night
to keep freshly sprouted seedlings from freezing until we
get past last frost.)

If you want to try it, Suze mentioned some Agribon fabric
that has protection down to 28F with 85% light transmission:
http://www.johnnyseeds.com/p-5452-ag...r-83-x-50.aspx

JoeP · April 7, 2011

Quote:

Originally Posted by dice

I sprout them under lights in a 70F+ room, then take them
outside into one of these mini-greenhouses once they have
a couple of sets of true leaves:
http://www.amazon.com/Gardman-Rainbo...8707792&sr=1-1

I put a trouble light in the bottom with a 60-75W bulb, plugged
into an inline photoelectric day-night switch, to keep the
temperature inside the mini-greenhouse above freezing at
night. (Be sure to check in the evening to make sure the bulb
did not burn out, the light is not unplugged, the photoelectric
switch is still working, etc.)

So I have most of my seedlings at the true leaf stage and ready to transplant into 4" pots. Now to move to the mini-greenhouse as suggested above.

Does anyone have an opinion on which material is better for the mini-greenhouse material? The link above is for a clear plastic model. There is also a model with thicker material with a green nylon thread in a lattice configuration laminated between the clear plastic (polyethelene maybe). I suppose this diffuses the light but is that what I want? Link below.

http://www.amazon.com/Gardman-R688-W...f=pd_sim_ol_23

Also, since this is a slightly larger model, would a 250W red heatlamp (brooder lamp) be too hot for a night time heat source - plugged into photoelectric day-night switch as suggested above. I have one of these heat lamps as a spare.

I am interested to hear your opinions.

dice · April 7, 2011

I have not used one of those. Did you read the reviews at the
bottom of the Amazon listing?

As for the built-in shade cloth, I have not needed that. When it is
sunny, water evaporates from the pots on the inside and fogs up
the vinyl on the clear ones, so they get diffused light anyway.
When it is not sunny, completely clear plastic is fine. In a climate
with much hotter sunlight in spring, that might be a help.

I expect that the brooder light would be ok. It may fry the vinyl
coating on the wire on the bottom shelf, so you might want to
leave it on one night with no plants in it to find out. Mine sit on
a concrete patio, and I put a couple of bricks under the bottom
shelf and set the trouble light right above them, with the bulb
cage down and the shield up. I would think you would want
something like that to aim the brooder light at, so it would
absorb heat and then radiate it back for a couple of hours
even after the light goes off.

When daytime temperatures are below 50, the plants stay alive
but do not grow much. One can tell by the purple stems and
undersides of leaves that they are suffering from temperature
induced phosphorus deficiency, even in potting mix that has
had a mild dose of fertilizer added (so there is phosphorus in
the growing media available to the roots; the plant is simply
not taking it up below some minimum temperature).

The vinyl covers do not quite reach all the way to the concrete
patio that they are sitting on. I have used newspaper on the
inside around the bottom to cover the gap, a foot or so of
plastic wrapped around the bottom on the outside and held in
place with duct tape, etc. Even when temperatures get below
freezing, it is not very far below freezing in this climate, high
20s F usually at worst at this time of year, so a few small air
leaks are not fatal to the seedlings as long as there is a heat
source inside.

The location where mine sit is protected from the wind, and
the weight of the flats of seedlings in them tend to keep them
in place.

The flimsiness of the covers is not really that big of a problem,
because it is easily replaced with some 6-mil plastic from
a hardware store, the same stuff that people use to cover
pvc hoophouses. Once one has the frame and shelves,
one can throw away a cover once it wears out, and simply
drape plastic over the whole thing, weighed down around
the edges with bricks, cinder blocks, short lengths of 4x4
lumber, or whatever to keep it in place against the wind.

February 25, 2011	#1
JoeP Tomatovillian™ Join Date: May 2010 Location: Washington Posts: 97	Sun instead of lights? - Newbie This is my second year gardening and I'd like to try starting some tomatoes from seed. I've read through a few related threads about lights. I'd like to know if anyone just uses low tunnels (PVC hoops with plastic cover -unheated) instead of shop lights inside the house? I ask because my only south facing window in my house is not safe from my 2 small children (3 & 2 yo). I could use lights on my workbench in my unheated, un-insulated garage (connected to house) but I worry about nighttime temperatures getting too low. I suppose lights inside would be much more convenient than carting a flat of seedlings in at night and out in the morning. I spoke with two growers at farmer's markets that sell tomato seedlings (thousands of them) from unheated greenhouses. Could my low tunnel work the same? I am guessing this question has already been asked so feel free to point me to an earlier thread. Thanks in advance, Joe in cool, wet, western Washington 25 or so planned tomato varieties Last edited by JoeP; February 25, 2011 at 01:48 AM. Reason: spelling

February 26, 2011	#6
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	I grow in Western Washington. I do not get tomato volunteers sprouting in the gardens until mid-May at the earliest. Soil temperatures are simply not warm enough for them to sprout earlier. By then my indoor started seedlings are already 8-12 inches tall. I sprout them under lights in a 70F+ room, then take them outside into one of these mini-greenhouses once they have a couple of sets of true leaves: http://www.amazon.com/Gardman-Rainbo...8707792&sr=1-1 I put a trouble light in the bottom with a 60-75W bulb, plugged into an inline photoelectric day-night switch, to keep the temperature inside the mini-greenhouse above freezing at night. (Be sure to check in the evening to make sure the bulb did not burn out, the light is not unplugged, the photoelectric switch is still working, etc.) The vinyl covers last about 3 years, then you start to need pieces of tape along the seams, etc. Tomato seeds need warmth to sprout. Once they are up you can move them into a colder area to actually grow until you are past last frost and can transplant to where you want them in the garden. This historic document has a description of starting them outdoors under cover in a hot bed (it uses buried manure to provide the heat): http://aggie-horticulture.tamu.edu/p...er_tomato.html What you describe is more-or-less winter-sowing: http://www.wintersown.org/wseo1/How_to_Winter_Sow.html I have not tried that here with tomatoes. (Our weather is so variable. I will get winter-sown perennials and herbs sprouting in a stretch of nice weather in late March and early April that are under severe threat when freezing nights return before the first week of May. I end up having to cart flats and containers back into the house at night to keep freshly sprouted seedlings from freezing until we get past last frost.) If you want to try it, Suze mentioned some Agribon fabric that has protection down to 28F with 85% light transmission: http://www.johnnyseeds.com/p-5452-ag...r-83-x-50.aspx __________________ -- alias Last edited by dice; February 26, 2011 at 03:46 AM. Reason: added details

April 7, 2011	#8
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	I have not used one of those. Did you read the reviews at the bottom of the Amazon listing? As for the built-in shade cloth, I have not needed that. When it is sunny, water evaporates from the pots on the inside and fogs up the vinyl on the clear ones, so they get diffused light anyway. When it is not sunny, completely clear plastic is fine. In a climate with much hotter sunlight in spring, that might be a help. I expect that the brooder light would be ok. It may fry the vinyl coating on the wire on the bottom shelf, so you might want to leave it on one night with no plants in it to find out. Mine sit on a concrete patio, and I put a couple of bricks under the bottom shelf and set the trouble light right above them, with the bulb cage down and the shield up. I would think you would want something like that to aim the brooder light at, so it would absorb heat and then radiate it back for a couple of hours even after the light goes off. When daytime temperatures are below 50, the plants stay alive but do not grow much. One can tell by the purple stems and undersides of leaves that they are suffering from temperature induced phosphorus deficiency, even in potting mix that has had a mild dose of fertilizer added (so there is phosphorus in the growing media available to the roots; the plant is simply not taking it up below some minimum temperature). The vinyl covers do not quite reach all the way to the concrete patio that they are sitting on. I have used newspaper on the inside around the bottom to cover the gap, a foot or so of plastic wrapped around the bottom on the outside and held in place with duct tape, etc. Even when temperatures get below freezing, it is not very far below freezing in this climate, high 20s F usually at worst at this time of year, so a few small air leaks are not fatal to the seedlings as long as there is a heat source inside. The location where mine sit is protected from the wind, and the weight of the flats of seedlings in them tend to keep them in place. The flimsiness of the covers is not really that big of a problem, because it is easily replaced with some 6-mil plastic from a hardware store, the same stuff that people use to cover pvc hoophouses. Once one has the frame and shelves, one can throw away a cover once it wears out, and simply drape plastic over the whole thing, weighed down around the edges with bricks, cinder blocks, short lengths of 4x4 lumber, or whatever to keep it in place against the wind. __________________ -- alias

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February 25, 2011	#3
ArcherB Tomatovillian™ Join Date: Feb 2009 Location: Austin TX Posts: 200	I have no South facing windows either. I placed half my plants on a window facing east and other half in a window facing west. You would think that there would be no difference between the two, but that was not the case. Those in the east window became leggy. Those in the west window are fine. I have since moved my east window plants back to my light setup where they are doing better. The only difference between the two is the west window has light blocking drapes that are white on the back side. The plants are on the window sill, between the drapes and the window. The only thing I can figure is that the white backing reflects more of the light back onto the plants. It may also be that it more likely to be cloudy in the morning, meaning those facing the rising sun in the east spend more time with cloud filtered light. My windows also have some kind of high-efficiency tint on them that is supposed to keep the house cooler. All windows have this tint, so that is not responsible for the difference. It just means that they are not exactly in DIRECT sunlight. As for the leggy seedlings, without reading the post you are talking about, it is my guess that the seedlings were already leggy. One day in the sun will not make a seedling leggy. What may have happened is that the leggy seedlings who had spent all of their time indoors were not at all hardened off. Once they were outside for the first time, they experience wind and direct sun, which can be problematic if the seedlings are not used to that type of treatment. In my experience, a cool wind will do more damage to pampered, unhardened seedlings than direct sunlight. It is important to gradually introduce seedlings to the harsh environment outside. I've had a strong, 60 degree wind decimate a tray of seedlings within a few hours.

February 25, 2011	#4
les matzek Tomatovillian™ Join Date: Jul 2010 Location: Landers, CA Posts: 191	hi joe, what works for me as soon as they sprout i set them in my mini greenhouse and bring them back in the house (about 4:30 p.m. this way there are hardened off from day one,they are under a 4 foot 8 tube t5 fixture. to protect the seedlings cover them with clear plastic bottle or sheating (vented),ihave used 5 gallon water jugs with the bottoms cut off this worked well for me before i built my mini greenhouse good luck. les

February 25, 2011	#5
erlyberd Tomatovillian™ Join Date: Jan 2011 Location: CT Zone 5 Posts: 186	The answer to the original post...Sure low-tunnels work great but with no heat source and during cold weather (nights) your limited to day time use only. I use both, lights and low-tunnels and even a hoophouse. I like to start the plants under lights for the first 30 days and then utilize my low tunnel during the day. I have no heat source so I need to bring plants in at night. When the nights get warm enough I place the low tunnel inside my hoophouse and plant my tomatoes. Last year I was able to plant a full 6 weeks before last spring frost. Keep in mind that your only gaining around 10 degrees over night time temps using cold frames/low tunnels. Its a lot of work but if your after early harvests then this is what you need to do. Good luck with your seedlings! You'll never buy starter plants again, I promise!