I read that thread before I posted, but it wasn't clear to me whether a sunny window would do as well. I guess lights provide a much longer day. But from other seedlings I have grown, I wasn't sure whether long days made seedlings leggy.
Also If I am starting fresh with lights, are special grow fluorescents better? Are any of the compact fluorescents full spectrum good?
You can start seedlings in a sunny window, but it requires that you be willing to rotate the plants frequently and that you be willing to accept more leggy seedlings. The plants will stretch toward the light, so rotating helps balance the growth. Since they are stretching to the light, the seedlings will tend to be more leggy, too.
With lights, you need to keep them close to the seedlings, so some way to adjust the height (either of the plants or the lights) is needed. From experiences posted here, it doesn't seem that special grow light bulbs are needed for seedlings. If the plants were going to be fully raised under lights, the answer might be different.
The key to answer your question is how many seedlings are you going to plant, and do you have space for a lighting unit, and is the cost of the unit justified for the number of plants you will have. If you are only going to start a few seeds then you can probably make a good sunny window work well enough.
I am not fortunate enough to have a south facing window so I've used all sorts of grow lights. If the weather prevents me from getting the plants out, they become leggy.
Since I've swithched to a cold frame which faces south, my seedlings do much better
dervish2 - Seedlings always do better outside with "real sunlight". I have one south facing window in my home, and although it provides heat, and light, it does NOT provide enough length. In other words, the sun doesn't shine through that window long enough each day. So any vegetable seedlings grown there become "leggy".
My best alternative has been to use cool white florescent tubes in 48" shop lights. I leave the lights turned on for 16 hours each day with the bulbs almost touching the seedlings.
HoneybeeNC wrote:dervish2 - 16 hours in sunlight would be a long time. The light from indoor illumination is not the same as sunlight. It has to do with something called "kelvin"
Sunlight I think is around 6000K - florescent lamps are probably half that much.
Even if you don't know the meaning of these terms (which I don't) you can see that there is an enormous difference between florescent tubes and the sun.
Main thing is that artificial lights are no where near as bright as direct sunlight.
As far as color temperature, various fluorescents range from 2700k to 6500k.
Kelvin is a temperature scale that has Celsius sized degrees, but starts at absolute zero(-273C).
The color temperature has to do with the color that a hot body has when it is glowing. The higher the Kelvin temperature the bluer the color. Fluorescents are actually an approximation, as it actual consists basically of three colors. red, green, and blue.
The tube marked "daylight" are the 6500K lights and they are the bluest, brightest fluorescent that you can get. I have to get some new bulbs and another shop light and they will be the 6500K bulbs. I stole the 4' shop light over my workbench last weekend and set it up in the seed rack I have a bunch of greenhouses residing. Started seeds last Sunday and the cantaloupes are already almost 2" tall. The only thing that's been slow to germinate is the Bradley Tomatoes. They're just starting to peek through...
dervish2 - Sounds like you have a solution in mind. I agree on the 16 hours if only using grow lights.
We have south facing windows and sliding glass doors that get full sunlight in the winter. I've used them in the past to start seeds and had no problems with growing plants or seedlings there. Right now we use that space to winter over outside plants that are not hardy in our area.
I bought the Jiffy 10 plugs with plastic cover on sale and their directions said "don't" put in the sun so I put the tomato seeds in and then onto the North side of the house window sill and forgot to look for 5 days. The plants were all bent up in there but 2" tall so they had germinated fast. I took the lids off and they are all happy now standing up straight and ready for transplanting since 2 in every plug came up! I'd say not into the full sun windows for a few days after. No lights for me. I tried those years ago and they did nothing for me but make the plants taller trying to get to the lights! I only have 42 plants and that's only 2 trays so will sit them on the window sill and the table next to the window.
Windows only let sun in when it's low in the sky, and you may get big temperature swings right near the glass. Too cvold atnuight, and too hot when the sun comes straight in.
However, when my plants get too big for my light table, I will put them near a big window. I try not to put small, tender seedlings there because they may bake.
"Kelvin", "temperature" and "spectrum" all refer to the color of thye light. In my opinionated opinion: "yada yada yada". The difference between "cool" and "warm" or "Grow-Lux" is a minor factor for vegetable seedlings compared to the real issue: brightness, intensity, "lumens" or "watts per square foot". More is better!
(Maybe fussy indoor plants that spend their whole life under artifical light have color preferences, but veggie sedlings are gourmands, not gourmets. They just want MORE LIGHT.)
With old-style flourescent tubes (T12 shop lights, 48" inch tubes in 2-tube fixtures), you can barely get enough intensity for stocky seedlings, so you have to jam those tubes right in the seedlings' faces. Because the light spreads out with distance despite the reflectors, and it was barely bright enough right next to the tubes, closer is better.
I hear that new T8 and T5 tubes are brighter (more intense, more lumens per tube). Maybe they don't need to be as close to the seedlings.
BTW, "Watts" only refers to how much electricty the lights USE. An efficient bulb can create more light with less power. The least effiicent bulb is an old incandescent bulb, and it uses up 100Watts to make as much light as a modern CFL florescent tube can make with around 35 watts! The rest of that eloectiricty is wasted as heat.
So a T8 bulb might use fewer watts than an old T12 tube, but put out more lumens (like saying "puts out more photons"). I THINK the T5 tubes use a little more electricity, but put out LOTS more light. I'm not sure, but they look brighte4r to me in the showroom.
Hey Rick... I'm PRETTY SURE the T8's & T12's are different size tubes and different pin configurations.
A couple of years ago Big Lots had a sale on flourescent fixtures for $5.00 each. Picked up 4 8 foot lights that are T12's, but the 8 footers are a single pin and the one socket is spring-loaded so the bulb will slide in place. The 4 foot bulb has the standard 2 pins.
HoneyNC...The T8 is a newer bulb designation and has a better efficiency rating than the T12. Still using the T12's, I am not sure if they, the 8's, have the different temperature ranges that the 12's do. I STOLE my 4' light from over my workbench last weekend to set up the germinator shelf in the other end of the workshop. When I buy some new lights, they're gonna be the T8's since they are better lights and more efficient.
>> I'm PRETTY SURE the T8's & T12's are different size tubes and different pin configurations.
OK, you're probably right. I was going from memory and not one I was sure of. I still think that I saw some fixture advertised which could take either of two kinds of bulb. Maybe it was T8 or T5.
Maybe my memory is just Swiss cheese.
Every so often I go to a Habitat for Humanity "Restore" and hope to find super cheap 4 foot fixtures of any kind.
If I were very ambitious, and had the time, I would look up exact DIY schematics for T5 fixtures and see if a four-tube ballast would drive or over-drive three tubes. Then just pay for the reflectors and ballasts and make some extra-bright three-tube fixtures. (But four closely-spaced tubes might be safer.)
BTW: do most people fit TWO trays under 48" shop lights "the long way" so the trays cover an 11"x42" area?
Or do they put FOUR trays under one light to cover a 21"x44" area? I'm just dreaming -
Maybe a four-tube T5 fixture with bulbs spaced to cover a 21" width instead of 11", would be bright enough to pack four trays on one shelf 21"x44". I think that consolidating the areas to be "double wide" would give more uniform brigthness, less light loss, and more intensity near the middle.
Rick - the T8's I purchased have a smaller diameter than the T12's.
I only have one tray this year, but if I had two, I would place them long ways under the 4ft shop light. Even so, I see the seedlings lean towards the middle of the tray.
Quoting:Maybe a four-tube T5 fixture with bulbs spaced to cover a 21" width instead of 11", would be bright enough to pack four trays on one shelf 21"x44". I think that consolidating the areas to be "double wide" would give more uniform brigthness, less light loss, and more intensity near the middle.
I too, thought of doing this, or something similar next year. (There's always a "next year!") My shelves are certainly wide/long enough for such a set-up.
Rick - My thought about the paneling or thin plywood is that they might not take the weight you wish to place on them without bending. Don't know about the drywall.
When I moved here in October 2006, I had a five-year plan to get the North end of the backyard free of grass and build up the soil until it had good tilth. I'm pleased to say, I accomplished that goal.
I now have a new goal - to do the same with the South end of the backyard where hubby is removing running bamboo.
Muy understandinmg is that T5 tubes NEED a T5 fixture: as ifr the ballast has to match.
Please don't take my word for it, but MAYBE you can plug T8 tubes into a T12 fixture - I seem to recaall that but don't trust my memory.
T8's will fit the sockets on T12 fixtures and vice versa. They will most likely will light up. The problem is that neither the tubes or ballasts are going to be happy and most likely will have shorter life than they should.
I start seedlings under 2, 4 foot T-12 shop light (full spectrum "sunlight") fixtures, per shelf. The shelving system is a 5 shelf metal "metro rack" from Lowe's (Sam's Club and others have them in 2 to 5 shelf arrangements). I have 2, 4 flat heat mats with thermostats to control bottom heat. The chains attached to the light fixtures allow me to move the lights up as plants grow, keeping them 2" above the flat and later above the seedlings as they grow. The trays are rotated daily to give all equal light exposure - cuts down on those leaning toward the center. Lights are on 14-16 hours per day. As soon as temps and weather allow, seedlings are moved outside to adjust to "real world" conditions.
The point is well taken about T12 fixtures not being designed for T8 tubes.
Unless I find used T5 fixtures at a Habitat for Humanity "Restore", or a sale on T5s, I'll either keep waiting or jump; on used T12 fixtures if cheap enoguh.
I agree that wood panelling probably would not support 11x21" trays if they hung over the edges of shelves - not with soil and water. But the wood paneling would be a cheap way to add some stiffness to the trays when I have to carry them around.
Often, if I am going to have to move seedlings around much, I'll transfer them to a smallish corrugated cardboard box lined with plastic film. Smaller and stiffer and I don;t care if they crack. But they can't take being rained on!
If you check on the Lowe's website for the T8 fluorescent light fixture, one shows just T8 and another, the same product number, shows for T8 & T12. I double checked it because it threw me for a second. It does look like the pins will match up, since they're both double-pin tubes, just different diameters. Maybe the older fixtures might have a different ballast that may not work with the newer T8 bulbs.
If I could have anything I wanted for free, I would take 4-tube T5 fixtures and not try to overdrive them.
Since I would not want to replace tubes and ballasts any oftener than necessary, I should give up on the idea of 'extra-bright' fixtures. Find whatever's cheapest, then get enough brightness by packing more of them together.
If the fixture plus tubes costs $30, but you use $10 of electricity per year, "effciency" and long tube life probably save the most money in the long run.
One can see the confusion regarding light output. Here's a link to 48" tubes - they are all 32watts, but each has a different kelvin. As I understand it, one should choose a tube with an output of 6,500K for indoor growing purposes. (I've not used this company, just using their site for information)
Some hobbyists posted schematics for wiring ballasts innapropriately, like a 4-tube ballast wired to 2 tubes. The extra power makes the tubes brighter, warmer, and shorter-lived. And you take your chances on getting it right enough that you don't burn your house down!
The "6500 K" color might be on the blue side, but I see sources that call it "full specturm".
A really red tube would be 3000K ... but I think that is specialized for flowering, not our usual concern.
The first link seemed to be all T8 tubes. 32 W and 2800 lumens would be 87.5 Watts per lumen - almost as good as T5 high output tubes.
Here are so0me T5 tubes ... try "Find by wattage range" and 54, 39, 35 or 28 Watts.
I do the same thing. I bring several plants in to overwinter in my Southern windows.
At this point I have moved most of my seedlings to their bed, but they are not thriving. I don't know what the problem is. Too cold? My cucumbers look very pale and nothing is growing very much. I amended the bed with composted manure ,but I did not add fertilizer when I planted. I just added some to help them along.