Why the window sill hate?

Question- I've seen some posts advising against trying to start seeds next to a window sill. Which happens to be the setup I've got going now- Fluorescent lights, and a big window with mucho light coming in and my seeds and seedlings right next to it. Is it too much light? Or is it maybe too much temperature variation? It does get down to ~65*F at night next to the window.....

Thanks!

I think the big objections to windowsills are the temperature extremes (too hot during the day, too cold at night) and not enough sunlight.

If you've got fluorescent lights to augment the natural light, and your plants aren't too tender for the temperature swings, it's probably okay.

Is the sun shining right on the trays? I have tried it and found that the sun will cook the seedlings and dry them out too fast! If you can maintain the water, maybe you'll be OK.

When I advise against windowsills, it's mostly for people wanting to know if they need to use a shop light or if the light coming in through a window will be good enough... Bright as it may look to us, sunlight coming through a window is nowhere near as bright as sunlight outside, and you'll get sturdier seedlings if you grow them under lights, either instead of or in addition to window light.

And has been said, direct sun can cook little seedlings, especially if you've got them under a humidity dome -- real greenhouses use vents and fans to keep things from getting too hot, and the humidity dome acts like a greenhouse cover.

Nice. Ok good answers. I do have both working pretty good right now (fluoro. lights & sunlight from the window) and I have an auto watering capillary type system keeping them nice and moist. So I think i'm ok. The only problem I have had is some of the seedling are getting some fungus on them - so i'm pretty sure they're goners. But the other 75% are good. So i'm pretty satisfied for my fist time :)

Thanks!

mak90, did you sterilize your soil and the container they are growing in? also when you moisten the soil put a drop or 2 of dish soap in the water. try spraying the fungus with hydrogen peroxide, and surrounding soil. the white fungus could be from dust mites. Jim

I have seedlings growing in a mini greenhouse inside..and am doing very well,some also under shop lights..I have 4 running constantly..I do swap them around,I have wonderful south windows so they get full sun all day,I DO have to open the greenhouse about 10am or they will cook,(been there done that)..I keep lots of my older full sun house plants and tropical plants too...in my south window,but seedking you will have to turn more often and if they don't get enough sun they get(leggy)..if thats starts happening I moove the under the lights only a couple inches over the top of them...slows them from reaching..tomatoes really do it the worst of everything I have ever planted..I did real good with my peppers and tropicals from seed in the windows..just remember if that's the only place you have go for it I do...lol..I have to have my seedling fixes..heehee

I'm not sure why, but I found that fungus is not a problem when I have a fan circulating the air (not blowing directly on the seedlings). Of course, my setup is in the basement in my laundry area, so the humidity is probably a bit high. I started out this time without the fan & noticed fungus on the soil. The problem was cleared up the next day after using the fan.

I'll remember the hydrogen peroxide tip. I always have some on hand.