How long are fluorescent lights effective on seedlings?

Some of my flower (specifically, Monarda - but soon other) seedlings started in jiffy PELLETS and raised under fluorescents are needing to be transplanted - that is, roots are exceeding the webbing of the pellets.

This means my seedlings will now occupy double/triple the space under the fluorescent lights, and that means I have to go buy three times the number of lights I now have UNLESS the need for those lights has now passed and I can stick them in my mini-greenhouse and let daylight suffice - although we are currently getting only 12 hours of daylight.

What should I do? This is the first time in my life that I've grown healthy-looking seedlings and I DON'T want to blow it now!!!

That is one of the problems with starting seeds too early. Have you got a cold frame? This would be a good next step - hardening off. If you take them outdoors be aware of wind and too much sun - it can quickly dry out the soil and burn the leaves.

In my defense, the seed package SAID start them 8-10 weeks before the last frost date, which I did! I RESISTED (and if you knew me, you would know the restraint this took) starting those seeds labeled '6-8 weeks before the last frost.'

I THINK my mini greenhouse is functioning like a cold frame. I was thinking about moving the transplanted guys out there and heating it to 50 degrees on cold nights in order to avoid carrying them in and out of the house every day.

Thank you for answering so quickly!!!

I start seeds with the Jiffy 7's. I find the hardest part of growing them under lights is this: When the roots start coming out, they need to be in soil. This is what I do : I get a small 4 x 4 container, put good potting soil in the bottom, then the Jiffy 7, then more soil and make it snug. As it grows, all the other seedlings will be growing too and you'll have to find places to put them. They have to have just as much light as they did when they were emerging seedlings. Keep adjusting your lights to optimize the rays on the containers. They must have 14-16 hrs. a day for best growth and strrength. I don't think I would put them outside now as they have been started inside. Way too early outside!! But, if you had started them outside. you could have them there. This is my first season to sow outside. I don't see any germination yet, but have hopes that they will come up sooner or later.

Karin ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Karin, thank you.

So does this mean that I will need to keep the seedlings under the lights until it's time to harden them off after frost?

Debi,

I would keep them inside as long as you can.

Here is my experience with my greenhouse:
I used to have a greenhouse. I started my seeds under lights. When I ran out of room, (space) then I would transfer them to bigger containers. I could regulate the fan in the greenhouse to give them fresh air when I had to, also water them without any trouble. But what I couldn't do in the greenhouse was control the light to any degree. All the transplants, bar none, got spindly and couldn't stand up without props. I blame the fact that the plants did not have strong enough light between the time I brought them out -- to the time they went in the ground. Now some plants, I could cut the top sections and they didn't look too bad, but I have myself to blame for the results. 8-(

Karin ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I would guess your last frost date would be similar to ours - April 15th which is about 8 weeks. But then two years ago we were in the teens mid - April.

I know what you mean by restraint - I'd always have hundreds of seedlings ready to set out -sometimes set out too early and we would get a freeze overnight or a little late and the weather turns to hot, dry, and windy and that was just as bad. So now I sow direct in the pot or ground where they will grow for the summer - not always successful but a lot less stress of transplanting.

How far along are your seedlings? I agree with greenthumb on potting them up to a bigger pot if the roots are growing outside the mesh and do cover the top of the mesh since this will act as a wick. Sometimes the mesh is a problem for certain plants - I haven't used it in a few years.