How many hours of sunlight will the plants get on the porch? What about days when the temps stay in the 40s?

Mike

I figure 4-6 hours of sunlight through the windows, and the average temp for mid to late May in Mpls is 58-64 degrees or so. One thought I had was if I knew it would be a nice day Id put the shelves outside with a vented clear, vented plastic with an opaque top (I read in some of these forums that the noontime direct sun can burn the seedlings pretty good). I'm wondering if 5 hours of real sun = or is close to 12 hrs of shoplights.

It's way more light, that is, if it is a bright sun.

Mike

That is not enough sun at all.

Think of the summer sun.... 14+ hour days at a different angle, which is MUCH more intense then the sun light we are getting now.

Your plants need 14-16 hours of 'shoplights' from now, till they get outside. They probably won't die, but I don't think you will be able to sell puny, leggy plants.

And you are correct, seedlings can not take direct sunlight. That process is called 'hardening off'. When you take your plants outside in the Spring and set them out in the shade for a 1/2 day and bring them back in. You keep repeating this for longer amounts of time and more sun over 2 weeks and they are ready to go.

Peppers like warm temps so they will not do very well on your sun porch... I would keep those inside under lights. Is there any way you can add a few more shelves? I can fit 16- 3.5" pots in a 1020 tray. Maybe you can try deeper and less wide transplant containers to get more under your lights? Maybe in Mid May you can use your sun porch but I would not use it for more than 2 weeks.

I hope that helps.

Keriann~

Keriann,

Wrong. Period. Decent sunlight at this time of the year will provide 12 mols of energy over a five hour period - more than enough to grow seedlings. Yes, there may be a problem with the other 19 hours but if the temps are not hot, the potting mix is a bit on the dry side and the OP doesn't add a bunch of nuits, there is no reason the plants will be leggy.

YMMV

Mike

Again, my opinion and what has worked for me...... and I don't agree with the 'not hot temps' as well. That sounds like a recipe for dampening off. I have been very successful with shoplights, ~50-60 degrees and no sunlight.

To each their own.

Keriann~

I guess the question is, will the transplanted tom and pepper plants be ok in my sunporch or do they have to stay in the growroom with 12 hr lights?

You might get away with it if you keep the daytime temperature lower than the nighttime temperature because that is reputed keep plants short. That can be accomplished by opening the window and closing the door to the rest of the house during the day and closing the window and opening the door at night. But, that will also slow growth and you will need a longer time to get the plants to fill the pot.

As far as temp goes, the room does get warm as it warms up. I can open a screen door a bit and try to regulate this a bit. Does anyone have any more specific temperature ideas? If I leave everything closed it probably will get as hot as 80 on warmer days (in May). My idea is to have a bit of portability too soo if a night is going to get real cold I could move stuff in. Before I set up I was going to set up a digital thermometer in order to test what the temp range might be on various days/nights.

I really appreciate all the ideas and help.

Perhaps Keriann doesn't understand the relationship between cooler temps and compact growth or that 'damping off' is a result of excessive water?

minn 65 is a good temp for your seedlings and they should do fine with 5 hours of sun.

Yes, I understand cooler temps promote slow, compact growth.

Dampening off is due to mostly over watering problems but also, stress put on the seedlings from poor light, too warm of temps and bad air circulation. None of these have precise numbers, these all must be tweaked in order to achieve the results you are looking for or what your constraints are.

I cannot recommend using sunlight and warmer temps (65+). I tried that method along side 14 hour shoplights and ~50 temps and my seedlings were much more compact, bushier and stronger than the ones in the sun. Up here in WI we get about 6 hours of Âokay sunlight but March and April bring many cloudy days. My seedlings in my North window were leggy and scrawny.. thin weak stems and leaves. They were also much harder to keep watered adequately. The seedlings under my shop light were easy to maintain and looked beautiful in the Spring.

If you do not have any room under lights, I would recommend putting any cold crop seedlings into a cold frame (peppers and tomatoes will not like a cold frame though). You can search for cold frames in the forums and it will allow you to get more space for your seedlings.

These forums are about helping others from what has worked for me. This is what has worked for me so I am not Âwrong or right for that matter, it is just that this method has given me great results. I am always trying new things from light spectrums, to different soil mediums, to indoor/cold frame direct sowing techniques.

Happy Gardening

Keriann~

My point was that higher night time temperatures cause plants to become shorter. That is the exact opposite of what naturally happens. I read it in a horticultural journal but never tried it.

Hmmm that is very interesting. I may have to try that with my Hollyhocks this year.

Does your lighting change or just lights on- cooler and lights off warmer?

keriann~