Grow Lights

[Mike Maurer]

Originally Posted by Fusion_power

You can leave plants under grow lights 24/7 but it actually suppresses growth. Plants need a photo period to accumulate sugars and a dark period to expend them in growing.

My light stand holds 36 fluorescent 4 ft bulbs and can accomodate up to 30 standard trays 11" X 22" at a time. I usually turn the lights on and leave them on for about a month when I start tomato seedlings. I have up to 60 trays of plants and every 12 hours I swap the 30 trays that are under the lights with the 30 trays that are sitting on top of the lights. There is a big reason for handling each tray this many times. It allows me to look at every cell and seedling to see what is going on with the plants and from holding the tray I can tell if water is needed. I can handle the plants this way and totally avoid over watering or under watering either of which can kill thousands of seedlings in a matter of hours.

Once the seedlings are about 4 inches tall, I move them to the greenhouse and transplant into individual trays of cells. This is a fairly efficent way to produce about 50,000 seedlings in a year.

DarJones

I have looked for a reference to how long I should leave seedlings under the lights. You mentioned 4" and someone mentioned 2-3 weeks. How long is the recommended time?
Thanks, Mike