Grow light 24 x 7? Do plants need to sleep?
 

Hi,

I have some new seedlings growing, but I'm a couple of weeks late planting
them. Can I make up for lost time by running my grow lights longer? Do
plants need a rest (darkness)?

How close should I hang my light? I have a 4 light bulb setup, with 2 grow
bulbs and 2 regular bulbs (cool white maybe). It's your standard 4 bulb -
4 foot ceiling fixture, hanging from a ladder over the plants on the ground.
The plants are about 2-3 inches tall, too many varieties to mention. The
grow bulbs say 12 - 15 inches, but I'm in a hurry! :-)

Cheers,
Jim

Grow light 24 x 7? Do plants need to sleep?
 

Play4aBuck wrote:

Hi,

I have some new seedlings growing, but I'm a couple of weeks late planting
them. Can I make up for lost time by running my grow lights longer? Do
plants need a rest (darkness)?

How close should I hang my light? I have a 4 light bulb setup, with 2 grow
bulbs and 2 regular bulbs (cool white maybe). It's your standard 4 bulb -
4 foot ceiling fixture, hanging from a ladder over the plants on the ground.
The plants are about 2-3 inches tall, too many varieties to mention. The
grow bulbs say 12 - 15 inches, but I'm in a hurry! :-)

You can't really hurry the plants much. However, when warm weather
comes, the late plants tend to catch up with the others. A couple of
weeks is nothing to worry about. (exception: long season plants in a
short season growing area, such as melons in New England. In a case like
that you have to start the plants too early, warm the soil with plastic,
plant the plants too early, protect them with row covers, etc. etc. You
can grow watermelons here but in the normal course of things they mature
in September, when there's no market for watermelon, but I digress...)

Most plants do need periods of darkness. In fact, some plants use
daylength as a trigger for flowering, so you may be forcing them to
flower too early by extending the day length artificially.

Hang the light at the highest point you expect to need (plus a bit to
allow for leggy plants). Place the plants on a stack of newspaper so
that they are as close to the lamps as possible (within 2") -- remember
to allow for some growth. When they get too close, take out some
newspaper to lower the plants. Much easier than raising the lamps. The
newspaper also absorbs excess water. This also allows you to accommodate
plants of different heights with the same lamps. And you have something
to read while working on your plants.

Grow light 24 x 7? Do plants need to sleep?
 

Play4aBuck wrote:

Hi,

I have some new seedlings growing, but I'm a couple of weeks late planting
them. Can I make up for lost time by running my grow lights longer? Do
plants need a rest (darkness)?

Yes. Conversion of sugars to starches in the roots requires darkness.
Allow 8 - 12 hours' sleep per day. Check your newspaper for sunrise and
sunset, set the timer accordingly.

How close should I hang my light? I have a 4 light bulb setup, with 2 grow
bulbs and 2 regular bulbs (cool white maybe). It's your standard 4 bulb -
4 foot ceiling fixture, hanging from a ladder over the plants on the ground.
The plants are about 2-3 inches tall, too many varieties to mention. The
grow bulbs say 12 - 15 inches, but I'm in a hurry! :-)

Assuming those "bulbs" are fluorescent tubes, 2" is right.

Most plants do charge periods of darkness. In fact, some plants use daylength as a activate for flowering, so you may be banishment them to flower too aboriginal by extending the day breadth artificially.