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Supplemental Lighting Advice Please

Posted by briana_2006 IL (My Page) on
Sat, Jun 12, 10 at 20:07

Hello all -

I have a large number of different types of plants that I would like to overwinter inside this year. I could fill a 9 foot by 12 foot space easily.
I am debating on what type of system to get - HID or fluorescent.

It seems high intensity discharge is the way to go especially if you use an in-line fan to cool the reflector housing and a fan near the plants to cool the plant area so that the lights can be brought even closer to the plant canopy (heat dissipated)--taking advantage of the higher lumen output of the HID's.

I am debating between A 1000 watt/400 watt HID system with an electronic ballast and either a compact fluorescent or 4 foot linear tube T5 set up.

I have read that the electronic ballast is better because it allows more lumen output from the bulbs.

I initially favored fluorescent bulbs because they burn much cooler compared to the metal halides and tended to shy away from the metal halides because of the possibility of a 'non-passive' end of life event. However, it seems the non-passive events are rare especially if the lamps are changed out slightly before the end of their rated life and even if it were to occur, the optional tempered glass shield (which I would get) on the reflector would contain any hot glass/mercury and not allow either to escape into the environment eliminating the risk of fire or creating a toxic mercury environment in my basement.

Fluorescents (HO T5's) I am told by some can provide enough light providing the light source is very close to the plants to allow plants to grow well (short nodes between leaves) and even flower/fruit (using both cool and warm bulbs)-- others say no you must have HID to achieve this.

I once used a cheap ($20) two bulb fluorescent fixture - 4 foot linear tubes - cool white ~ 2300-2600 lumens, I believe, a number of years ago to try to grow basil, oregano, etc, in a window box planter. I had the light close to the plants but had dismal results -- only 1 out of about 5 plants survived for an extended period of time.

I would love to hear other peoples experience with either HID or fluorescent or both of these systems.


Follow-Up Postings:

RE: Supplemental Lighting Advice Please


Google Daily Light Integral. Get a light meter. Then you will have the answers you need.


RE: Supplemental Lighting Advice Please

Hi Briana! I've never used the HID fixtures, but I have used an 8-bulb HO T-5 fixture with great success, growing plumeria all winter long. Plumeria normally go dormant in winter months, but I have kept them growing without any break in their growth cycle, and have actually had them bloom. Since plumeria require a lot of light to bloom, I've been totally happy with the T-5 florescent lights. Here's a couple of pics.

Winter plummies 2


This lighting system does a great job with starting seeds, and cuttings. Here is a picture of a 2 month old plumeria cutting that was nothing more than a stick with no leaves when I planted it. Look at it now!

2 month old plumeria cutting

RE: Supplemental Lighting Advice Please

Very impressive Arctictropical, and zone 4! I am going to also try overwintering elephant ears and canna this year. Is it doable with regular fluorescents (not HO's)? In a basement that is not much higher than 55F in the winter? Maybe not eh?

Also - I assume your lovely flowering plants are located where you can enjoy them, not stuck in a basement?

RE: Supplemental Lighting Advice Please

"Fluorescents (HO T5's) I am told by some can provide enough light providing the light source is very close to the plants to allow plants to grow well (short nodes between leaves) and even flower/fruit (using both cool and warm bulbs)"

This is true. The reason others oppose this setup is because HID lighting gives you better yield and so HO fluoros seem like a waste of time for them. However, you'll be more than happy with HO fluros if you utilize them correctly. DLI (Daily Light Integral) is important. I recommend 4 to 6 HO bulbs split amongst two units. A great benefit of HO fluros is the decreased electricity costs in addition to what you mentioned.

RE: Supplemental Lighting Advice (Amended)

Correction: 4 to 6 bulbs of HO fluros (54-watts per bulb) will happily support 4 to 6 mature fruiting plants in a 4x3 area approx.

For a 9x12 area, you'll need some more juice for the mature plants. I like HPS Hortilux units. However, it's wise to have a separate area for reering seedlings via fluoresecents.

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