Instructables

Will this light work to grow plants in my homemade greenhouse?

I am working on a homemade greenhouse and I wanted to use a solar light, I found one for pretty cheap at harbor freight:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=95573
will this work to help my plants grow? or does it have to be a certain type of light? thanks


solarmatrix4 years ago
Most plants are particularly sensitive to orange/red and blue spectrum light hense the availability of led grow lights.
blue is used primarily for growth, red is used for flowering.
Google plant spectrum and see.
There is of  course small variation between species of plants.
High powered (3-5watt) leds, the number of which would be determined by the area lit and the species requirements, are very efficient for plant growth as they dont produce the spectrums the plants dont use much.
One single garden light would not really help plant growth although nice for display of the plants. A good idea that with a bit more investment/research would work well.
davej6694 (author) 4 years ago
i ended up getting some really bright blue LEDs for pretty cheap so it worked out i guess theres like 20 of em in there
seandogue4 years ago
Probably not. It is a very low output lamp. It might *assist, but as a primary...no way, unless you mean to grow one or two little herb plants, and I mean herb plants.
davej6694 (author)  seandogue4 years ago
well they would get the light from the sun during the day then this at night.... Is it worth spending 20$ on or should I find something else? maybe LEDs or something?
I'm not sure how many plants we're talking about. a 5W lamp isn't going to really be effective for much more than a pair of very small plants.

I'd say it's probably not worth it. The light you pointed to looks more like a general purpose utility lamp...It would be nice for working in the environment during the early evening, after the sun has gone down, but imo not so much for actually instigating solid growth.
jeff-o4 years ago
Probably not.  It won't really be bright enough (as others have said), but it also isn't full spectrum, a key feature that plants really need. 

You could use LEDs, but they aren't much more efficient than fluorescent lights (so you'd get the same light output).

If you want something useful, you'll need to upgrade to a larger system, one that can support a few 3' or 4' long full-spectrum fluorescent bulbs.
I'm no gardening expert, but I very much doubt that your plants will even notice when the light is on. It's listed as the equivalent of a 30 watt incandescent, which is just enough light to keep you from bumping into stuff in the dark. I'd also be very surprised if it produces even an approximation of the same spectrum as a grow light. I'm gonna say "not likely".