Another observation on LED Lighting

Posted by Bruce Pearson on 8/5/2017

Another observation on LED Lighting


LED lighting for my violets in South Florida I have found to be equal if not superior to flourescent lighting.  


Let me state that I am certainly not a lighting engineer, but have degrees in biology and ornamental horticulture.  I have been in the nursery business since 1962 and grown plants since I was 6 or 7. 


I have grown violets under both flourescent and LED lighting for a little over 3 years, and certainly not an expert.   We grow not for show but for our garden center and internet sales.  The following are  facts and observations I have made.


There are a number of types of LED.  I use mostly 48" aquarium lights with red, white, green and blue bulbs.    They have 3 rows of parallel lights in the unit Interestingly, I have some with only blue and white, and see little difference if any in growth habit.  With LED lighting being able to support coral growth in aquairums, I feel the technology there is certainly enough to support African violet growth. 


Although I really have no interest in growing for show, I am sure LED grown plants from us would certainly qualify for blue ribbon status, and if time and effort  were taken to produce a best in show, I would guess our LED produced plants would win out over our flourescents. 


Long time, experienced, best in show winning growers have necessarily started with flourescents and have learned to grow under them.  So they have little need to fix what is not broken, but I bet in the near future with new hobbyists coming on, the majority of best in shows will be from LED fixtures and flourescent lighting will take a distant back seat. 


To be fair, we have only one Flora-cart unit with flourescent bulbs, and these bulbs are older than a year probably 3 to 5 years.  I find that although the plants appear the same from casual observation to our LED lit violets (over 100 strips)  the root system is superior on the LED lit ones. 


About half of our LED lighted violets receive some natural sunlight.  The other half are strictly LED.  Timers  go off during periods of bright sunlight during the afternoon when they receive good light from the sun, and then set to come back on in late afternoon and into the evening.  The ones not benefitting from natural light get between 12 and 14 hours of LED light. 


Members of our local violet club are amazed at the growth, size of leaves and plants, as well as quantity and size of flowers we are growing.  Our miniature and semi

miniatures are almost always covered in blooms.

Although LED plant lights are a bit more expensive t(48"ones are between $45 and $70) than flourescents, they rapidly pay for themselves in electricity and cost of flourescent bulb and ballast replacement.  With well over 100 light strips in total, I see no difference in our electric bill.  In fact it has gone down since replacing our pool pump with a variable speed pump, all the while adding more lights. 


They produce little to no heat, a plus when air conditioning is needed almost year round in South Florida. 


They are light weight and super easy  for an individual to mount on stands, using only   plastic pull ties.


They are much more attractive than bulky flourescents.


Many more LED lights can be plugged into an individual circuit, as compared with flourescent.


There are no bulbs to change and danger of breakage is non existent. 


In a recent article mentioning the LED lighting at Bird Tropicals in Kansas city, I observed the same phenomenon but with a different conclusion.   We went early to Mr. Bird's establishment , which is conducted in a cave.  My main interest for years has been orchids, but could not imagine he could compete with South Florida orchid growers.  I could really not imagine he would have much, and mainly wanted to go to see his Pembroke Welsh Corgies. He has 2 Corgies and we had 10 at the time, now down to 7.   Corgie people have a special bond and we were old friends by the time the big African violet group arrived.   


Walking into the cave I was spell bound with the varieties he was able to grow under LED lighting and in Kansas no less! (Hope I am allowed to say this as I was born in Kansas and grew up in Oklahoma.)   I know first hand how much harder it is to grow plants in the Plains as compared to South Florida.   Not only did he have many species, I had never heard of but genera beyond my knowledge.   He had even received a prestigious FCC award on an orchid, something given out only rarely.   I was awed at his collection. 


Trying to photograph it was another story.  I got the same result as Mr. Lipson's photo in the March - April 2017 issue of AVSA.   I played around with the white balance on my Cannon T3I with little improvement.  I asked several other photographers in the group but they too were having the same result.  My conclusion is the information the cameras were receiving are a photographic issue and not a lighting issue as his plants were beautiful.  


I see this same phenomenon in trying to take pictures of LED lit plants on stands with my own set up.  Having little patience to manipulate the camera settings, I simply take the plants out from under the LED and photograph under natural lighting which my camera has settings for.  The pictures are radically different.  It is simply the way the camera is set to read the type of light.  I do not think most cameras have a white balance setting for LED, and this has nothing to do with use of LED in plant growth. 


In short I love LED and the African violet plants it produces.   At least give it a try. 

But be sure and get the ones that are for plants or aquariums. There are many more choices than with flourescent.  I see where some big growers in California are switching to LED.  The technology is here but will  ineveitably be ever changing.   

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