A Guide to Indoor Lighting for Plants, The Bonsai Zone, Jan 2019

Connor from the KW bonsai society gives an excellent presentation on indoor grow lights! Follow KW bonsai on Facebook…..


  1. Lots of great information, thanks for preparing this! Is it at all possible to link to a PDF of your slides so that I can reference them easier for the future?

  2. What a fantastic and interesting presentation! Please thank Connor for sharing his research. It was well done and bravo for the way he kept his cool at the end. Thanks for sharing this on your channel, Nigel.

  3. You could just take automobile lights if you want HID lightening on the cheap. Come up with a 12 volt transformer a reflector assmebly… all ebay materials. LEDS are more effiecient of course.

  4. This presentation is certainly one of the best if not THE best on the subject. Thank you, Nigel and Connor. I have a couple of comments based upon my career experience with providing artificial light to plants.
    —It appeared to me that Connor’s expertise was thorough except with his pronunciation of some of the botanical terms such as
    cytokinins, phototropism and several others.
    —Just to emphasize Connor’s point….to date, artificial light can only be a supplement to sunlight.
    —Nothing was said as to the distance the artificial light source has to be from the plant’s foliage. A crucial factor.
    —In my experience, the red/blue LEDs work out experimentally to give better results than the full spectrum LEDs. I don’t have an
    explanation for this it just has proven out over and over again with my plants. The COBs are new to me and so I am interested in
    testing them out.
    —I think the number of types units used to measure light (lux, lumens, ft-candles, PAR…etc) and it’s properties is confusing in this
    presentation and should be standardized to PAR units…for a number of reasons too numerous and requiring too much explanation to
    be included here.
    Thank you, both, again for this presentation. Really terrific.

  5. So there was one thing Connor got wrong about white led’s. A long time ago, yes, there was a white led that was just a combination of red/green/blue. However, virtually all white leds are actually a deep blue color led (near uv) and it’s coated with phosphors (the yellow film). This yellow phosphor coating fluoresces from the blue led and refracts light that appears white. Depending on the type of phosphor used is what determines the spectral output on the Kelvin scale. If a white led has a phosphor coating that appears light yellow, the output is likely going to be at or above 5000k. If the coating appears gold or orange, it’s likely going to be 3000k or lower.

    In fact, the reason why we call fluorescent lights, “fluorescent”, is because it’s concept is exactly the same as a white led. A fluorescent bulb or tube houses a gas that when excited, glows blue. Which is UV light. Just like the white led, there is a phosphor coating. It’s on the inside of the glass and this is what gives the bulb it’s white color. All fluorescent lights are actually uv lamps that just have a phosphor coating which “fluoresces.” The only real difference between fluorescent house lights and dangerous germicidal uv lights is that germicidal lights have no phosphor coating and are made of quartz glass which allows for uv-c to pass through.

    So knowing this, the fun fact is that a white led and a fluorescent light are in fact the exact same thing when comparing physically how they create white light. It’s actually technically accurate to call a white led a “fluorescent” light. But we don’t because that would confuse people.

    So to simplify, if you wipe the white powder off the inside of a fluorescent light , it will glow dim blue. If you remove the yellow coating off a white led, it will glow blue. The fluorescence that occurs is the same as being under a black light and looking at your white shirt or a highlighter pen and seeing it glow.

  6. Nigel Saunders, in Part 6 of this series, you consider using Jade (Crassula Ovata) in your soil and suppose it would've been too big to start with. I would've liked to see you use Jade, personally…I think it could be a fun idea to place just 1 Jade leaf on the soil (as if fallen accidentally) and watch it grow from that leaf into a new plant (Since that is how they propagate.)

  7. Amazing. I’m currently preparing to move into a new house so I was planning to buy new lights and this was very helpful! Thanks! Also I am gonna send you viewer’s pics after moving. Cuz I haven’t seen any Korean viewer’s pics yet sooooo thanks again, such an informative vid:)

  8. Awesome presentation…thanks for sharing! Nigel/Connor: How does the Aspect Grow Light from Soltech Solutions stack up based on your recommendations? I just moved into a new office at work and I'd like to incorporate some of my trees (that were already being grown in a different south facing part of the building). I have T5's overhead and a west facing window in this new space and I'm looking for a grow light to optimize conditions. Thanks!

  9. Who would’ve thought that pot growers are growing our ability’s as bonsai enthusiasts to grow high light requiring plants indoors and in the future we might really need this when natural disasters hit us so we can grow food when the sun is gone. Maybe we could put a massive light on our moon once the sun dies so we can survive lol. Thanks for sharing and good job Connor!

  10. Excellent Connor is spot on.. our channel has stressed and adressed this so many times, the importance of light and understanding about how light works for bonsai trees, especially indoor bonsai. Canada and Sweden beeing very close in latitude in our northern hemisphere i can agree with every argument and technical data. The real challenge (from experience and knowledge) as we see it is to get the right levels of humidity and at the same time keep sustainable levels of low heat in the room.. low humidity is the real problem factor, there for unheated rooms or garages with weak heat on, in combination with some draught or ventilation is the best we have figured out lightsources can always be fixed, there is tons of options. Also you learn with time that some species just can't make it in an micro envirnoment, even tho they are classified as tropical/semitropicals or not… that's bonsai i guess.

  11. Wow Conner went into such a great depth on how light effects plants. I’m going to have to watch this a couple times with a notepad for notes, just to absorb all this information. Thanks Conner for the presentation and thanks Nigel for sharing with us.

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