Shop Products
Houzz Logo Print
easychair_gw

Using grow lights in ordinary lamps?

easychair
18 years ago

I just saw a video by Jerry Baker in which he mentions to put grow lights into all of your lamps in your home for supplementing natural light coming through windows. But he also mentions that plants only grow when the sun goes down, so why would it be good for the plants to receive light, even that of good quality, at night which is when most of my lights would be turned on?

Also, if I were to do this, which inexpensive bulbs would you recommend. Thanks,

Jeff

Comments (10)

  • nygardener
    18 years ago
    last modified: 9 years ago

    There are "natural daylight" bulbs, sold in most lighting stores, that provide light closer to the natural spectrum mostly because of its cheering effect on people, not plants. Grow lights of ordinary household wattages are most useful when they're very close to the plant foliage and not screened by fixtures or lampshades. If any of your lamps fit that description, compact fluorescent "cool-white" bulbs are probably your best and most economical bet.

  • shrubs_n_bulbs
    18 years ago
    last modified: 9 years ago

    Jeff, you are halfway to realising that Mr. Baker is talking a load of rubbish. The amount of light you get from this type of bulb is negligible, you'd be better moving the plant an inch closer to the window. You would need to put them really close to the plant, but they put out too much heat. The "daylight" spectrum is a little better for the plants, if there were enough light to make any difference, but you probably won't like the way they look. Try one and see what you think if you don't mind paying $5-$10 for one light bulb, some people like that shade of white.

    You could leave the lights turned on all day, but you'd be burning money and adding almost nothing to what came through the window. Using them during the evening might help the plants a little or it might harm them. Continuous low levels of light are actually harmful to plants. They need periods of bright light mixed with periods of dark or near dark.

    Plants have two distinct phases in their metabolism, one in bright light where they are making sugars from sunlight and carbon dioxide, and one in the dark where they are burning those sugars in a very similar way to animal metabolisms. It isn't strictly true to say that plants only grow at night but it is an important part of their metabolism. At one particular level of light, all the sugars produced by photosynthesis are burned by respiration and the plant cannot grow. For houseplants, this light level is very dim, but for many plants it is brighter than indoor lighting and the plant would die indoors.

    Jerry Baker should know better than to offer half-assed advice to spend loads of money on these light bulbs. Did I say that? He's a better salesman than a gardener.

  • easychair
    Original Author
    18 years ago
    last modified: 9 years ago

    Very interesting information. I won't be going out of my way to buy special bulbs to supplement the light coming from my big eastern window.
    Thanks you two. So shrubs n bulbs, is it best to have the plants in total darkness at night than to have any night lights on? At what dimness/brightness will the plants suffer at night? Or is it silly to consider this stuff?
    Jeff

  • zink
    18 years ago
    last modified: 9 years ago

    Jeff,

    Lower levels of light at night will not harm a plant at all. Your only consideration is that if you are growing a flowering plant that requires a dark phase to bloom, your night light may prevent that from happening. That is it.

    Shrubs_n_Bulbs, and nygardener, are correct about Mr. Bakers advice. It is useless to the plant. I assume Mr. Baker is talking about the "blue-tinted" bulbs. Those are neodymium coated incandescent bulbs. The neodymium filters out 15-20% of the light spectrum in the YELLOW range. This brings the overall color temperature closer to that of average sunlight, but still does not replicate any actual "daylight" spectrum from the sun. I say "any" spectrum, because the light spectrum from the sun actually depends on the time-of-day, season-of-year, location-on-the-planet, cloud cover and a few other atmospheric variables. Matching the COLOR TEMPERATURE is about all the lamp manufacturers can ever hope to do. Marketing folks, on the other hand, can hype up any spectrum they can get you to imagine.

    Now see below for the INFORMATION EVERYONE HAS CONFUSED > Light and Dark!

    There are 3 distinct processes I want to discuss:
    PHOTOSYNTHESIS
    RESPIRATION
    GROWTH

    PHOTOSYNTHESIS has two phases, which have usually been called the LIGHT cycle and the DARK cycle. This is very misleading! Why? Because BOTH of these processes happen during photosynthesis! They occur together and NEVER at night. Why have they been called LIGHT and DARK? Because the first cycle is a "photo-chemical" reaction, using a photon as the catalyst. The second cycle is a "biochemical" reaction, using an enzyme as the catalyst therefore it is "dark". But this will obviously NEVER happen in the dark, as it occurs during photosynthesis. Good biology books refer to these two cycles as the Krebs Cycle (photon) and the Calvin Cycle (enzyme).

    During PHOTOSYNTHESIS, sugars are produced and so is OXYGEN! The Krebs/Calvin cycles both consume AND produce both O2 and CO2, but overall, they produce much more O2 during photosynthesis than CO2, while using more CO2 than O2.

    RESPIRATION is occurring all of the time, at all hours, and involves many kinds of transport and exchange of chemicals/elements/gasses. Respiration is a primary consumer of the sugars produced by photosynthesis, but respiration also uses up other chemicals to fuel the process. While respirating, the plant is absorbing CO2. The most important thing about respiration is that the plant must produce enough sugars during photosynthesis to support respiration AND have enough sugars left over for growth. The plant will use its fuel for respiration first, before allowing any leftover sugars to be used for new matter.

    GROWTH is the result of having sugars leftover from the respiration process. If the photosynthesis process is not producing enough sugars to support respiration, there is what is called the Compensation Point, at which death begins to occur. Growth actually occurs at all hours, whenever there are enough sugars available to support it.

    I have read that plant growth (also called the production of dry matter) is more vigorous at night. This is attributed to 2 factors:
    1) It is usually cooler at night, which reduces the rate of respiration, increasing sugar availability.
    2) There is less water stress at night, compared to the daytime activity of the photosynthesis and its support systems functions

    So, PHOTOSYNTHESIS produces sugars, RESPIRATION uses them up, and GROWTH gets the leftovers.

    Zink

  • necro1234
    18 years ago
    last modified: 9 years ago

    Hi guys

    Just curious, Im growing alotof CP's, I have them indoors on a heavily shaded windowsill, Im using 2 X 40 watt Verilux grow lights placed about 8" above the plants (flurecent bulbs)

    Reading what you have said, how much benefit to the plants would these bulbs really be?

    Thanx

    Sheldon

  • easychair
    Original Author
    18 years ago
    last modified: 9 years ago

    Thanks for the lesson Zink! It really clarifies things.
    jeff

  • nygardener
    18 years ago
    last modified: 9 years ago

    Sheldon - What are CP's? Your lighting setup sounds good as a supplement to daylight for plants that have fairy low light requirements that's because you're using bare bulbs and have them quite close to the foliage. The same wattage 8 feet away (as for a centrally-located ceiling fixture), rather than 8 inches away, would provide less than 1% as much light.

    I have a pothos (a low-light plant) growing on a tall shelf that's a couple of feet away from a 25-watt cool-white compact fluorescent bulb installed in an unshaded overhead fixture, which I leave on during daylight hours (and continuously when I'm away), in a narrow hallway painted white. The plant's been growing happily for a couple of years with that light source alone.

  • shrubs_n_bulbs
    18 years ago
    last modified: 9 years ago

    CP: Carnivorous Plant.

    In addition to what Bill said, your 2x40W bulbs are equivalent to about 400W of the incandescent bulbs referred to in the original Jerry Baker question, more than most people would have for an entire room. 400W of incandescents at 8" would of course fry almost any plant.

  • shrubs_n_bulbs
    18 years ago
    last modified: 9 years ago

    I just got around to reading Zink's botany lesson in detail. I knew it would be correct and kind of skipped over it (sorry Zink) :)

    The comment that While respirating, the plant is absorbing CO2 might be a little misleading. During respiration, plant leaves absorb oxygen and convert it to carbon dioxide just as in animal respiration. Water is also produced just as in animal respiration. Respiration reverses many of the effects of photosynthesis, but it is not simply a waste. Respiration has been shown to have benefits for plants (plants do less well if respiration is blocked), but the reasons why are not well understood. One known and obvious benefit of respiration is that ATP is produced by the breakdown of glucose, again just as in animals, and ATP is the primary provider of energy for internal processes. It is worth noting that the Krebs Cycle is in fact respiration, although only one possible chemical means by which respiration can occur.

    The regulation of plant growth is a complex process, not just dependant on the availability of water, sugars, and energy (ATP). Two of the hormones involved and studied in detail are auxins and phytochrome.

    Auxins stimulate many types of growth. They are responsible for much of the reactions of plants to different light levels, such as stretching in dim light and bending towards light. Auxins move away from illuminated portions of the plant. This effect means that in the dark auxins move to all parts of the plant cells, the cells then elongate and the plant appears to grow even if it is not actually increasing in mass.

    Phytochrome is a hormone which changes form during the day into a type that suppresses stem elongation and encourages branching, leaf production, and flowering. This form is converted back late in the day and during the night, causing stems to elongate more at night. Phytochrome is strongly involved in regulating processes that depend on day length such as flowering and dormancies.

  • necro1234
    18 years ago
    last modified: 9 years ago

    Wow, thank you guys

    Ye I got some Fly Traps, Butterworts and some Sundews growing under them.
    The Sundews seem very happy from their coloring while the Flytraps seem happy enough, their coloring shows that they are getting good light but would not mind getting more (the traps are about 80% covered in red pigment)

    Once again thanx alot!!

    Sheldon

Sponsored
Michael Nash Design, Build & Homes
Average rating: 4.9 out of 5 stars254 Reviews
Northern Virginia Design Build Firm | 18x Best of Houzz