Author Topic: tropical / subtropical seedlings and lighting  (Read 9082 times)

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
tropical / subtropical seedlings and lighting
« on: May 17, 2013, 09:06:47 AM »
Hi, I have not yet built a greenhouse in my house, and I will not have to within 1 year or more, but I wanted to start several tropical fruit trees during autumn-winter (Argentina) and I think the lighting conditions in the room where I can leave the seedlings is not the best. Temp is between 19 C and 21 C.

I'm talking about seeds of:
Campomanesia lineatifolia (I tried direct sunlight here and some first leaves started to dry)
acca sellowiana (not too much problems with direct sun)
psidium cattleianum (no problems in direct sun)
psidium guajava
jaboticaba
etc.

Will these plants grow very poorly in the shade these 4 months till spring? They never take sun. Will they have an etiolated grow?

There are only four months to the end of the danger of frosts, when I can get them outside in september.

Should I try something else? Artificial lighting? Incandescent or fluorescent bulbs? Thanks in advance

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #1 on: May 17, 2013, 01:11:15 PM »
Unless you can provide the seedlings with many hours of direct sunlight indoors during the winter, you'll probably be much better off growing the seedlings under artificial light.

If you're planning on adding a greenhouse within a year or two and you're only growing small seedlings until then, it doesn't make much sense to go with expensive (but more powerful) lights like Metal Halide, High Pressure Sodium or LED...  I would recommend fluorescent lights for you-- they are relatively cheap, easy to find and use, and work well as long as your plants aren't taller than 50cm or so (and you have enough fluorescent tubes).

Incandescent bulbs aren't worth bothering with in my opinion; they are very inefficient, hot, and don't grow plants very well.

   Kevin

fruitlovers

  • Hero Member
  • *****
  • Posts: 15839
  • www.fruitlovers.com
    • USA, Big Island, East Hawaii, Zone 13a
    • View Profile
    • Fruit Lover's Nursery
Re: tropical / subtropical seedlings and lighting
« Reply #2 on: May 17, 2013, 07:05:36 PM »
Kevin gave you good advice already. I would just add that it would be good to set up your fluorescent lights on pulleys so you can adjust the height of the light as the seedlings grow. If you put the fluorsecent lights close to the plants they will not get spindly.
Oscar

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #3 on: May 18, 2013, 01:36:03 AM »
Yes, being able to adjust the height of the lights (or plants) is crucial; with artificial light of any form (some better than others) the light available to the plant drops off quickly and dramatically the further you are from the light bulb. 

With most light bulbs, especially if you have enough wattage to make your plants truly happy, you also have to worry about heat.  If you keep the leaves too close to the lights they will burn; there's always a perfect balance that takes experimentation to find based on each plant type and your particular setup.

The sun is very bright, but very, very far away; moving 1 meter closer to it doesn't make much difference in how much light you get.  But with every artificial light I know of, moving one meter away from the source will mean you can't keep any sun-loving plants happy.

I also always recommend oscillating fans- 1 is good, 2 or even 3 from different angles is better unless the plant is particularly sensitive to wind.  The lack of significant air movement under artificial lights makes any plant "soft" and more likely to suffer damage when it is moved outside.

   Kevin

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #4 on: May 18, 2013, 03:57:11 PM »
Thanks Both! first class help

carraig

  • Member
  • ***
  • Posts: 80
    • View Profile
    • Amber's Edibles
Re: tropical / subtropical seedlings and lighting
« Reply #5 on: May 18, 2013, 08:18:29 PM »
We grow all of our sale stock indoors now that we live in cruddy Kansas City, and have had great luck with T5 fluorescent grow lights.  They don't get too hot so they don't burn the plants.  In order to have enough light when using fluorescent lights, we buy 50cm deep fixtures with 8 bulbs crammed in.  Fluorescents do not work well for large 'full sun' plants.   The fans make a HUGE difference too, even when you start growing your plants in the outdoor greenhouse.  If they aren't exposed to stresses from the wind, they will bend/break very easily if/when they are exposed to the elements.

Regards,
Carraig

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #6 on: May 27, 2013, 10:27:35 PM »
Thanks carraig




now I should put a fan! (just a few ours a day, no?)

In my home I have a very dark room which in turn is cold (the laundry room, on the patio), and to heat it with electricity would be a waste, so I decided to move into my "computer room" most of the seedlings , but here I dont have good light (though there is a window), so I bought lamps.

The first thing that caught my attention was the LED light, I got a device with 3 light bulbs consuming only 3W, amazing!, But happens to be equivalent to a 40w bulb or 600 lumens approx.

It was not enough, so I looked for something more powerful and I opted for a low-consumption equivalent to 150w, and 300w another to test.

The photos are of the equivalent to 300w, consumes 65w, which is not a waste and I can leave it on all day if I want. It is equivalent to 4500 lumens, I hope the seedlings feel happy in here at temperatures between 19 C and 24 C with this new lamp, there are many guavas, Arazas, palillo (chamba), jaboticabas, camu-camu and other interesting things that should germinate and grow.

« Last Edit: May 27, 2013, 10:32:38 PM by huertasurbanas »

KarenRei

  • Arctic Member
  • Hero Member
  • *****
  • Posts: 1806
    • Reykjavk, Iceland
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #7 on: May 28, 2013, 08:57:51 AM »
Listen well to CoPlantNut, he knows what he's talking about.  :)  And never, ever use incandescents for growing plants.  For one, your power bill will be absurd, and for another, to produce enough light to matter, you'll produce enough heat to fry your plants.

The ideal light distance from your plants - fluorescent, HPS, or MH - is easily measured with the hand test.  Put your hand where the leaves of your plant would be.  If it feels hot, the lights are too close.  If you can't feel it at all, the plants would appreciate more.  You want your hand to feel slightly warm, as if in direct sunlight. 

Most plants don't care whether your lights are on 24-7, and most of the ones that do care only care during flowering / fruiting.  Since you're almost certainly going to be providing woefully inadequate light, I recommend 24-7.

Have pest control plans in-place for: spider mites, scale, whitefly, and aphids.  You'll probably see nothing for a month or two.  But if you don't do regular inspections and know what to look for, they can get out of control in a hurry.  Read up about each of those pests to know what to look for and how to control them.  Don't count on luck or get complacent, odds are very high that you'll get at least one of them.  Be ready to quarantine, and even to destroy plants if necessary.  The sooner you catch an infestation, the less likely that will be.

Expect your plants to use water at different rates.  Plan watering accordingly.  A hose in-house coming from the faucet will be greatly appreciated with time.  :)

Expect to have to clean up leaves.  Some plants are worse than others.

Quote
The first thing that caught my attention was the LED light, I got a device with 3 light bulbs consuming only 3W, amazing!, But happens to be equivalent to a 40w bulb or 600 lumens approx.

Advertising nonsense.  When it comes to growing plants, you can roughly consider all "watts" the same on HPS, MH, fluorescent, and white LED.  They're not exactly the same, but close enough.  Blue or red LEDs can get you maybe a 1.5x to 2x bonus compared to the wattage, but nothing like the ridiculous claims lots of people make about them (also, I recommend against using only LED, some plants are very frequency sensitive and can have a bad reaction).  And of course, never use incandescent.

Quote
It was not enough, so I looked for something more powerful and I opted for a low-consumption equivalent to 150w, and 300w another to test.

You mean ~35W and 65W - real consumption values.  These incandescent equivalents are pointless because you don't grow plants with incandescents.  65W of electricity  is really nothing for indoor growing.  I use about 400W of electricity per square meter and really could use more.  From that (per square meter) I get about 60W of usable light, and adjusting for PAR equivalences compared to the sun (see later), it's maybe equivalent to 80W of sunlight.  Of that, maybe 60W sunlight-equivalent hits the leaves.  The sun is 1000W per square meter against a perpendicular surface and almost all of the light hits something.  Now, the sun has a capacity factor (clouds, angles, night, etc) of maybe 15% or so, so that's maybe 150W per square meter on average, but you get the picture, it takes a LOT of energy to even come close to that which the sun provides.

Quote
It is equivalent to 4500 lumens,

Lumens are also a bad unit of measure.  The lumen scale greatly rewards green (which humans have the highest sensitivity to) and punishes blue and red (which humans have the least sensitivity to).  Plants are inverted, with the greatest response to red and blue.  The best scale to use for describing light output useful to plants is PAR (photosynthetically active radiation), but very few bulbs give PAR ratings.  The ultimate scale of energy efficiency for bulbs for growing plants is "PAR / Watts".  You could also get a good idea of the efficiency of a bulb by its EQE and then adjust that by its spectrum (EQE = external quantum efficiency: how much energy in equals how much light energy out - no "lumens" correction).  But again, don't expect to see EQE ratings on random lightbulbs. 

Unfortunate, I know.  So I recommend just sticking to a raw watts-to-watts comparison baselined in the ballpark of fluorescents, and taking into account any extenuating circumstances (such as unusually efficient / inefficient bulbs and/or frequency response).  To keep it simple, you can say something like "65 watts fluorescent" or whatnot.

« Last Edit: May 28, 2013, 09:25:56 AM by KarenRei »
J, g er a rkta surnar plntur slandi. Nei, g er ekki klikku. Jja, kannski...

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #8 on: May 28, 2013, 01:47:09 PM »
Oh, thanks KarenRei "Yeah, I'm cultivating plants in southern Iceland. No, I'm not crazy. Well, maybe ...", for sure you are crazy :) , now I know why you have such knowledge about indoors growing.

So, by what you've said, I understand that I am using less than half the luminosity needed per square meter, yes? I'm using 65w FL when needed 150 w FL, right?

Growing more than anything Myrtaceae, will they be ok with light 24/7?

I do not know if it's just optimism, but after a day of using this light all the plants look more cheerful.


CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #9 on: May 28, 2013, 02:19:13 PM »
now I should put a fan! (just a few ours a day, no?)

I leave my fans on continuously; if you're going to turn them off and on I would have them on more than off.

In my home I have a very dark room which in turn is cold (the laundry room, on the patio), and to heat it with electricity would be a waste, so I decided to move into my "computer room" most of the seedlings , but here I dont have good light (though there is a window), so I bought lamps.

If you get enough electric light going, it will heat the room for you!

Quote
The first thing that caught my attention was the LED light, I got a device with 3 light bulbs consuming only 3W, amazing!, But happens to be equivalent to a 40w bulb or 600 lumens approx.

Advertising nonsense.  When it comes to growing plants, you can roughly consider all "watts" the same on HPS, MH, fluorescent, and white LED.  They're not exactly the same, but close enough.  Blue or red LEDs can get you maybe a 1.5x to 2x bonus compared to the wattage, but nothing like the ridiculous claims lots of people make about them (also, I recommend against using only LED, some plants are very frequency sensitive and can have a bad reaction).  And of course, never use incandescent.

Yes, that's advertising nonsense!  I've been growing indoors for 20+ years and tried a number of LED lights and was always disappointed. The 1W and 3W LED chips just aren't intense enough to grow tall plants-- they're kind of like fluorescent lights in that respect.

However, I found an LED light with all 5W LED chips and 16 different spectra and my plants are all loving it.  I like the lights so much that I just joined the company that makes them-- so I may be a little biased, but they're the best lights I've ever used in 20+ years.  I'm only using the LED lights (no other natural or artificial lights) and am using 3200W to cover 12 square meters of growing area, with things blooming and fruiting like mad.  I could probably still use a little more light though...

Quote
Quote
It is equivalent to 4500 lumens,

Lumens are also a bad unit of measure.  The lumen scale greatly rewards green (which humans have the highest sensitivity to) and punishes blue and red (which humans have the least sensitivity to).  Plants are inverted, with the greatest response to red and blue.  The best scale to use for describing light output useful to plants is PAR (photosynthetically active radiation), but very few bulbs give PAR ratings.  The ultimate scale of energy efficiency for bulbs for growing plants is "PAR / Watts".  You could also get a good idea of the efficiency of a bulb by its EQE and then adjust that by its spectrum (EQE = external quantum efficiency: how much energy in equals how much light energy out - no "lumens" correction).  But again, don't expect to see EQE ratings on random lightbulbs.


PAR is the best measure by far! 

Oh, thanks KarenRei "Yeah, I'm cultivating plants in southern Iceland. No, I'm not crazy. Well, maybe ...", for sure you are crazy :) , now I know why you have such knowledge about indoors growing.

Those of us growing indoors or in greenhouses are all a bit crazy...  But I just enjoyed a tree-ripened carambola and guava for breakfast this morning, which isn't possible otherwise in my location.

So, by what you've said, I understand that I am using less than half the luminosity needed per square meter, yes? I'm using 65w FL when needed 150 w FL, right?

Growing more than anything Myrtaceae, will they be ok with light 24/7?

For fluorescent lights, about 400W per square meter is what I would normally recommend for small seedlings.  As they get taller you'll need more light (and probably a different type of light) to get enough light to the lower leaves.

My LED setup is running at about 266W per square meter and is growing and fruiting happy plants up to 1.7 meters tall (I also have a light mover though), but the LED company I now work for actually recommends about 700W of their LED lights per square meter to maximize plant yields.  The general recommendation for HID lights is 1000W per square meter for the equivalent maximum amount of light.

   Kevin

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #10 on: May 28, 2013, 09:57:13 PM »
Thanks Kevin

So, now I'm understanding and clear seeing, You propose something for my cold and dark laundry: "do not spend on an electric stove that consumes 800w, better put lights equivalent to 800w and you'll not only have excellent light but also heat"

Is that correct?

KarenRei

  • Arctic Member
  • Hero Member
  • *****
  • Posts: 1806
    • Reykjavk, Iceland
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #11 on: May 29, 2013, 09:05:38 AM »
Aaaabsolutely.  :)

The cheapest way to get 800W of light/heat, BTW, would be to pick up a high power HID (HPS or MH) system or two.  It should run you maybe $100-150, if I remember US prices right.  I mean, you could get that much light/heat with fluorescent, but you'd be spending a lot more on fixtures.   I mean, in the long run, LEDs would save you money due to the reduced power bill, but for your needs, and given that you need the heat anyway, pure HID should be fine.
J, g er a rkta surnar plntur slandi. Nei, g er ekki klikku. Jja, kannski...

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #12 on: May 29, 2013, 12:14:01 PM »
Aaaabsolutely.  :)

The cheapest way to get 800W of light/heat, BTW, would be to pick up a high power HID (HPS or MH) system or two.  It should run you maybe $100-150, if I remember US prices right.  I mean, you could get that much light/heat with fluorescent, but you'd be spending a lot more on fixtures.   I mean, in the long run, LEDs would save you money due to the reduced power bill, but for your needs, and given that you need the heat anyway, pure HID should be fine.


Ok, thanks, but I dont see clear what is a pure HID

something like this?

http://articulo.mercadolibre.com.ar/MLA-455605747-led-high-power-30w-blanco-frio-_JM#questionText

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #13 on: May 29, 2013, 01:37:12 PM »
Aaaabsolutely.  :)

The cheapest way to get 800W of light/heat, BTW, would be to pick up a high power HID (HPS or MH) system or two.  It should run you maybe $100-150, if I remember US prices right.  I mean, you could get that much light/heat with fluorescent, but you'd be spending a lot more on fixtures.   I mean, in the long run, LEDs would save you money due to the reduced power bill, but for your needs, and given that you need the heat anyway, pure HID should be fine.


Ok, thanks, but I dont see clear what is a pure HID

something like this?

http://articulo.mercadolibre.com.ar/MLA-455605747-led-high-power-30w-blanco-frio-_JM#questionText

That's still LED lighting; the HID lights Karen was referring to look like this:

http://www.hydrofarm.com/catalog.php?category=16

These bulbs get VERY hot (they will start a fire if you let them touch anything flammable) and are relatively cheap for the light you get out of them.  They require a ballast and a reflector to run.

Here's a picture of two HID lights and 4 LED lights in my basement (before I switched to only LED):



The HID lights are in the white reflectors in the middle; the LED lights are in the black housings.  Each of the lights in this picture draws 450W; the HID lights were 400W ceramic metal halide bulbs, and the LEDs each have 180 5W LEDs (16 different colors).  The plants grew so much better under the LED lights that I switched entirely to LED lights:



By the way, a 30W LED light will only cover a small area (maybe 10-20cm square) to grow a few small seedlings; you would need a lot of 30W LED lights to just cover a standard seedling tray.

LED lights still put out heat (they just don't aim it down at the plants like HID / fluorescent lights do); I wouldn't get HID lights just because they are better at putting out heat.  But the HID lights are much cheaper initially; it will take about 2 years of bulb replacement costs and electricity costs before the LED lights are cost - competitive with HID lights or fluorescent lights.

   Kevin






KarenRei

  • Arctic Member
  • Hero Member
  • *****
  • Posts: 1806
    • Reykjavk, Iceland
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #14 on: May 29, 2013, 02:12:14 PM »
CoPlantNut: Full LED, eh?  Neat!  I hope you keep posted on how that goes.  The last time I tried full LED some of my plants were not very happy (most loved it), but there's always the possibility of "experimental error"  :)

Huertasurbanas: HID means "high intensity discharge" and is the general term for a whole family of light types, most prominently (in terms of plant growing at least) HPS (high pressure sodium) and MH (metal halide).  They all work in roughly the same way: a ballast ignites a plasma arc with a surge of high voltage current.  Voltage then drops as the electricity flows through the plasma.  The plasma is formed of the gasses in the tube, which vary depending on the type of HID, and it fluoresces brightly.

Basically, it's a way to produce a ton of light from a rather small fixture.  ;)  I
« Last Edit: May 29, 2013, 02:15:39 PM by KarenRei »
J, g er a rkta surnar plntur slandi. Nei, g er ekki klikku. Jja, kannski...

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #15 on: May 29, 2013, 05:34:14 PM »
CoPlantNut: Full LED, eh?  Neat!  I hope you keep posted on how that goes.  The last time I tried full LED some of my plants were not very happy (most loved it), but there's always the possibility of "experimental error"  :)

Yes, I had tried other LED lights before and had issues with some plants not liking it just as you have; I think there weren't enough different spectra to make all plants happy...  But not all LED lights are the same.  I've been growing ~400 different kinds of plants for 6 months now under nothing but Black Dog LED lights with 16 spectra and everything is happy except dragonfruit, but they weren't happy under fluorescent or 3 different kinds of HID light either.  Many things have started fruiting that hadn't fruited for me before, even under full natural sunlight.  After 20+ years of growing under lights, I'm so impressed with these particular lights that I recently joined the company, so I may be a little biased now- but if you need better LED lights, let me know!

One interesting observation I've had so far is that plants that wintered in my basement under the LEDs didn't have to be shaded when moving them out to full sun; I didn't have any scorching on the leaves like I have always had with HID or fluorescent lights.  I still had to harden the plants off to acclimate them to low humidity, bigger temperature swings and wind though.

I don't miss hitting my head on the very hot HID light reflectors and burning myself, but the LED lights weigh more so I get bruises instead when I hit my head on them.  :)

As far as HID lights go, my favorite (and the cheapest bulbs, at least in my area) were the CMH (ceramic metal halide) bulbs; they have a better color rendering and seemed to make plants happier than MH or HPS.  A whole brand-new CMH setup is about 1/4 the cost of an equivalent-wattage LED light, but the LEDs put out a lot more light and a lot less heat.

   Kevin

huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #16 on: May 29, 2013, 06:18:13 PM »
Well, now I'm starting to speak the same language that you.

I went to a dealer in electrical and lighting, he had several options for me.

Here in Argentina we call them reflectors popularly what you call HID lights, and are used in soccer and to illuminate large outdoor spaces.

They can sell:

500 w incandescent reflector, USD 22.5
Sopotsline Reflector MH 400 w USD 130
Sopotsline Reflector FL 105 W USD 68

The 500w is very cheap, is the most common but yellow light bulb, do not think you like it ... Furthermore, vendor told me the 400w MH lights much more than common 500w, would that be true? how many more?

The FL does not suit me because I need to raise temperature.


(By the way, on the net i could find interesting led lights, for instance, this
http://articulo.mercadolibre.com.ar/MLA-456416102-reflector-led-100w-industria-argentinaip-65-apto-intemperie-_JM#questionText

100w led would be like twice a 500 w MH HIDw?)
« Last Edit: May 29, 2013, 06:34:18 PM by huertasurbanas »

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #17 on: May 29, 2013, 08:29:48 PM »
The 500w is very cheap, is the most common but yellow light bulb, do not think you like it ... Furthermore, vendor told me the 400w MH lights much more than common 500w, would that be true? how many more?

The 500W incandescent reflector is very cheap because it is an incandescent bulb (not what we're calling HID).  Incandescent lights aren't good for plant growth- they put off too much heat and generally too little light-- though a 500W bulb should put off a lot of light, you'll have to keep the plants too far away from it because of the heat.

The 400W MH would be good (and is an HID light-- "MH", "HPS" and "CMH" lights are all HID); they are much more common here in the US than the 500W incandescent bulbs.

The FL does not suit me because I need to raise temperature.

If you put 4 of those 105W fluorescent lights in a room, they'll raise the temperature about as much as the 400W MH light would.  The lights are all going to create heat; even the light they produce will get turned into heat when it is absorbed by the walls and even the plants (though a small amount of light is converted to sugars in the plants rather than just heat).  Basically, any light-- fluorescent, HID, LED, incandescent-- will warm the room about as much as an electric heater of the same wattage.  There are slight differences, but not enough to consider.

For example, the 450W LED lights I use put out almost as much heat as a 400W CMH light (with ballast, which takes another 50 watts), so they warm a room about the same.  The difference is the CMH (all HID lights) direct most of the heat down at the plants, where the LED lights the heat is mostly lost from the top of the light and away from the plants in the LED's heat sink (the metal flanges above the LEDs).

(By the way, on the net i could find interesting led lights, for instance, this
http://articulo.mercadolibre.com.ar/MLA-456416102-reflector-led-100w-industria-argentinaip-65-apto-intemperie-_JM#questionText

100w led would be like twice a 500 w MH HIDw?)

That LED light looks like it puts out white light, correct?  (My Spanish is not the best).  One of the ways LED lights can be more efficient for growing plants is by only producing light the plants will use.  White LED lights will grow plants, but they are wasting energy creating wavelengths of light the plants won't use.  Plants mostly use light in the red and blue area of the spectrum; that is why the LED lights in my photos above look purple (because they are mostly red and blue LEDs) and the plant leaves under them look almost black-- the plants are absorbing most all of the light the LEDs put out.

A 100W white LED may be equivalent to a 500W incandescent light bulb for illuminating a room, but for growing plants neither is ideal.  The LED lights specifically made for growing plants (mostly red and blue light) are where you really start to get the best efficiency of plant growth per watt used, because they only produce light the plants can actually use.

   Kevin


huertasurbanas

  • Hero Member
  • *****
  • Posts: 2803
    • Junn, Argentina, zone 9b/9a
    • View Profile
    • huertasurbanas
Re: tropical / subtropical seedlings and lighting
« Reply #18 on: May 30, 2013, 12:01:07 AM »
TOO GOOD!

I translated it:

http://www.huertasurbanas.com/2013/05/30/lamparas-para-cultivar-plantas-en-interiores/

now I should get some blue and red leds some day...

Hey, tell me,

what fruit trees (did) you managed to fruit there?

how many months per year growing inside?

I'm not planning to make fruitful trees in the laundry room, just grow seedlings for the 5  months of frosts and then take them out in the spring-summer-fall again.
« Last Edit: May 30, 2013, 10:35:43 AM by huertasurbanas »

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #19 on: May 30, 2013, 03:02:46 AM »
now I should get some blue and red leds some day...

In my experience, blue and red LEDs aren't enough; you need a few more spectra to keep a lot of plants happy.  The precise "shade" (wavelength) of blue and red and other colors matter, as LED lights are very narrow-spectrum unless combined or with added phosphors.  Lettuce will grow happily under only red light, but for most other plants other colors seem to be required for proper growth and flowering.

Hey, tell me,

what fruit trees do you managed to fruit there?

how many months per year growing inside?

I typically have 7-8 months of indoor growing and 4-5 months of outdoor growing time available for tropical plants in Colorado.  Due to our low humidity and high winds, some plants do better indoors all year.

I've fruited various citrus, figs, guavas (strawberry guava is still my favorite), Chilean Guava (Ugni molinae), miracle fruit, mulberries, Barbados Cherry...  I've tried and failed many years in a row with Naranjilla and too many others to list.  But since switching to LED lights I've had much more luck fruiting all sorts of plants indoors over the winter, such as dwarf guava:

Eugenia reinwardtiana:

Miracle fruit:

Carambola (in a 5-gallon pot):
(earlier but same fruit as #1:)

I've got many long-term projects; my mangosteens still have a long way to grow before they'll fruit:

but I've added 2 different species (G. xanthochymus and G. hombroniana) as rootstocks to each in an attempt to speed things up.

I'm not planning to make fruitful trees in the laundry room, just grow seedlings for the 5  months of frosts and then take them out in the spring-summer-fall again.

If you're only planning on growing for 1 year in your laundry room before moving your plants into a greenhouse for the winter, I would buy fluorescent lights.  If 2-3 years I would probably suggest HID lights (CMH, MH or HPS).  If you're looking for 3 or more years use out of indoor grow lights for anything more than starting seedlings I would suggest LEDs specifically designed to grow plants.  For most of these LED plant lights (as Karen has said) you'll still need another form of supplemental light to make your plants happy, but the pictures above show how happy my plants are under only LEDs if you get the right spectrum and intensity.
 
   Kevin
« Last Edit: May 30, 2013, 03:06:44 AM by CoPlantNut »

carraig

  • Member
  • ***
  • Posts: 80
    • View Profile
    • Amber's Edibles
Re: tropical / subtropical seedlings and lighting
« Reply #20 on: May 30, 2013, 01:48:05 PM »
Yes, I had tried other LED lights before and had issues with some plants not liking it just as you have; I think there weren't enough different spectra to make all plants happy...  But not all LED lights are the same.  I've been growing ~400 different kinds of plants for 6 months now under nothing but Black Dog LED lights with 16 spectra and everything is happy except dragonfruit, but they weren't happy under fluorescent or 3 different kinds of HID light either.  Many things have started fruiting that hadn't fruited for me before, even under full natural sunlight.  After 20+ years of growing under lights, I'm so impressed with these particular lights that I recently joined the company, so I may be a little biased now- but if you need better LED lights, let me know!

You spent $1200+/light?  That's CRAZY!  $1200 per 9sq ft is incomprehensible to me unless one is growing drugs and making drug-style money. (not saying you are, just saying that the cost of these lights is nuts.)

CoPlantNut

  • Hero Member
  • *****
  • Posts: 551
    • USA, Longmont, Colorado: Zone 5
    • View Profile
Re: tropical / subtropical seedlings and lighting
« Reply #21 on: May 30, 2013, 03:52:22 PM »
You spent $1200+/light?  That's CRAZY!  $1200 per 9sq ft is incomprehensible to me unless one is growing drugs and making drug-style money. (not saying you are, just saying that the cost of these lights is nuts.)

Yes, I'm nuts; there is no way my fruit is cost-effective; I would have to grow a different crop if I were looking to make money through my indoor growing...  But if you consider just the cost of bulb replacement for MH / HPS lights, these LED lights will pay for themselves in 5-6 years.  When the lower electric bill is factored in (both for lights and cooling costs) the LED lights pay for themselves compared to HID lights in about 2-3 years.

    Kevin

 

SMF spam blocked by CleanTalk