I've wanted to make some lighting for my ferns and have been reading around looking for a simple solution. So far I've purchased one of the Philips warm white LED bulbs, 9.5W 800 lumens 2700K

Now I came to this conclusion from reading around and particularly this article. https://today.duke.edu/2014/04...

If I understand everything correctly then these ferns would do well with the light spectrum closer to the red side, hence the 2700K bulb.

What I'm not sure of is if this bulb is actually effective since the LEDs are behind a cover.

I'm basically trying to ensure my ferns get sufficient light everyday regardless of weather conditions because where I live the indirect light needed isn't always available.

Any suggestions?

Hi @roose Welcome to ATP I think the folks tagged below should be able to help you.

@RickCorey has a pretty good handle on lighting. Same for @Leftwood and @plantladylin Lin has ferns indoors and may be able to advise you also.

This is a link to the Fern Forumfor general info and additional help.
http://garden.org/forums/view/...

Hi, Roose. Welcome to ATP!

I have to admit that I don't know ferns. Is 800 lumens enough for them? It might depend on how close the bulb is, and over how much area the light spreads. I'm guessing that since many ferns are happy in shade, they might not need very bright light.

And a "spotlight" focuses the light better than linear shop lights do.

I'm used to fixtures with two 48" bulbs spreading maybe 5,000 lumens over 8-10 square feet, say 500 lumens per square foot. If ferns need that same brightness, 800 lumens would only cover 1.6 square feet.

... That article from Duke said they've evolved to handle low light levels, but HOW low? I couldn't find an answer online. Maybe the light you already had in that spot before adding the 800 lumen LED bulb, plus the bulb, will be enough.

If you put a book with small print where the ferns are going, and the light is enough to read easily, I'm guessing that's enough for a "part shade" plant. But hopefully someone with more of a clue will come along.

:welcome:@roose.

@rickcorey is exactly right concerning what 800 lumens actually represent. It is important to know what the lumens are that the fern(s) is actually getting. Other than staghorn and elkhorn ferns, I personally don't grow the kind of ferns that you are probably referring to. The fluorescent lighting I use is only to supplement light during the late fall and winter months. My fluorescent fixtures produce so many lumens I have to actually get those fixtures a good ways away from my plants. Each fixture produces approximately 30,000 lumens right at the tubes. Two feet away, and those lumens are about cut in half but that 15,000 lumens covers an area of 4x6'.

All I can tell you is to try to put your fixture as close to your fern(s) as possible. Those low-lumen LED's produce almost no heat. The downside is that the closer the LED are to the plants, the less coverage there will be. It becomes a trade-off unless you have multiple LED fixtures. If the LED is pretty much your sole source of light, I would burn that LED 12-16 hrs. a day.

Hi roose, Welcome to All Things Plants from me too! I wish I could offer suggestions and tips but I don't grow ferns indoors; mine are all out on the screened porch and I have no knowledge of lights. Hopefully someone will be along soon to be able to help.

@plantladylin sorry, I misread your thread on the fern forum. I thought you had indoor ferns in addition to container plants on the porch.

@Moonhowl ... I probably have had a fern or two indoors at some point over the years but ferns don't remain indoors for long because I've never had luck keeping them alive so they end up on the screened porch.

Hello, Roose, and season's greetings.

500 lumens per square foot ought to be enough to satisfy them, but double that would not be too much and would be more productive. In terms of usable light, your sunniest window inside the house is roughly equivalent to open shade outside. Unfortunately, that doesn't always mean you should put a plant that grows in shade outside in your sunniest window. There are other factors involving plant health that may preclude such a decision.

That's an interesting article you found. What it says is that ferns adapted to use more of the red light than they had previously. That doesn't mean they use light in the blue spectrum any less. It's still good to have both red and blue light available for your ferns, but is it necessary? I don't know. It's likely they will do fine in either light, but will benefit from having both. The major energy producing syntheses in plants use both red and blue light, not just one or the other exclusively. Although they can operate with either red or blue light, greater efficiency comes when both colors are present, and other necessary plant processes are affected as well.

I know I'm making it sound like rocket science, but it need not be. Just get in the ballpark and you'll do fine.

Does anyone know what the first or most obvious symptoms are of not-enough-light in indoor ferns?

It would be helpful to say "Watch out for XYZ, and try giving them more light if you see that".

If the extra light was focused on only some of the plants, and those plants improved while others didn't, then low-light was probably the problem.

I was surprised to read ANYONE advising putting a incandescent bulb over any kind of plant. I saw that in some article I scanned for ferns. Unless they were trying to give them heat as well as reddish light.

Well, maybe the Koch brothers would suggest it, to increase consumption of electricity and coal.

If you need more light, I would add a CFL bulb - a spotlight bulb with built-in reflector, or a regular "pretzel" CFL bulb screwed into a down-aiming reflector on a light pole. Cheap and you can get any brightness you want, up to maybe 1500 lumens. But I bet two 800-lumen bulbs would be cheaper and more efficient than one 1500-lumen bulb.

That article made it sound right that a redder color is better for ferns, hence another "warm white" bulb would be good.

But I also bet that the warm LED bulb you already have gives enough excess red. If you just like a cooler color in your home, get a cooler color. Doubling the brightness has to be better for the plant than fine-tuning the color.

P.S. You were concerned about the light cover? Since the light that supports photosynthesis is in the visible range, and the cover lets visible light through, I doubt it filters out anything that would have helped the plant. If it absorbed infrared, it would get hot and then re-radiate infrared, so even there I don't think a cover hurts much. Just keep it clean.

Thanks Rick R and Rick C for your help.

RickCorey said:Does anyone know what the first or most obvious symptoms are of not-enough-light in indoor ferns?

The normal stuff:
--- weak growth that stretches toward the light
--- lighter colored new fronds
--- massive die-off of fronds shaded by other fronds, ultimately leading to a much thinner plant. Fronds that die-off should turn yellow before brown and dry.

Thanks for the advice all.

LED lighting has come a long way, in the next few years all your fixtures using CFLs will be replaced by LEDs. The price point has come down and the value of a LED light is phenomenal compared to anything else. These things are currently rated to last 22 years and cost about $1 to run for a year for a 60W equivalent.

At first I was going to just get a couple of reds and a blue LED and rig up a simple fixture but then I've learned that affordably priced bulbs are in the hardware stores so that's why I'm on this LED bulb kick.

Got all these ideas about redoing the lighting in my home and maybe getting some more plants in and situate my setting so that the typical rooms light's supplement the houseplants as well as provide general light for living.

This bit about my ferns is perhaps just the starting point since ferns don't need so much light it's not too much of a risk.

Unfortunately, I have not had good results with my high-end, LED fixtures. All the higher wattage ones lasted a year and then one by one, in rapid fashion, quit working. I contacted the seller but never even received an answer as to what to do to get them going again. Of course, they were all made and sold by a Chinese manufacturer. I will stick to high-lumen, T-5HO fixtures for awhile.

If your LED brands are from china then that's a big issue. They don't take care in balancing each diode in series and resistance between each diode can be an issue for the current being driven. This can reduce the life of LED by essentially burning them up. Their drivers probably aren't properly adjusted either. Also the heat can be an issue, if the LED's aren't placed on properly on sufficient heat sinks then as the LEDs get warmer their resistance will decrease and end up drawing more current.

Stay way from china basically

Are there any LED's not made in China now? I have looked extensively for greenhouse-suitable ones (must be waterproof) and there is nothing I have been able to find that is not made in China. Perhaps you can give me a link or direct me to a site(s) where the LED fixture is made in the USA.

@drdawg Hi Ken Merry Christmas

Check out these sites.

https://www.earthled.com/colle...

http://www.ledwaves.com/

http://www.theledlight.com/ass...

Thanks, Jean.

Hello All and happy holidays.

Roose, I think the 2700k bulb will work insofar as the color temp and the additional red spectrum. Any of the "white" type led bulbs will have a mix of the color spectrum from blue to red. It is the proportions that will control whether they are "warm" (red) or "cool" blue. The intensity will probably be too low unless you provide some sort of a reflector though, as the specs you have given appear to be of one of the standard base type lamp bulbs that will not provide any directed light. I do not have any of the spectrum data for the philips 2700k bulbs but believe they will just have more red and a bit less blue than the 3000k that are available in in the linear Tled bulbs. Honestly, I would buy 2700k Tleds for my setup if they were available.

More info below that you or others may find useful.

I have been growing seedling plants under lights for lots of years. I mostly grow lilies that I hybridize, but this past year I grew lots of various annuals and perennials. In prior years all were grown under T12 shoplights with a 4100k color temperature, then eventually over to T8's. For the most part growth was reasonable except for one year when I went to 5000k color temp in an 800 series bulb. I believe the 800 series had a better color rendering index, but this was done with the color phosphors that illuminate the bulb. These 800 series bulbs while making things look better by eye, actually were shifting away from the color spectrum needed by the plants.

I am now growing most of the seedlings under leds. I have a few Philips commercial fixtures (not at all cheap), and a few of the fluorescent fixtures now running Phillips Tled Instant-Fit bulbs. Both work well. The Tleds I have used are 3500k. I will be purchasing a few more of the Tled bulbs but at a 3000k color temperature as I now have data that lead me to believe these will work better.

Above is a plot that I made showing the Philips Tled spectrum data at the wavelengths most important to photosynthesis. The most important part of the spectrum is in the 610 to 660 band (red to far red), and the blue spectrum at 460 to 470 is also important. Six to eight percent of the light requirement is from the blue spectrum region.

Cost difference to set up is 2 to 3 x greater using the Phillips commercial fixtures over the Phillips Tled. Power usage is 3 x 35 watts = 105 watts per shelf using the commercial fixture vs 3 x 44 watts = 132 watts using the Tleds. It will take quite a while to make up for the initial cost of the commercial units. The commercial units do run a bit cooler, although neither is overly warm. I have been able to use a 12 hour on 12 hour off schedule with the leds, where I used to use a 16 hour on cycle with the T8 fluorescent tubes.

The commercial units have a red to blue led ratio of 4 to 1. Probably not optimal as these are mostly designed for growing leaf type crops. I have noticed that not everything liked these lights (I should have made more notes and photos.) The commercial fixtures are difficult to work around as healthy leaves will appear black to very deep purple. It also temporarily makes everything look green when you get under normal light.

+ All in all both led setups work.
+ Led setups can be placed closer to the leaves without burning them.
+ Cheaper Tled setup may work better for some plants but will require some testing.

Verbascum liking the commercial led grow fixtures
Lily seedlings under the commercial fixtures
Various annual seedlings under the Tleds

Hankz

Great info @hankz