Night lighting and its affect on cacti

[tumamoc]

OK-I've been driving past this poor spotlighted saguaro every morning on the way to work and it makes me wonder how much of an impact nighttime lighting has on cacti. This is an extreme case, but are we negatively affecting cacti when we keep them on a constantly lit porch?

saguaro spotlight.jpg (33.84 KiB) Viewed 495 times

[gemhunter178]

Hmm....interesting.....

[iann]

Not just light:
http://rspb.royalsocietypublishing.org/ ... .2012.0230

I think you'd need pretty bright light to have an effect though. Brighter than a full moon, for example. That's not even a regular street light, is it? The cactus probably blocking a good proportion of that spotlight.

[tumamoc]

Hmmm. On second thought, it's probably this power pole that's causing this saguaro to lean .

0817121131.jpg (28.7 KiB) Viewed 396 times

[majcka]

Hmmm. On second thought, it's probably this power pole that's causing this saguaro to lean .

0817121131.jpg

Somehow I don't believe that. Because the wires are all over and it wouldn't know where to lean and just the bar doesn't cause it, right?

[Saxicola]

I doubt light is making it lean, but depending on the plant even low levels of light can have an effect. The most dramatic I know about is Poinsettias. Growers cover their greenhouses in curtains at night because a street light or even car headlights for just 10 minutes can disrupt flowering.

[Peterthecactusguy]

yes to make a poinsettia "bloom" it has to be in the dark for awhile. as for cacti, I dunno, I never really though much about it but I have some that stay on my porch with my light on all the time.

[Steve Johnson]

I doubt light is making it lean, but depending on the plant even low levels of light can have an effect. The most dramatic I know about is Poinsettias. Growers cover their greenhouses in curtains at night because a street light or even car headlights for just 10 minutes can disrupt flowering.

Okay, here's an interesting question -- and not merely academic either. Today the street department installed a sodium vapor light on the pole right in back of where my plant bench sits. It's the sickly orange barf-glow kind. Didn't expect to see it, but I saw the bloody thing lit up tonight. Does anyone know if this will have any adverse effects on my cacti? Nothing I can do about the situation, but I'm hoping the light spectrum being generated isn't going to interfere with how they'd normally behave at night.

[Saxicola]

I highly doubt it will make any difference. I mentioned the Poinsettia thing because it is so unusual for a plant to be so strongly affected by ambient light as that plant. Even then, it doesn't affect the growth, it just goofs up the flowering a bit. Poinsettias are a major crop and production is amazingly well organized and timed, to the point where they know the exact day the plants will be ready for shipping based on the day they plant the cuttings months before.

Most plants aren't so touchy and most won't be affected at all. At worst if may throw off flowering a little bit... maybe.

That being said, it would be interesting to see if succulent Euphorbias had their flowering affected since Poinsettias are Euphorbia pulcherrima.

[Steve Johnson]

I highly doubt it will make any difference. I mentioned the Poinsettia thing because it is so unusual for a plant to be so strongly affected by ambient light as that plant. Even then, it doesn't affect the growth, it just goofs up the flowering a bit. Poinsettias are a major crop and production is amazingly well organized and timed, to the point where they know the exact day the plants will be ready for shipping based on the day they plant the cuttings months before.

Most plants aren't so touchy and most won't be affected at all. At worst if may throw off flowering a little bit... maybe.

That being said, it would be interesting to see if succulent Euphorbias had their flowering affected since Poinsettias are Euphorbia pulcherrima.

Good news then. Now, if I had any night-blooming cacti, I'd be pretty ticked off. Luckily not a problem, although I'd be interested to know if any other members on the forum do run into it on their night-bloomers.

Thanks!

[Steve Johnson]

For the sake of being thorough, here's a time-exposure photo of my plant bench under the sodium vapor light. Hopefully this should give you an adequate idea of the light intensity we're dealing with:

Sodium_vapor_light09182012.JPG (108.08 KiB) Viewed 244 times

Any second opinions on whether or not the "barf-glow" light would have any effect on the normal growth of my cacti?

Thanks!