Light pollution - street lighting affecting photoperiod

Xenie

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I have noticed that the buds one of my mugo pines (p. mugo “mini mini”) are slightly beginning to push candles. It’s only February, and none of my other conifers are pushing yet. A super bright LED street light had been installed and is throwing light on my balcony where the mugo resides. I am wondering if this could be affecting the photoperiod of my mugo, resulting in elongated buds. Since the phenomena seems to be isolated to this particular specimen, could it be that there is variation in sensitivity to light within my plant collection? Or, is it something else all together? The affected mugo is a miniature, with a growth rate of .5”/yr. Has anyone had experience with night light pollution affecting their plants?

Also, I have noticed that many, if not all of the Monterey Pines around town are producing pollen cones like crazy. Are pollen cones a precursor to candles? Or do they accompany candles?
 

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Wires_Guy_wires

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I found street lights to not interfere with (very) photosensitive plants like cannabis, given that the light is always there.
 

It's Kev

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My city lights up like it’s Christmas every single day, my trees seem to be fine. Put your location in your profile so we can get an estimate about your climate. I’m in zone 10 so it seriously doesn’t matter when my trees break dormancy because they won’t freeze. Your situation might be different
 

Wires_Guy_wires

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I wonder... Could you make a cannabis plant into a bonsai?
Yes, but it would ruin the plant. After about 4 years, the genetic deterioration takes real visual effect. The older they get, the more difficult they become.
I lost a 5 year old specimen due to wood lice, after that I gave up on trying.
 

Xenie

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My city lights up like it’s Christmas every single day, my trees seem to be fine. Put your location in your profile so we can get an estimate about your climate. I’m in zone 10 so it seriously doesn’t matter when my trees break dormancy because they won’t freeze. Your situation might be different
Sorry, zone 10B.
Good to know about the street lights. Do you know about pollen cones? Do they generally come before candels elongate, or along with candles? I’m trying to figure out a timeline for conifer activity. I know female comes form in the fall, and new buds form in late summer.
 

Vance Wood

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Yes, but it would ruin the plant. After about 4 years, the genetic deterioration takes real visual effect. The older they get, the more difficult they become.
I lost a 5 year old specimen due to wood lice, after that I gave up on trying.
Just invite people over and cremate the remains of the plant with your friends and fellow bonsai heads. Lots of munchies and good things to drink for the wake.
 

It's Kev

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Sorry, zone 10B.
Good to know about the street lights. Do you know about pollen cones? Do they generally come before candels elongate, or along with candles? I’m trying to figure out a timeline for conifer activity. I know female comes form in the fall, and new buds form in late summer.
My first year getting serious into conifers, so I don’t know. Since you’re also zone 10, don’t worry about bud break, my winter was unusually warm and chances for frost are minimal, let them grow
 

ysrgrathe

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According to Dirr a single 100W incandescent is all that is needed to extend photoperiod to produce growth in cuttings, so it seems possible that there could be an effect. This was in reference to deciduous cuttings though, not conifers.
 

Wires_Guy_wires

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According to Dirr a single 100W incandescent is all that is needed to extend photoperiod to produce growth in cuttings, so it seems possible that there could be an effect. This was in reference to deciduous cuttings though, not conifers.
Take into account that this light was meant to function like that. It was most likely placed at a short distance from the canopy. With a street light, which are usually 4 meters tall, that effect is diminished.
I've been growing photosensitive plants for over a decade now, and they don't care about street lights. If I were to lower those street lights by half their height, those photosensitive plants would indeed not flower at all.

Fun fact: with the rise of LED's, more and more European countries are switching to green street lights. Not energy-friendly, but green in color. That color doesn't attract bugs and it doesn't affect plants as much as white and orange lights do.
If street lights do prove to hurt your plants, then just put a green piece of plastic over them. As with most plant-related ingenuities, this type of green LED is commonly used and widely accepted in the cannabis world. The green light doesn't mess up the dark period, which allows people to work when those super hot and bright lights are out. Greenhouses are implementing them too, but only at a very modest pace.
 

rockm

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I have noticed that the buds one of my mugo pines (p. mugo “mini mini”) are slightly beginning to push candles. It’s only February, and none of my other conifers are pushing yet. A super bright LED street light had been installed and is throwing light on my balcony where the mugo resides. I am wondering if this could be affecting the photoperiod of my mugo, resulting in elongated buds. Since the phenomena seems to be isolated to this particular specimen, could it be that there is variation in sensitivity to light within my plant collection? Or, is it something else all together? The affected mugo is a miniature, with a growth rate of .5”/yr. Has anyone had experience with night light pollution affecting their plants?

Also, I have noticed that many, if not all of the Monterey Pines around town are producing pollen cones like crazy. Are pollen cones a precursor to candles? Or do they accompany candles?

Any chance the surrounding air around the balcony has been warmer on average than that closer to the ground? The ground temperature can lag behind air temps. The balcony may be warmer relative to the plants in the backyard..
 

0soyoung

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A mugo in zone 10?

Though out of context, Vance's words likely apply
Just invite people over and cremate the remains of the plant with your friends and fellow bonsai heads. Lots of munchies and good things to drink for the wake.
 

Leo in N E Illinois

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@Xenie

Photoperiod is NOT the problem. Being in a sub-tropical climate is the problem. Mugo is a high elevation temperate zone mountain pine. Your poor pine is probably confused by the lack of cold.

One a few species of trees strongly rely on photoperiod. Most use temperature and other cues to determine dormancy. The Euphorbia family does have photoperiod sensitive members, example; Poinsettia.

There are trees that use a combination of cues to determine growing season. But across the board temperature is the most common, therefore major, driver of seasonal response.
 

Xenie

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@Xenie

Photoperiod is NOT the problem. Being in a sub-tropical climate is the problem. Mugo is a high elevation temperate zone mountain pine. Your poor pine is probably confused by the lack of cold.

One a few species of trees strongly rely on photoperiod. Most use temperature and other cues to determine dormancy. The Euphorbia family does have photoperiod sensitive members, example; Poinsettia.

There are trees that use a combination of cues to determine growing season. But across the board temperature is the most common, therefore major, driver of seasonal response.

Thanks for the reply Leo. We have a ton of conifers here in the Bay Area. The San Francisco Botanical Garden is a reference garden for the American Conifer Society. I have been a bit concerned about lack of actual chill hours, since I am right on the coast and hours below 45 are <400. But we get plenty of hours between 50 and 45. The conifers here seem to make due, and even thrive, despite true harsh winter. Just down the coast in Halfmoon Bay you can find a ton of Christmas tree farms growing Noble Firs to Norway Spruce and everything in between. I think our biggest benefit is the cold/wet and foggy summer months. I have actually been throwing some of my plants into a mini fridge overnight. This probably is not necessary, but it helps me sleep at night.

The whole zone thing is kinda silly I think. If you go on USDA zone alone, San Francisco and San Diego would appear to have the same climate!

Any how, thanks for all the replies. I think I am going to remain suspicious of this damn street light. Sure would hate to accidentally pull the trigger on my BB gun while aimed at it...
 

Leo in N E Illinois

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I hate street lights too, but the reason has nothing to do with bonsai. ?

Sounds good. I know many conifers thrive in the SF area, but not all species will thrive there. Chill requirements are species specific, some need more than others. The generalization of hours below 40 F or 4 C is just a useful guess, each species has it's own number of hours at various temps. So I'm just stabbing in the dark as to the reason your mugo is not responding well. We both could be barking up the wrong tree.
 

Xenie

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I hate street lights too, but the reason has nothing to do with bonsai. ?

Sounds good. I know many conifers thrive in the SF area, but not all species will thrive there. Chill requirements are species specific, some need more than others. The generalization of hours below 40 F or 4 C is just a useful guess, each species has it's own number of hours at various temps. So I'm just stabbing in the dark as to the reason your mugo is not responding well. We both could be barking up the wrong tree.

Thanks, Leo. A Christmas tree farmer I talked to said Norway Spruce will grow and look beautiful, but it takes 13 years to get one to a harvestable size.

I’m wondering how scientists are genetically modifying fruit trees to deal with chill hours. Apparently, there are now apples that will fruit in the south because of this work. Some estimates are saying that California’s Central Valley will no longer be able to produce many of the crops it does currently because of climate change and decreasing chill hours. I say good riddance. That valley should never have become the unsustainable agricultural power house it is. We have built dams and diverted water into a desert with good soil. They grow water intensive crops like almonds and pomegranates because they generate the highest revenue per acre. Then we ship it all to Asia. When you drive threw you see signs that say “is growing food wasting water?” Ah, sorry for the rant.

Any how, I’m wondering, if fruit trees can be modified to produce in warmer climates, maybe conifers can to.
 

Leo in N E Illinois

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Actually much of the reduction in the chill hours required for apples has been good old fashioned conventional breeding. The GMO work has been for apples that don't brown after you cut them up. GMO Apples that stay crisp in storage for near one year,.and other freaking things.
 

Hyn Patty

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My mugo is starting pushing candles as well and I assure you that it's still cold up here on our mountain top and there is NO light at all after dark except the stars and moon. It may have more to do with warmth and rain.
 
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