Urban light pollution. How much is too much for outdoor flowering?

Outdoor Growing
#1

Hello. I’m planning my first little photoperiod outdoor run. So far my biggest concern was getting plants done > 50°N. Now I think I have another, maybe bigger problem. Living in a city, it is never really dark.

In my case there will be some light shining up to my place, I should be able to block the direct light. And there will be light from my neighbour’s window. Which was pretty annoying last winter, never noticed before. I am not sure if I can block all of that.

What are your experiences with light pollution in outdoor grows? What worked, what didn’t?

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#2

My neighbor’s plant wouldn’t bloom in late fall. He finally realized that the street light in his backyard was the problem. He shut the light off and the plant went into bloom

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#3

I have very bad outdoor light pollution.

The only solution I have is autos or semis.

I live across the street from an ikea parking lot which might give you some idea of how bright.

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#4

As long as you block any intense direct light you should be good.
My neighbor had a bright LED flood light shining towards my yard all night that may have caused some herm issues a couple years ago.
I put up a little barrier to block it last season and had no problems.

Other than that, haven’t had any issues in 5 seasons growing in the ‘burbs with street lights, porch lights, etc. (no parking lots nearby, though)

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#5

Ouch. On the other hand, free grow light for the autos.

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#6

Yeah. The balcony gets near perfect sun it’s such a waste.

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#7

I grow outdoors and my small apartment building has all-night security lights. There is, however, one small area that, while lighted by a street light, is blocked from most of the building’s lights. I block the light as much as possible with a piece of plywood (actually OSB) leaning against that handtruck. I take it down every morning. It’s not dark dark like it might by in a rural setting with no barnyard or night lights, but the plants seem to think it’s dark enough.

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#8

Cool idea @mota!

Why do you have to take it down every morning?

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#9

You pimp you, just pimping them sweethearts in the dark corner.

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#10

Strictly for convenience when I’m moving 10 gallon pots. I don’t really have to take it down. This may sound silly, but every little bit of exercise I can manage is good for my old ass.

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#11

Damn right! Don’t want the whole neighborhood sniffin’ around the hen house. :wink:

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#12

Yeah, I’d say autos. Good call @Foreigner.

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#13

That gives me some hope, thanks.

That’s cool. Also reading that you carry around your plants several times a day. Wow. I use black fabric on one side for privacy and consider using it on the other to block some of the light but thought putting it up and taking it down every day would be a pita. Yes, I’m lazy and forgetful.

Well my point in asking the question was that I want to run photoperiod strains. I have autos and semiautos going now but growing some of the photos under the sun would be really great. If it fails I won’t have another option but I’d like to find out if it’s worth trying at all. So far I’m rather encouraged by the experiences shared. Thanks for that and happy to read more of them, good or bad.

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#14

Yup, I’m an ass.
Don’t mind me!
:laughing:

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#15

It’s alright :joy:

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#16

As long as you’re under 10 nmols you’ll be fine for most strains.

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#17

Thank you, that was interesting. I’m mildly confused by 20°C being a “cool night” because my cool nights will be around 0°C and that will apparently have an impact if the relations he uses in this part are accurate.

A tropical night is a term used in many European countries to describe days when the temperature does not fall below 20 °C (68.0 °F) during the nighttime

:crazy_face:

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#18

10 years ago or so I had the same problem and used heavy duty tarp to shield the plants from the light. I had a couple lines(clothesline) over head I ran. It went along side the grow area, and I fixed the tarp over it, and it dropped down the sides of the plants completely covering them. It was really loose so it still allowed airflow.

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#19

Move to the country, eat a lot of peaches.

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#20

That’s what I did. Never going back either lol.
BTW that method can be used to flower an outdoor plant early, although a material that allows some airflow is best, like a shade cloth that reduces light 90 to 100 percent. Depending on how many you are growing, leave them on a cart and just roll them into your makeshift dark area when time. It does work, and as many know, if you lower their time out in the sun to 10, 11 hours, the really long flowering sativas will finish sooner…

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