I find that lights attract bugs and moths that lay eggs and their caterpillers hatch and eat the plant. And lights also repel certain animals like deer I have heard....but I don't think it will affect your plants in an y negative way as it would with something like poinsettia.

Where am located I don't believe in security lights, they only draw attention to my place. It is not possible to see my house from the road, so why tell anyone "hey, I am here!"

Ditto what Lilo says. Actually security lights have really not been ever proven to enhance security. They allow shadows where bad elements can hide, and they also show off what you don't want messed with.

Whether light affects your plants or not just really depends on the plant. No plant ever evolved around light 24/7. Many plants are photoperiodic for bloom you'd never suspect. Stuff like marigold, fuschia. Light also affects things other than bloom signal. Sometimes the light has to be over a certain threshold.

If you really are convinced light is needed for security, the best of both worlds is to slave it to a motion sensor. That way it's there only when there is activity in the area.

I would not worry about the security lights in your garden for the plants, unless they are grow lights or full spectrum lights and I don't know of any security lights that are full spectrum.

Security lights are able to mess up even garden mums. It doesn't have to be in the spectrum needed for growth or proper photosynthesis, just sufficient candlepower and for something strongly photoperiodic it can be as low as ten footcandles. When I was retarding bloom in poinsettia crops, or increasing bud count in things like Easter lilies, I used large banks of (you guessed it) 5K watt security lights. I really doubt things like beans and vetch or rye is a big concern unless your garden is lit up like a football field and maybe not even then.

Thanks for the responses. I know some plants are real sensitive to the day/night cycle and the smallest bit of light can screw em up, especially during flowering. These lights arent even real security lights, just 100 watt bulbs around the house. Kinda like a porchlight, but around the windows and things like that.

As for security concerns, I understand both sides of this. I live on a block of one acre lots, seven houses on the block. Empty behind, empty in front, empty all around. I used to just keep the porch light on. Bout a year ago my car got broken into, in my drive way, at night, while I was home. ya I know, park car in garage. Put alarm on car. But that being said, every other house on my block has the lights on at night, and If I didnt I think it would look either suspicious or like noones home.