I hate motion sensor lights. I keep my outside LED floodlights on from sunset to sunrise using astronomical timers. I suspect the constant light may be killing grass and hedges.

Has anyone else ever run into this?

I worked in a prison with high mast, high intensity lighting. The plants and flowers under the lighted areas grew several times the size of the plants in the dark areas. Used to freak me out, sometimes the light cut across a plant or bush and one side grew large while the other side did not. LED may have different effects.

I'll give you this possible explanation.

Many plants use daylength to regulate their life cycles. Flowering and dormancy for example. Your lights might have effected the dormancy. Rather than being dormant during inclement winter weather they are trying to actively grow.

Soybeans under street lights mature differently than those in the dark part of the field, they don't know it's fall.

Well being LED, they don't put out much UV, but maybe the lights are tricking the plants into expecting a UV meal. Hell, I don't know.

If I recall correctly, many years back trees were dying after the then new sodium vapor lamps used for street lighting were causing an upset in the timing of deciduous trees losing their leaves. The trees were staying in their active summertime life cycle and when the freeze hit it killed the trees. Perhaps the light from your fixtures are having a similar effect on plants nearby.

Unless the lights are putting out the correct UV spectrum they shouldn't affect your plant growth in any way.

Additionally, being floodlights, I would expect them to be up rather high, further reducing the chance that they'd affect the plants.

I learned just enough to be dangerous about lighting with regard to plants while growing tomatoes indoors two winters ago.

quote:

Originally posted by Fenris:
I hate motion sensor lights. I keep my outside LED floodlights on from sunset to sunrise using astronomical timers. I suspect the constant light may be killing grass and hedges.

Has anyone else ever run into this?

I don’t know, but I’m sure glad you’re not my neighbor; I like it dark at night. I’m funny that way

quote:

Originally posted by TMats:
I don’t know, but I’m sure glad you’re not my neighbor; I like it dark at night. I’m funny that way

There's enough distance and trees so not to be an issue.