I have a deer (or a very large rabbit) eating hostas in our back yard.
Would a motion detector security light scare it away? I don't want to
put any poisons or other such things out there.

I've learned it's more trouble than it's worth trying to keep deer away
from our plants. I either have to erect a tall unsightly fence, or rig up
something smelly/noisy that will deter them for a while. Dogs are more of a
nuisance than the deer, so that's not an option either.

We actually love to see the deer visiting our property, though sadly they
don't come around much anymore with all the development in our area. So, we
don't really want to scare them away anyway.

So, rather than fight with the deer, I've learned to work with them. I
avoid plants deer love to eat (hostas, impatients, etc.), and select plants
that deer don't particularly care for (marigolds, dianthus, etc.). The deer
may "sample" a plant every now and then if they are really hungry, but for
the most part they leave our plants alone. No fences or deterents needed.

In fact, I can usually sneak in a plant they would normally eat, as long as
it's surrounded by plants they don't like. Not 100% foolproof, but it beats
a fence.

Anthony