I started a thread or two on deer last year. I planted a lot of elderberrys, and had them stripped bare. I used pepper spray and got them leafed back out. Then after the leaves fell in the fall, and I thought they were safe, they got used as antler rubbing posts, and badly broken down.
This spring I've been spraying them with pepper since the leaves first started showing, and had very little damage. The damage I got was a few nibbles right at first, and then during several days of steady rain when I skipped spraying because it would have gotten washed right off anyway. Now I take my sprayer for a walk through the elder every evening that it isn't actively raining. I have 50 plants on a quarter acre and I'm convinced that I wouldn't have any if I didn't keep up with the spraying.
I've started adding a little epson salt to the mix to improve the taste, and, maybe, help the plant. The mix I'm using is
3 Tbs Louisiana hot sauce (shake the bottle to be sure it's thin with no chunkiness, and, I like to see, "extra hot" on the bottle).
1 Tbs epson salt, (But, it works without this).
and, about a quarter tps sal suds dish soap to a gallon of water.
It's simple, and it works. Not sure, yet, what I'll do during antler rubbing season.