Before you go too far down a rabbit hole, do you know your soil pH? There are a lot of places in upstate NY where the pH is very high by eastern standards, and there are even places where the pH is high by any standard. The county Soil & Water people would probably be able to give you an educated guess (not Cooperative Extension, this isn't their area of expertise)

Hi @mad_gallica - thanks for the comment! We do actually - had it tested by a professional firm with various samples round the property - soil pH almost consistently 5-5.5. We transplanted a couple of rhodods from our old house and they're thriving - located close to the house so we hope will not be as attractive to the deer (assuming they are not deer resistant).

Would you consider spraying with deer repellent or adding randomly placed posts with irregularly zigzagging clear fishing line in winter? IME if deer are hungry enough little less will discourage them from eating green plants, and all the rhodies I know seem to have the same rather low level of deer resistance.

NH Babs - thanks. We'd not heard of the fishing line trick - we might do that around a couple of other areas but the drive could be problematic. Is there a deer repellent that works reliably and that you could recommend?

I typically don’t have deer issues though I did last winter so I will need something this coming winter. Plantskydd has a good reputation at least partly since it will last all winter for a fall application. Liquid Fence and Deer Off as well as coyote or bobcat urine may work well also, but may need more frequent application so would be better used in warm weather.

IME, the fuzzier the leaf, the less likely the deer will be to browse it. So something with a lot of indumentum might be best. However, you are in a pretty extreme zone for most rhodies so doubt things like the yak hybrids (most have both upper and lower indumentum) will work for you.

And deer will browse or sample any new shrub introduced into the garden, whether or not they may come back later for more of a meal :-) So I would second the suggestion of using repellent sprays.

Liquid Fence and Deer Off as well as coyote or bobcat urine may work well also

Operative term "fence" - if you don't fence them out you'll have to keep going out and spraying year after year. With any situation where nuisance animals have not been excluded by completely effective fencing being one where the ball is always in the court of the animals.

Hi everyone - thank you very much for the comments! Very helpful - we think we'll try two things: 1) fencing in where we can (closer to the house is possible there) and 2) the Plantskydd for shrubs further down the drive. Will see how it all goes!

My rhododendrons are ignored by deer in Zone 7A/B, NJ, but your zone is much colder and I would guess deer will go for them regardless. I hate those sprays more than the deer do..., I just plant things that deer ignore in my yard and let them walk for to the neighbors for the all night, open salad bar.