For specific plant suggestions indicate where the garden is located. For not having how you garden dictated by wild animals fence them out.

It's in Maryland, and I'm in zone 7. Fences-- especially ones tall enough for deer-- are mostly not allowed by our HOA.

Effective deer fencing that I am acquainted with is hard to see wire deer netting stapled to peeler poles - maybe you can somehow talk the committee into allowing that.

Otherwise this is an example of why I would never buy into an HOA. You may get stuck with an ugly bare bottomed hedge because the rules there intended to prevent fencing or other "ugly" installations won't let you exclude the animals that are causing your hedge to look homely.

To solve the problem with under-planting not only will it have to include something that grows 5 ft. tall the planting will have to consist entirely of kinds that deer absolutely never go for, no matter how cold and snowy the weather. And are never nibbled down by rabbits as well - presumably you have those there also, or will at some point later.

In addition to being able to grow well and look attractive inside a conifer hedge, with all its roots and dryness.

Consider underplanting with ornamental grasses, etc.

Hellebores and epimediums will grow in the shade of the yews, and deer definitely don't touch them. They won't get more than a foot high or so, though. The colored hydrangeas (H. macrophylla) will grow in the shade, too. I find that deer may bother these unless you spray with a deterrent like Liquid Fence. I find that Liquid Fence is really effective in my high deer pressure yard.

is the hedge right on the property line, or do you have the option of planting behind it?

Your yews have made it to trees which form a beautiful screen, provide shade and block wind. Think of them as a pleached Allee. The bark of yew is attractive so no need to hide the bare legs. Prune them lovingly as an asset. I wouldn’t ubderplsnt them unless with a groundcover.

I think you csn work with what you have and create a beautiful formal tree hedge. Forget about protecting them from deer. It’s a lost cause snd in your case not necessary imho.

On the bright side, the deer have done a better job pruning than a lot of humans would have! And they're not killing the yews; the presence of those plants might help spare some other trees and shrubs from an untimely death.

Does your HOA allow wire cages for young plants? There are so many pretty plants that could fit in that space but it would be a shame to sacrifice them to the Bambi buffet.

I would probably cut them down and plant native hollies.

A tall, narrow ornamental grass like Karl Foerster or its cousin Calamagrostis arundinacea Brachytricha (shade tolerant) would work to hide the "knees" of those yews.

James