This appears to be related to root health and perhaps an establishment issue. Were they recently planted, sometime between autumn and this spring? If so, have they been regularly checked for watering needs? Even established evergreens can suffer damage in the winter if the prior autumn was dry, and it's not uncommon in recent years for our fall weather to have prolonged dry spells.

While evergreens like holly normally shed old leaves in spring, this amount of leaf shed is excessive and points to an underlying problem. Look on the trunk at ground level (or just below the mulch, if the layer is thick) for signs of chewed or missing bark - see link below. If found, this suggests voles may be responsible for killing too much of the sapwood that keeps the foliage hydrated and alive. The plant also appears to be leaning quite far to the side, since the plants in the background of the picture look upright and normally oriented. Did the plant partially blow over, or is it very close to a wall or other structure that it needs to lean away from in order to get light?
https://extension.umd.edu/resource/voles

We don't see obvious signs of pest or disease issues outside of whatever may have damaged roots. This could be a case of drastic winter burn, where moisture in the soil is locked-up as ice in cold periods when wind and sun dry out the foliage. Since the plant can't absorb the frozen water, the tissues suffer damage. On evergreen plants like holly, especially with their waxier leaves that lose water more slowly, this desiccation damage can sometimes not show up for weeks or months after it occurred, which is why winter burn usually isn't obvious until sometime in spring on affected plants. If this is what happened here, nothing can be done except to let the leaves shed (clean them up and dispose of them if you wish) and see if the stems send out fresh growth in the next few weeks. No signs of growth by early summer would indicate dieback that needs to be trimmed out, and if too many stems have died overall, the entire plant should simply be replaced instead.

If you'd rather not wait, you can do a test now to see if the branches are still alive. Using hand pruners or a pocket knife, scrape or nick a section the bark, perhaps the size of a couple rice grains or up to around half an inch long. Sapwood is located just underneath the bark, while the wood in the center of the branch is already dead - this is normal. Live sapwood will be green and may feel moist; dead or dying sapwood is brown, grayish, or off-white and will be dry. Dead wood is also usually harder to cut off with pruners/loppers than live wood; despite being more prone to cracking or breaking while being cut, it's harder to force pruners through dead wood than live.

Miri

Hi Miri,
Thank you very much for the quick response. Your assessment is helpful.

The Burford Holly have been established for nearly 4 years.  You are right about the leaning.  They, there is a group of 3, are part of the Enchanted Garden at the Miller Library.  From 3/20 till 7/20 the garden was closed even for maintenance. And possibly it is related to drastic winter burn as no one was checking over the winter either. I’ll check too for evidence of voles. I’ll do a clean up and wait and see if new growth shows up in the next few weeks before I make any drastic moves. Your are right about the leaning and I do not know what to make of it.  There is no impediment to light that I see and I don’t think the winds are strong enough to blow it over.  I’ll try to gather more information and keep an eye on it for now.

Thank you very much!
Ann

You're welcome.