It's a well-known fact that hydrangeas are among the least deer resistant flowering shrubs on the market. That said, not all of the popular types of hydrangeas grown in North American gardens are equally savored by deer. Here's my ranking of hydrangea deer resistance, from least likely to be damaged to most likely, based on 7+ years of gardening with extreme deer pressure (up to nine adults in a quarter-acre lot at least once a week, year-round).
Important: While the information below is based on direct experience and observation, it's impossible to predict the behavior of wild animals like deer. To ensure the best blooming, anyone with deer in their area should plan to protect their hydrangeas, especially young and newly planted specimens.
Most deer resistant hydrangea: bracted hydrangea
You may not be familiar with bracted hydrangea (H. involucrata) but if you have deer problems, you definitely should get to know it! There are two big reasons why this seems to be largely unbothered by deer: its foliage is extremely soft and fuzzy, and deer despise that texture. It also blooms quite late in the season, so there are abundant food sources elsewhere when the tender buds are present.
Second-most deer resistant hydrangeas: bigleaf and mountain
Bigleaf hydrangeas (H. macrophylla) and the closely-related mountain hydrangeas (H. serrata) typify what comes to mind for most people when they think of hydrangeas: big, rounded pink, purple, or blue flowers atop a mound of thick, glossy green foliage. Surprisingly, these also seem to be the least-frequently-browsed types, with even the flowers left intact by hungry deer. Perhaps that thick, leathery foliage makes them less appealing - I don't know for sure, but I can say that even in my deer-ridden town, we get pretty stellar bigleaf hydrangea displays every summer. The new Cascade Hydrangeas would also fall into this group.
Somewhat deer resistant: climbing hydrangea
Like the less resistant hydrangea species that follow, deer may eat the flower buds of climbing hydrangea (H. anomala subsp. petiolaris) and its close cousin, false hydrangea vine (Schizophragma hydrangeoides), but by virtue of their unique climbing habit, damage is usually minimal, especially on established plants. Deer can only eat what they can reach, so once your plant has grown around 6' up the tree or other structure its growing on, its flowers are safe. Even damage to the plant itself is minimal, since it clings so closely to the tree.
Say farewell to the flowers: oakleaf hydrangea
Oakleaf hydrangeas (H. quercifolia) are native to North America and boast fabulous foliage as well as flowers. Those big, bodacious blooms give off a sweet honey scent, and attract pollinators - unless the deer get them first, and that's typically what happens in my garden. While some of the plants in my yard are mature enough that deer can't reach the topmost blooms, they do take off all of the flower buds within browsing range, if not during winter, than certainly in spring when the buds begin to develop. It's disappointing, for sure, but since oakleaf hydrangeas also offer beautiful fall color and a striking habit with dramatically peeling bark, they still contribute plenty of interest to be worth keeping around.
I have noticed that my Gatsby Pink oakleaf hydrangea manages to put on subsequent blooms later in the summer, and the deer usually leave these alone, so that variety might be worth a closer look to my fellow deer-ridden hydrangea gardeners.
Often seriously damaged: panicle hydrangea
Hardy, showy, reliable, versatile: panicle hydrangeas (H. paniculata) are extremely popular with gardeners of all skill levels. Unfortunately, they're also a favorite of deer, who don't just eat the flower buds but will eat severely in to the plant itself, leaving you with a bunch of stubby nubs. If you have a nicely established specimen, you are less likely to see this level of damage (though they will still eat all flower buds within browsing range), but if you are planting a new panicle hydrangea, you are definitely going to need to protect it for its first three or so years, until it gets larger and its stems get too thick and woody to be appealing to deer. Though panicle hydrangeas bloom on new wood, they are unlikely to create flower buds to replace those eaten by deer if the browsing occurs in mid-spring-summer.
And finally, the first choice of deer everywhere: smooth hydrangea
Also known as 'Annabelle' hydrangea, wild sevenbark, snowball hydrangea, and hardy hydrangea (or, botanically, Hydrangea arborescens), this beauty easily earns the dubious title of least-deer-resistant hydrangea. This is one that simply doesn't seem to stand a chance of growing, much less blooming, in areas where deer feed. Their stems and foliage are browsed as severely and frequently as the flowers, and in my yard, anyway, plants can't even put on a single new leaf without it getting chomped. Even though smooth hydrangeas are super hardy and easy to grow, I emphatically do not recommend this type for anyone visited by deer: not only does it get consistently eaten, it seems to have an almost attracting effect, drawing deer to the yard in the same way that other deer favorites like hosta, daylily, and arborvitae might.
We know this may be discouraging, but don't give up!
All of this information is not to deter you from growing hydrangeas if you have deer, but to help you find some measure of success. We've got a blog about the many ways that you can protect your plants if you need some ideas.
About the author: Stacey Hirvela is a professional horticulturist who has worked in gardens from the rooftops of Manhattan to the suburbs of Detroit. When she purchased her first home in a small town in West Michigan, she was surprised to find that despite its downtown location, it was visited nightly by a herd of deer that has only grown in the ensuing years. Gardening in these conditions is more challenging, but more enlightening, than any previous experience!