Q. In the Spring I planted two Pinky Winky 'hydrangeas in "standard" form, meaning there's a four-foot-high trunk before they branch out. The trunks are about two inches in diameter and the nursery told me to be sure to protect the bark from deer over the winter. What kind of protection would be safe to wrap around my Pinky Winky trunks?
---Gail in Traverse City, Michigan
A: Now, you're probably all asking yourselves: "Did he make this plant name up? Or did he pick this specific question so that he'd have a chance to keep saying "Pinky Winky"?
Well, I didn't make it up. Pinky Winky is a hydrangea in the 'paniculata' species. Unlike the typical 'mopheads', which have big round flowers that you can make either pink or blue depending on the soil pH, 'panicle' hydrangeas have tapered, conical flowerheads whose color isn't affected by the soil type. This specific variety's flowers start out white and then slowly turn to pink—giving you bi-color flowers for part of the season.
Now: Gail says that hers is a 'standard' form, but that it has a really tall trunk before there are any branches—IS this really a 'standard'?
Technically, yes. In the weird and wild world of horticultural nomenclature, the term 'standard' can refer to several things, including "a tree or shrub with a single tall stem before the branches begin", whether that specific plant grows that way naturally or not.
…Which hers does not. If left alone at the nursery, it would grow into a big bushy shrub—the typical shape that most of us think of with hydrangeas. But these 'tree forms' have become very popular—a lot of plants are sold this way (the 'tree peony' comes immediately to mind, although I much prefer peonies in their natural form). And this species of hydrangea is naturally tall, making it pretty easy to 'train' the plants to look this way. (Maybe we should call these things 'non-standard standards'?)
Anyway, the trunk does need to be protected.
In fact, it's a good idea to protect all plants that have this form over winter, especially when they're young and their tender bark is very attractive to nibbling pests—which includes rabbits, mice and voles as well as deer. When I planted my wife's peach trees, I made sure to protect the trunks with tree guards for the first five or six years.
Back then I used a kind of spirally plastic with perforations. You could stretch it out almost in a straight line, but when you put it around the trunk it formed a protective cylinder. There are lots of variations out there, called tree guards and tree wraps and such. The important thing is to get material that's perforated and that expands with the growth of the trunk in the spring. You want to protect the bark, but you don't want to restrict it or trap moisture under there.
(So no duct tape, Cowboy Gardeners! It wouldn't breathe or expand.)
Ideally your protection should cover the entire trunk, especially when the plant is young and the bark is soft and tasty. Deep snow cover can allow usually low to the ground nibblers like rabbits to reach much higher up than usual, and deer typically begin browsing about three feet above the ground. And young bucks 'velveting' their antlers in the Spring can do as much damage as biters.
Speaking of biting, what about deer eating the branches and other stuff up top—especially if they do have deep snow to boost their 'browsing height'?
That question led me to do some research on how often deer damage hydrangeas, which led me to a great new resource from Rutgers—new to me, anyway—that rates landscape plants on their 'deerability' on an A to D scale. 'A' plants are the ones that deer won't eat—at least until they're starving; while a 'D' means that the deer bring condiments and silverware to your yard. Hydrangeas got a C, which Rutgers classifies as "occasionally severely damaged".
So yes, they do eat hydrangeas.
Now, it seems that hydrangeas in this species bloom on new wood (mophead types typically bloom on the previous season's wood), so wintertime nibbling might not damage the Summertime show. But you never want deer to get used to eating ANY of your plants. They're creatures of habit, and often return to landscapes that have proven to be easy pickings.
So I'd spray the top with a good deer repellant a couple of times over the winter. If the plant were small, you could theoretically go with a wire cage around the whole schmageggie, but this trunk alone is four feet tall. That would be a really tall cage. A couple of sprays—especially early in the season, when deer are looking for new places to dine—is going to be much easier. And a lot of people just don't want cages around their plants.
And even if you don't mind the look of cages, you still have to protect the bark, because mice and voles can easily squeeze through any kind of fencing to dine on your plantings—and those nasty little nibblers can do a lot of damage. So wrap it or soak it heavily with repellant, no matter what.