Warding Off Winter Damage In The Garden

The snowstorm that hit inland areas just before Thanksgiving only brought the East End rain, but the white stuff was close enough to give pause and remind us that winter, and all its destructive forces, is just days away. The past couple of winters have thrown just about every conceivable challenge at gardeners, and there’s no reason to believe that this winter will be any different. So the question is, what have we learned and what can we do to be ready?When I look back at the past two winters I think the issues we saw can be put into four categories: extreme cold, snow and ice, dry wind and hungry wildlife. Let’s take a look at each of these and see how we can plan and what remedies are at our disposal.

Light, powdery snow, even lots of light snow, tends to be less damaging than heavy, wet snow. But even before we get to your plants, let’s take a short look at your property and landscape. If your property or a neighboring one has large open lawns, pastures or meadows, a blowing snow can create drifts that can block driveways and access to important buildings. Snow fences that are correctly installed can control the formation of snowdrifts and serve the same function as vegetative wind breaks.

We have a driveway that passes through an orchard and gives access to a number of critical buildings. Because there’s an open field north of the orchard and because the prevailing winter winds at this spot are out of the north, every snowstorm results in the road being impassable due to drifting. The result is that we used to have to allocate lots of equipment and man hours to clearing this snow and treating the roadway. But about five years ago we started an annual ritual of installing an untreated (as opposed to ugly red-orange) wooden snow fence late each November that’s 120 feet long and 60 feet upwind of the road. Essentially what this has enabled us to do is manage the snow so the drifts no longer occur on the road but upwind of the road.

I think the rule of thumb is that for every 20 feet of snow fence 85 tons of snow can be stored and redirected. That’s a lot of snow that won’t need to be plowed or shoveled. There’s lots of information and instructions available online, so if you’ve got a drifting problem it’s worth a look. Be careful who you give the work to, though. Installed incorrectly, a snow fence can be just as much an enemy as a friend.

Then there’s the snow and ice that fall off structures, like your house, and crush the bushes and shrubs around your house. Evergreens are particularly susceptible to this damage and plants like boxwood, yew and arborvitae can be permanently damaged by these snow loads. There’s really only one way to protect from this kind of damage and it involves sheltering the plants in some way, shape or form. Burlap enclosures are one option, tying the plants is a second option and physical shelters built on wood frames using snow fencing or burlap are another option.

The option that’s used often depends on the talent and experience of the landscaper and your ability to withstand what can be a seasonal assault on your viewing aesthetics. Some object to the sarcophagus look of plants wrapped in burlap, while others find tied plants distasteful. And every year I’m asked if these protections are really necessary. I always answer no, they are not necessary. But do you really want to leave 50-year-old boxwoods unprotected during that one winter when that freak snowstorm crushes them?

Then there is the cold. No, you can’t stop it, but you can ameliorate it. I saw cold damage last year that I’ve never seen before. Rows of trees dead. Portions of shrubs with dead branches or portions of the plants that died from cold damage in the root zone. The worst situation is persistent cold with no snow cover. Remember that snow is one of the greatest insulators available. A heavy snowfall followed by 10 days to two weeks of bitter cold in the teens and 20s will result in little plant damage. The same temperatures for the same period of time with no snow cover will result in serious to severe damage. At least in my perennial beds, when I have the chance I bank and store the snow, and when I’m using the snow blower in my driveway I direct as much of the snow as I can into my planted beds.

Also be careful not to remove snow from your lawn. Last winter my son decided to use our snow blower to create an exercise track for our dog. He created a 30-foot-long figure 8 on the front lawn when there was nearly 2 feet of snow, and the dog loved her exercise track. But with all that snow insulation removed and temperatures often in the single digits, come spring we had a large figure 8 burned into our lawn that didn’t fully grow back in until mid-summer.

Think back to last winter and all those hydrangeas whose buds froze and died or the entire plants that died. Where these plants had snow cover we often saw the lower, snow-covered portion of these plants bud up and flower, while the top exposed branches and buds dried up and died from cold damage.

The other resource that will help against the cold in perennials and some shrubs is winter mulch. As I mention each year, the purpose of this mulch is to keep the ground not warm, but cold. This mulch is applied once the ground starts to freeze, and the mulch keeps the soil cold and stable through the winter instead of it going through multiple freezing and thawing cycles. This can be critical in spots that get lots of winter sun and are sheltered. There’s a downside, though, and you’ll have to gain some experience with winter mulches, as they can encourage rodents such as mice and voles. You’re providing shelter for them as well, and they will dig and gnaw under the mulch in some circumstances.

Then there’s the wind. Even out here, where we’re surrounded by water, the prevailing winter winds are out of the north. This wind tends to be cold, dry and desiccating. This condition can be most deleterious to evergreens, where we can see “burning” of needles on conifers such as pines and on other evergreens like arborvitae, some azaleas and rhododendrons. The obvious solution is to not plant these in highly exposed situations, but the other solutions are to use physical barriers such as burlap wind breaks, burlap wraps and liquid anti-desiccants that leave a plastic-like coating on the foliage that wears off after several months. These anti-desiccants are usually applied in December, then again in mid-winter, and they can also protect from sun scald, a type of sunburn that some plants get in the winter.

And last, but not least, there are those wonderful critters that get very hungry when it gets very cold. For the most part this means deer but those mice and voles can get pretty ravenous as well. As for the deer … fencing and repellents. Which repellent do I recommend? Many. There is no one repellent that you can apply once and keep the deer away. Bottom line? When the pressure is on and they’re starving they’ll even eat treated plants. The best advice here is to find two or three repellents that seem to work for you and alternate them regularly.

As for the fencing? Well, remember this. Your fencing may keep them out. But if they get over or under the fence … it will also keep them in. And don’t forget your driveway markers. I call them sod and curb savers. Keep growing.