Written by Adam Latham
Each year at this time of rapidly diminishing daylight, there’s a rush to get it all done before winter — to finish collecting the fallen leaves, clean gutters, cut the lawn for the final time, and cut back perennials, among other tasks. Remember that when winter arrives, your plants will be exposed to extreme environmental stresses like nor’easter winds, snow and ice loading, and arctic temperatures. Injury to plants caused by people using snow removal equipment and de-icing chemicals and by animals feeding on tender bark and shoots is also a cold weather concern. By instituting protection measures this fall, you may save yourself from added work and the disappointment of replacing dead plants or nursing an injured plant back to health next spring.
Environmental Injuries
To help avoid winter-burned leaves on broadleaf evergreens like hollies and rhododendrons, which are exposed to drying winter winds or are in full sun, apply an anti-desiccant when the temperatures are still in the 50s or wrap the plants in burlap. Several years ago I planted a small hedge of inkberry along the street in front of my house. Here in full sun, they bravely face an open windswept cornfield to the west. Each year I have applied an anti-desiccant to them via a small ready-to-use bottle. Last year it seemed like I pulled the trigger on that spray bottle a few hundred times. So this year, I’ll mix a larger batch in a two-gallon spray tank and avoid cramping my hand on the small bottle’s trigger.
If your mophead or lacecap hydrangea failed to bloom this year, it could be that the flower buds were killed by single digit temperatures last winter. This year, install a burlap barrier or wire fence around the plant and fill it with leaves or other natural insulating material to protect next year’s flower buds, which lie at the tips of the branches. This method obviously works best on younger, smaller plants.
Trees, shrubs, and perennials planted this year will benefit from an insulating layer of mulch over their fragile young root systems. If you didn’t mulch at planting time, it’s still not too late to get it done. At this point in the fall, don’t be too concerned about having to use mulch that’s coordinated with the rest of the mulch you’ve been using; you can do that in the spring. For mulching only a few plants, use whatever is available: shredded leaves, straw from a bale left over from fall decorating, or compost that’s bagged or from the bin.
Plant injuries from animals and people
The deer have begun seeking out alternative sources of food now that the leaves are gone, and the plants in your suburban landscape might be their next meal. Fortunately for me I’ve seen very little damage to my plants from these four-legged hedge shears, only some munching on a few young bottlebrush buckeye (which deer aren’t supposed to favor). The cemetery two lots down is the favorite place in my neighborhood for the deer to dine on a fine selection of arborvitaes and yews.
If winter browsing by deer is a problem for you, there are a couple of things you can do to protect your plants, including using physical barriers and deterrent sprays. For their favorites, such as arborvitaes and upright yews, installing seven-foot-high deer netting around the plants is the most effective method, although not the most attractive option. Set the fence a couple of feet away from the damaged plant and secure the netting to 2”x2” wood posts with cable ties. Deer netting can be draped over lower growing shrubs to deter browsing, but the deer will eat any plant material sticking through the net.
My wintertime skirmish is with the rabbits. Many rabbits live under the large and gangly multiflora rose hedge along one of my property lines. Here they gnaw the bark off the canes throughout the cold weather, to which I pay no mind. Unfortunately, they also savor the flavor of young blueberry bushes. Two years ago, I planted three bushes. The first winter they were nearly chewed to bits. With the added benefit of deep snow, the rabbits were able to nibble the branches down from the tips, leaving nothing but stubby twigs about a foot tall. Last fall I encircled the bushes with wire fencing and they escaped injury. I’ll do the same each fall until the plants are large enough to fair for themselves.
The field mouse is another winter nibbling rodent. They’re tiny, but can be effective plant killers. In addition to your garden shed, they will find refuge under a deep layer of bark mulch or under a canopy of low-hanging evergreen boughs. Under these mouse-cozy covers, they will gnaw the bark off trees and shrubs. If the mice remove the bark all the way around a tree, called girdling, the tree will die. You can help to prevent this problem by pulling mulch away from the trunks of trees, especially young ones, and removing very low-hanging branches on evergreens such as spruces and firs.
If you have your driveway plowed, set out stakes to protect your lawn and adjacent plants before the ground freezes. Take some advice from this snowplow operator — in the middle of the night it’s very difficult to locate an unmarked driveway under a foot of new fallen snow.
In late winter or early spring, take note of the browned foliage on evergreen trees and shrubs adjacent to our roads. It is particularly evident on arborvitae and white pines that are planted close to the street. The dead needles are the result of applying salt on our roadways. The fine mist that is generated by passing traffic accumulates on the foliage and desiccates it. On young plants, this often results in the death of the plant. There really isn’t anything practical that can be done to prevent the damage during the winter; just be more careful next time in choosing more salt-tolerant species to plant adjacent to roads.