ANSWER: You don't have to wrap all evergreen conifers. Most of them are native to our climate, and are able to withstand the winter quite comfortably. The hard waxy covering on their needles usually protects the foliage against drying out.
But there are some occasions when conifers might need a bit more protection. These occasions usually always relate to the wind.
It's one thing to tolerate the freezing temperatures of mid-winter, but it's quite another situation when the wind howls. Just as humans can stand around waiting for the bus in minus-20 degree weather without getting frostbite, we soon rush for shelter if there's even a gentle breeze. The wind-chill factor comes into play, and our skin cools down to dangerously lower temperatures when the heat is sucked out of it by the wind.
The same thing applies to conifers.
They don't mind cold weather, but they have difficulty ignoring strong winter winds. Foliage that's constantly barraged by wind during extremely cold weather can soon give up what little moisture it managed to trap before the plant went dormant. And once that happens, the foliage will dry out and die.
The evidence of this is when we see surface foliage or whole sections of needles turn brown. We call it winterkill. Once foliage has died in this manner, the only way to handle it is to trim off the brown parts in the spring and let the healthier green foliage grow.
Winterkill might not affect very large conifers that are well established in their location, but it can be a problem for many of the smaller shrub-like trees or any conifer recently transplanted.
The highest risk is to conifers that are exposed in very windy locations.
Picture an ornamental thuja or juniperus planted near the corner of a house or in a side garden between two houses. The positioning of the buildings can cause an acceleration of even the normal winds. Plants like this will be prime candidates for winterkill, no matter how mature or hardy they are.
The easiest way to protect your conifers that might be at risk is to create a wind barrier around the plant, something that will cut the force of the wind back to manageable proportions. The cheapest method is to wrap the plant with a double layer of burlap, held in place by a few loops of garden twine. It's not very elegant, but it does the job. You can make it look a bit more professional if you put three or four stakes around the plant first, and then stretch the burlap over them. A cylindrical section of snow fence works well as a frame, as long as it's tall enough to hide the plant.
If you want to be even more discrete, replace the burlap with a new winter-wrap material, made of a layer of felt-like fibre bonded to a thin plastic film. It blends with the landscape much better than the sacking. Even one layer of this cuts the wind quite effectively.
This winter-wrap can be tied around the plant with twine, but it holds better if you staple it to a frame of wooden stakes.
Some people use this winter-wrap to protect their coniferous hedges against the damage caused by the salt used on streets.
If the fabric is stretched across posts in front of the hedge, it makes a very effective barrier against the salt, and is well worth the one-time investment.
--Canwest News Service
