It’s not unusual for some trees, shrubs, and perennials to look badly damaged & sick- or even dead after the cold winter months. Just because the leaves are brown, droopy, or sickly-looking does not necessarily mean the plant is dead. In some cases these ugly brown leaves will fall off and be replaced by new ones. Often, new growth and leaves may develop just beyond the point where the old leaves have fallen off.
DON’T be in a big hurry to start pruning! I urge you to wait until spring after plants begin their new growth. In mid-April (or even May) you can get a much better idea of how much winter damage a plant has suffered and you can determine if it needs pruning.
I can’t tell you the number of well-established plants that homeowners have dug up and discarded thinking they were dead. Remember- haste makes waste!
You can determine if a plant is dead or alive by scratching the bark with your fingernail or with a knife. The growth layer just below the bark will be green if the plant is alive. If it’s brown, the plant is dying or dead. This gives you a guideline of whether there is a need to prune. If only a portion of the plant is dead, you might be able to salvage it by pruning off the dead section.
In some cases plants look just fine, but all of a sudden they’ll begin to turn brown or a silvery-green color as the weather begins to warm up. This indicates that the root system was frozen or damaged during the cold winter months, and more than likely that plant will die.
Keep in mind that many ornamental grasses and perennials die back to the ground each year, so go ahead and cut them off an inch or two above the ground, as you would in a normal year. New growth will flush as it begins to warm up, so don’t be overly worried if the visible parts of your perennials still look dead.
Roses- Severe pruning of roses is done in late February or early March.
Hydrangeas –If possible do not prune off any more than 50% of the old growth. Severe pruning stimulates vegetative growth and slows the development of flowers. Certain varieties bloom on old wood, and shouldn’t be pruned until after the flowers fade. Many newer varieties bloom on either new growth, or a mixture of new & old growth, and have a more flexible pruning window.
Azaleas and Camellias- Some buds could have frozen and the plants may not flower, but do not prune until after their normal bloom time to try and save any flowers that might have made it through the winter.