Question: Now that the snow has melted, we fear some of our garden plants may be dead. The leaves on many have turned brown and the heavy snow accumulation has almost flattened some of our evergreen shrubs.
Answer: There's no question that the recent arctic blast has taken its toll on our gardens. The extent of the damage may not be as bad as first thought however. Fortunately, most garden plants had reached their maximum hardiness and should have been able to withstand the sub-freezing temperatures. In addition, most areas received a heavy blanket of snow just in time to insulate plant foliage from the prolonged cold temperatures. The extent of protection depends on the depth of the snow. Generally, the temperature below the snow increases by about 2 degrees F for each inch of accumulation.
Snow brings welcome moisture to many landscape plants, which will in turn helps prevent desiccation injury. Even dormant plants continue to lose moisture from twigs (as water vapor) through transpiration. Evergreen plants, which keep their leaves through the winter, are at even greater risk of injury.
On the other hand, it is possible to have too much of a good thing. Some evergreens have suffered from too much of a snow load. The weight of snow and ice can bend or even break branches, particularly on multi-stemmed shrubs like arborvitae.
For now, the best advice is to take a "wait and see" approach to plant damage. Don't be in a hurry to charge into the garden with pruning shears and start whacking at dead looking wood. Wait until spring growth begins. Winter damage often won't show up until the plant starts to move sap through its system. Although some plants may look dead and have leaf damage, they will revive and begin growth. When you do prune, take out only what's necessary. Plants will recover faster with plenty of leaf surface left to help rebuild.
On the other hand, branches broken from the weight of snow and ice can be pruned now. Make pruning cuts flush against another branch if possible and do not leave small stubs at the ends of branches after pruning. If a branch has completely been broken off a tree, removing the damaged stubs will help keep the tree healthier. Improperly pruned branches with stubs left intact are more susceptible to disease entering through the decaying end of the branch.
Likewise, don't be in a hurry to prune plants where damage is limited to simply "bent" branches. Some of these will resume their natural position within a few weeks. Arborvitae and other plants which have copious amounts of foliage and therefore enormous weight on individual branches may need to be tied together and temporarily staked in order to regain their natural growth habit.
Question: During our recent cold spell we burned a lot of wood. Is there such a thing as putting too many ashes in the garden?
Answer: Wood ashes can be useful as a fertilizer and liming material in home gardens, particularly on acid soils low in potassium. Whatever the source of your ashes, the recommended application rate is no more than 10 to 15 pounds of ash evenly distributed per 1,000 square feet of garden area. Remember however, to never apply wood ashes to rhododendrons or other plants that prefer acid soils, such as blueberries and azaleas.