The uncommonly warm weather of early winter makes gardeners nervous, but the greatest damage is likely to come not from the weather, which is within the predictable variations of our climate, but from improvised and makeshift efforts to protect plants.
Daffodils are showing green tips in some gardens, but in some years they do this as early as November, and if left strictly alone they come to no harm.
Last year was terrible for many plants, since there was no cold to speak of until Christmas Eve, when the temperature plummeted to zero. Many plants perished, not from the cold but from the sudden cold following a mild fall.
This year it already has been cold enough -- moderate freezes -- to freeze the earth a few days and to form ice an inch thick on six days. Plants slowed down this year, as they should, in mid-November, and although we have had only one sharp freeze in December, plants are in better shape than last year.
Many or most members of the rose family, including fruit trees, have put out sporadic flowers, more this December than usually. Yet it is a rare winter in which there are not a few flowers popping out on plums, cherries, forsythias, azaleas and Carolina jasmines. All these spring bloomers have their buds ready to open in mild weather, and a few days will do it. The plants themselves, however, as distinct from the trigger-happy flower buds, have held back in putting out leaves and coming into anything like spring growth.
Do not do anything in the garden to make things even warmer than they are. It is a mistake to wrap plants in plastic, which can act like a greenhouse. Then real damage might result. Sometimes people coddle camellias, for example, by building boxes with glass lights over them, and the winter sun (often brilliant in a cloudless sky in Washington winters) can heat the shelter exactly as it heats a car on a cold but sunny day. At night when the temperature drops, it is worse than if no protection at all had been given. Sometimes pampered camellias split their bark all the way to the ground, while unprotected specimens nearby are not damaged. Such plants are best when given a sheltered spot facing north, because you want them to thaw out gradually, not in the sudden heat produced against a wall facing south or east.
Gardeners soon learn that if the temperature goes to 70 or falls to 5 below zero, not a great deal can be done to alter the temperature. There is no way, obviously, to ram daffodils back below ground or holler at the plums to stop blooming. But a two-inch mulch (that is, a layer of excelsior or pine needles or leaves, preferably oak, which does not pack down so firmly into a soggy mess by February) will do much to prevent the sudden shifts from hot to cold, and will ensure a more gradual change in earth temperatures. Shelter in the form of wind screens of burlap (and good luck finding it) prevent many broadleaf evergreens like young hollies, box and so forth from becoming dehydrated or from receiving the full strength of a sun that may warm them up too quickly.
Even when temperatures set records for the date, it does not mean the weather is unparalleled. This year a warm record may be set this week, but another year a record may be set next week or last week. It remains a fact that winters have warm spells, springs have cold spells; sometimes it snows on the apple blossoms, and sometimes the basil is frozen in September instead of November. Nothing this year (thus far) has surprised the oaks or walnuts or cedars that in their centuries have seen much stranger weather than this. If pansies freeze when it suddenly turns cold or we have ice storms, well it is their nature to pull through some winters all right and to die in others. The best you can do is give them their mulch and hope for the best.
It is certainly better to do absolutely nothing than to run around with makeshift blankets. And unlike last December, which was truly outrageous, however many parallels there may have been in the past, this month cannot be half so bad since we have had some good freezes.
Some people fear that the forsythias will not be as showy as usual this March and April since they are blooming now. True. But since there is nothing short of holding ice cubes all day and night along their stems to prevent it, there seems little point in pouting. Most gardeners learn to relax once they comprehend there is nothing they are supposed to do and it's not their fault.