Florida, in the southeastern United States, is called the Sunshine State. It grows more oranges than anyplace except Brazil. But Arctic air has damaged some Florida oranges and strawberries in recent days, and killed fish at tropical fish farms.
The unusually long period of cold weather has shown how even warm climates can sometimes freeze over. But protecting plants and trees in the garden may not be too difficult if you follow a few suggestions.
Sudden cold can be the biggest threat, especially after a warm period. Plants have not had a chance to harden their defenses. Those that are actively growing or flowering are at high risk.
Try to choose plants that live best with cold weather, and planting areas that face west and south. Being near other growth may also provide warmth.
Most frost damage takes place at night. Ice crystals form on the leaf surface. They pull moisture from the leaves and keep plant tissues from getting water.
Cold weather is most likely to damage or kill plants that do not have enough moisture. So keep the garden watered. Moist soil absorbs more heat than loose, dry soil covered with mulch or vegetation.
University of Arizona extension experts say covering plants and small trees with cloth or paper can help prevent frost damage. A one-hundred watt light bulb designed for outdoor use can also provide warmth. Some people place Christmas lights on young trees for warmth. The bulbs should hang below the leaves to let the heat rise into the tree.
Cold is especially dangerous to citrus trees. Agricultural specialists at the University of California suggest putting paper or cloth around the trunk and central branches of young citrus trees.
In Florida, as temperatures fell to record lows, citrus growers sprayed water on their trees to help prevent freeze damage.
Jim Bottcher is a master gardener with the University of Florida extension. He explains that as the water freezes, it produces heat, and the ice forms a protective blanket around the tree. If you spray a tree, keep the water away from nearby power lines. Heavy ice can form and break them.
You can also wrap a tree in palm tree frond leaves, cornstalks or fiberglass. Adding plastic film works well in rain and snow. But experts say plastic alone does not help much.
气温下降时如何给植物和树木保暖？
佛罗里达州，位于美国东南部，也被称作阳光之州，这个地区生长的桔子除了巴西之外比任何地方的都多，但是近来北极的冷空气对此地的一些桔子和草莓有所伤害，农场里的热带鱼也被冻死了。
长时间少见的寒冷天气意味着温暖的地方也会受到寒流袭击，但是如果你能按下面几点去做，在寒冷天气时保护好花园中的植物和树木也许不是件很难的事。
突然的降温是最大的危害，尤其是在温暖的气温持续一段时间后气温的突然下降，植物还未来得及采取必要的防护措施，尤其是那些处于生长及开花期的植物所面临的伤害最大。