n at about age 20; commercial orchards are generally replaced when they reach 35 to 40 years in age. Although the trees would live longer, the fruit from old trees is generally smaller and poorer in appearance and more expensive to care for. Apple trees can withstand temperatures as low as -40 degrees C. Here in the United States apples mainly grow in Washington, Pennsylvania, New York, Michigan and California. The trees need a period of cold or dormancy to grow and bear fruit properly. So they cannot grow in tropic areas. Oranges on the other hand also were around in ancient times. Some experts have proved that they date back as far as 4,000 years ago according to ancient Chinese records. Oranges also come from the other side of the Atlantic. When Christopher Columbus sailed for the New World, he carried with him seeds of oranges and other types of citrus fruits. The seeds were planted on the island of Hispaniola. Just as the Europeans spread apple trees westward in the United States by moving further that way. The Indians spread citrus trees beyond the Spanish Plantations by dropping seeds from fruit they were eating. Soon groves were of wild citrus trees. Orange trees never stop growing. By the time it is 20, it may be 4.5 meters (15 feet) high and producing more than 1,000 oranges yearly. Just as apple trees get old and stop producing quality fruit there are few orange trees over 100 years old that still produce quality oranges. Citrus trees are called evergreens because they have leaves in all seasons. Actually the old leaves fall off and new ones are constantly being produced. Citrus growers like apple growers have to protect their hard-earned crops from extremes in temperature. Even though Oranges are mostly grown in the tropics, a sudden drop in temperature can cause disaster. For these reasons fuel heaters and wind machines a...
