Lemon trees (scientific name Citrus limon) of all types are common around the tropical world. Not only are they used in agriculture, they are found in gardens and growing in the wild. They are closely related to oranges but are slightly less tolerant of the cold.
Lemons are thought to be native to China or northwest India. They were introduced to Europe in the 200 A.D. and then were spread to the New World by Christopher Columbus in 1492. They are now grown as an agricultural crop in tropical climates all over the world. In the United States they are primarily grown in Florida, California and Arizona.
Lemon trees grow to be about 20 feet tall. They have dark-green oval-shaped leaves that are about 2 1/2 to 4 1/2 inches long. The twigs on most varieties are covered with sharp thorns. The fruit is green before it ripens to yellow and is covered with a thick leathery skin that is high in oil content. They produce fruit all year, with the peak being in the summer months for most types.
Lemon trees need a soil that drains well. They are very adaptable to infertile soil and can be grown in clay if it drains freely. The soil should remain moist and be allowed to be slightly dry on the surface before watering. They need full sun and will grow in U.S.D.A. hardiness zones 9b to 11, but they prefer cooler days to help cure the fruit. Fruit can be ripened on the tree, but is usually picked while green and allowed to ripen in climate-controlled conditions.
Lemons are eaten fresh and sliced as garnish for food and drinks. The flesh is made into beverages like lemonade or for frozen concentrate and drink powders. The peel is often used to flavor pastries and candies. Lemon-peel oil is used for flavorings and as essential oil and is a component in soaps.
Trees can be used as a specimen plant or shaped into a hedge. Dwarf varieties are available for container planting and some have been adapted to bonsai.
Many different types of lemon have been developed. One of the most common is Lisbon, which produces a medium-sized fruit that is very juicy and has very few, if any, seeds. It is more cold tolerant than other types. Eureka is very similar to Lisbon except that it is less tolerant of cold and the tree is almost thornless. Meyer is a sweet lemon and is though to be a hybrid of lemon and mandarin orange. It is a smaller-sized tree and a good choice for the home grower.