Mature lemon trees are known to flower and set almost year-round. The timing of major harvests is largely dependent on cultivar, climate and growing conditions. Typically, budded lemon trees begin making fruit the third year after planting. Trees grown from seeds will also eventually fruit, but it will take years longer. In either case, as the trees size increases so will fruit production.
How quickly a lemon tree matures and begin producing fruit largely depends on the propagation technique used to produce the plant. Lemon trees can be grown from seed fairly easily, but they will take about 15 years to start producing lemons. More typically, lemon scions are grafted onto the rootstock of related citrus species. This facilitates faster fruiting, as well as greater control and predictability concerning the characteristics of mature trees. Properly grafted trees begin producing fruit in about three years.
Climate and Growing Conditions
Proper climate and growing conditions have a significant impact on fruit production throughout the life of a lemon tree. Lemons are best adapted to arid Mediterranean climates. While trees are somewhat cold tolerant, freezing temperatures will inflict harm. Plants can grow in hot and humid climates, but they are significantly more pest-prone. For best fruiting, lemons require full sun. Trees should be placed a sufficient distance away from other trees or structures to ensure no shading occurs.
Lemons take approximately four to 12 months from first flowering to harvest. Lemon fruit is round or oval in form with a nipple-shaped apex on one end. Lemon peels are light yellow and about 1/4 inch thick. The texture of lemons varies in degree of smoothness. Most varieties produce fruit that contains small seeds, although some types are seedless. Fruit grown in hot, humid climates tend to be larger and juicier than fruit grown in more arid climates. A lemon tree will yield approximately 18.1kg of fruit during its first year of production. Well-cared-for mature trees will produce about 45.4 to 90.7kg of lemons per tree annually.
Lemons turn yellow on the tree when mature; however fruit may be satisfactory in taste prior to colour change. Ideally fruit should be between 2 1/8 inches and 2 ½ inches in size. Avoid roughly handling lemons or picking fruit when wet to reduce oil spotting. Commercially, lemons are either manually spot-picked with clippers, or if too costly, harvested at once. Mass harvested fruit is graded for processing or fresh sale. Undersized fruit is discarded.