Lemon trees are part of the citrus family of fruits. Lemon trees are most often grown in warm to hot areas as they have very little cold tolerance. Dwarf varieties are available that grow indoors, but they produce an inedible fruit. Lemon trees require a lot of care to help them stay healthy and produce the best fruit possible.
Grow lemon trees in soil that is not clay heavy and has good drainage, says the University of Texas A&M. Plant lemon trees on the south or southeast side of the home for the best sunlight possible. When the tree is young, apply a 3- to 6-inch layer of mulch around the trunk (but not touching it), says the University of Florida. This increases water retention in the soil and prevents evaporation and drying out.
Citrus trees require infrequent, deep watering. Water every 2 to 3 days immediately after planting to establish the root system. After 2 to 3 weeks, increase the watering interval to around 7 to 10 days. Create a watering ring around the tree when planting to help you gauge when the tree is established. To create a watering ring, form a ring of soil around the tree trunk 2 feet across and several inches thick. Water will sink through the soil ring. The soil ring will naturally disappear after several weeks' times.
Apply fertilizer in the first few years of a tree's growth to stimulate the development of leaves and branches that bear fruit. Make the first light application of fertilizer 2 weeks after planting. Repeat every 6 weeks. Once the tree bears fruit, apply at the rate of 1 lb. of 8-8-8 fertilizer three times a year, says the University of Florida, in January to February, May to June and October to November. In the first year, apply three 1-lb. applications of 8-8-8, then raise it 1 lb. each year after that, until you reach a maximum of 8 lbs. per application.
Some lemon trees develop nutrient deficiencies. Symptoms show on leaves as wilting or spots. Apply a nutritional spray to the leaves of the tree to cure nutritional deficiencies; it will absorb into the foliage and the tree's vascular system. Garden centers carry prepackaged nutritional sprays. Apply according to the manufacturer's instructions on the packaging. Look for nutritional sprays that contain zinc, manganese, boron and copper.
Protect from cold from late November until spring to prevent damage to the tree branches and fruit on the tree. Mound soil around the tree trunk to protect young plants. For mature trees, drape blankets, tarps or covers over the canopy and secure to the ground for protection.