Growth Requirements for Lime Trees

Climate

• Tahiti limes are more cold-hardy than Mexican limes. Key limes are especially sensitive to cold. To protect a young lime tree from sudden drops in winter temperature, wrap blankets or tarps over it and tie the corners down. If the cold is especially severe, drape plastic or tarps over a PVC frame. Use heat lamps or incandescent bulbs to provide heat under the cover. You can grow dwarf Key lime indoors in a 10- to 15-gallon pot. That will give you a tree that is 7 to 8 feet tall. If you live north of USDA zone 9, keep your tree outdoors starting in late spring and bring it back inside in early fall.

Soil and Planting

• Lime trees require a soil that drains well, and they do not thrive in heavy clay soil. If you have good soil, you do not have to mix in compost or peat. Plant your lime tree on the south or southeast side of your house to help protect it from the cold. If you buy your tree from a nursery, plant it in soil that is as high or higher than the surrounding area. This will ensure that it drains well. Build a raised ring around your tree to hold water. Keep this area free of weeds. Water your tree every few days for two weeks, then every seven to 10 days for two months. When the watering ring disappears into the ground, your tree should be established.

Fertilizer

• Horticulturalists at Texas A&M University recommend applying 1 cup of ammonium sulfate the first year of your lime tree's growth, 2 cups in the second year, and 3 cups in the third year of growth. Continue applying 1 cup for each year of the tree's age. Divide the applications in February, May and September.

Diseases and Pests

• Viruses that infect lime trees include crinkly leaf, exocortis, psorosis, tatterleaf, tristeza and xyloporosis. The Tahiti lime cultivar Citrus latifolia Tan. ‘No. 1’ is free of texocortis and xyloporosis viruses. The citrus red mite, also called the spider mite, can heavily infest the leaves and fruits. If possible, do not use pesticides to control mites. Wasp-like parasites of the genus Aphytis eat mites, and you can buy them at many garden supply centers. Use miticides that contain the active ingredient ethion. Apply a miticide and a fungicide containing copper four weeks after the petals fall and again in July and in the fall. Spray your trees with copper fungicides to prevent infestation of red algae that can split bark and kill branches.