The lime tree is native to tropical regions and can grow to 20 feet in height. Producing limes is not difficult if you pay attention to two elements: soil drainage and fertilizer. Lime trees cannot tolerate standing water around the rootball, so amending the soil to allow for adequate drainage is vital. Lime trees also need plenty of sunshine and high temperatures. They will be harmed if temperatures drop below 50 degrees Fahrenheit. Lime trees are hardy in USDA zones 9 to 11.
Determine how well the soil in the planting area drains. Lime trees, above all else, require excellent drainage. To test your soil, dig a hole 1 foot square and 1 foot deep and fill it with water. When the water drains, fill it again. Time how long the water takes to drain. If it takes less than two hours, add a 2- to 4-inch layer of compost to the soil to slow down the drainage. It it takes over six hours to drain, add 3 to 4 inches of sand or peat moss to the top 6 inches of soil to speed up the drainage.
Dig a planting hole for the lime tree. The hole should be deep enough to allow the top of the rootball to be 1/2 inch above the soil.
Remove the tree from the pot and wash the potting soil from the rootball. Place the rootball in the hole and fill the hole one-quarter with soil. Fill the hole with water and when it drains, fill it halfway with soil. Add the water again and when it drains finish filling the hole with soil, mounding it over the top of the rootball. The water helps remove air pockets from the soil. The air will dry the tree’s roots.
Water the lime tree to keep the soil moist until it is established. This generally occurs after one month of planting. After that, water every 10 days.
Fertilize the lime tree when new growth appears. Agriculturists at Texas A&M University suggest using one cup of ammonium sulfate during the first year. Apply it in three applications, 1/3 cup at a time, spaced evenly, during the growing season. Increase the amount of fertilizer to 2 cups during the second year and 3 cups in the third year. Place the fertilizer on the soil beneath the tree, spread it out to the dripline and water well to activate it.
Inspect the lime tree for insects periodically. Although no insect can kill the tree, an infestation should be controlled to keep it from spreading to more vulnerable landscape plants. Consult with your county cooperative extension agent for appropriate insecticides for your area.