Key lime pie is just one of the many tasty dishes you can make with the small key lime. With one tree in your backyard or in a patio container, the key lime will provide you with many of this distinctive-tasting citrus fruits. You can start this heirloom fruit from seed, but you'll harvest your first limes sooner if you purchase a tree at your nursery. Because key lime is native to the tropics, you must protect it from frost when winter arrives--but you can grow it in a large pot, which you can bring indoors in colder weather.
Pull weeds and other unwanted plants from your planting area, which should be in a sunny area that is protected from cold northerly winds. If your soil is rocky, dig your planting hole twice as large as the root ball of your tree. If your soil is humus or sandy, dig the planting hole just slightly larger than the root system.
Mix two gallon buckets full of any type of compost with the soil you removed for the planting hole. Fill your hole up to a level that will accommodate the tree's root system without burying the trunk.
Remove your key lime tree from its nursery pot and set it into the planting hole, leaving it a bit higher than it was in its pot. Back fill with your soil/compost mixture and firm it down around the base of the tree with your foot. Water well.
Water your new tree three times a week for its first three weeks in the ground. After that point, water it once each week, allowing the soil to dry before you water again. Keep weeds pulled so they do not compete for water and soil nutrients.
Fertilize your Key lime tree with a plant food designed for citrus trees when it begins to send out new growth--an N-P-K ratio of 8-8-8 is adequate. Fertilize every six weeks during its active growing season, but do not fertilize during winter. If you spread a 2-inch layer of organic mulch or compost around the base of the tree, it will help to control weeds and will also give your tree continuous nourishment.
Spray your tree with insecticidal soap to control aphids, scale insects, spider mites and mealy bugs. If you have a problem with slugs or snails, bait with iron phosphate granules. Sooty mildew sometimes occurs--treat this condition with an approved fungicide or sulfur spray if you notice a gray or black residue on the leaves.