By Julie Christensen
Lime trees are among the most cold-sensitive of all citrus trees, growing outdoors only in warm, mild climates. But, you don’t have to live south of zone 9 to grow lime trees indoors. If you’ve got a sunny window with southern exposure, you can grow lime trees indoors no matter how much snow piles up outside.
Lime trees, with their glossy leaves and fragrant flowers, are gorgeous in their own right, but if you can bring a lime tree to harvest, so much the better. Lime trees typically need at least 3 to 4 years to bear fruit, depending on the size of your tree at purchase. They also need ideal growing conditions, including plenty of sunlight, adequate moisture and well-draining soil. Trees moved outside for the summer are most likely to bear fruit. Once the limes appear, they’ll take several months to mature on the tree. They do not ripen off the tree, but can be picked when they are sweet enough.
Planting and Caring for Lime Trees
The first step in growing lime trees is in tree selection. Opt for a dwarf variety for indoor growing. Dwarf trees have been grafted onto a dwarf root stock so the trees stay under 10 feet tall. Some grow less than 8 feet tall. Buy lime trees through a reputable nursery – preferably one that offers a guarantee on its trees. Lime trees are susceptible to some root diseases that can be contracted in the nursery. Starting with clean, healthy stock is absolutely critical.
Plant the lime tree in a plastic, ceramic or clay pot that’s slightly larger than the root ball of the tree. Make sure the pot has plenty of drainage holes. If you want to move the tree outdoors in the summer, consider choosing a pot with coasters so you can easily wheel the tree about.
Fill the pot partly with a light, loamy potting soil. The potting soil should be somewhat sandy and well-draining. When possible, use a potting soil made specifically for citrus trees. Gently place the rootball in the pot and continue filling it with soil. Tamp the soil down lightly and water until the soil feels moist to the touch.
Lime trees, like all citrus trees, need at least 6 to 8 hours of bright sunlight daily. Place your lime tree in a sunny window. During the winter, you may need to supplement the natural sunlight with a grow light, especially if the leaves drop or turn pale green. Keep lime trees at temperatures between 55 and 85 degrees Fahrenheit. A temperature of 65 F is ideal. Sudden changes in temperature can harm the tree, so don’t place it near heaters, radiators or exterior doors.
During the summer, you can move the lime tree outdoors. Wait until the last expected frost and then gradually move the tree outdoors, bringing it inside at night until it acclimates. Keep the tree on a patio or terrace in a protected area that gets full sun. Reverse this process in the fall – gradually bringing the tree indoors. It may lose a few leaves as it makes the transition from indoors to outdoors, but if you acclimate it slowly, it won’t experience too much shock.
Water the lime tree just enough to keep the soil slightly moist. Soggy soils promote fungal growth and root rot, so allow the soil to dry out slightly between watering. Lime trees appreciate humid surroundings so place the tree near a humidifier or mist its leaves with a spray bottle. This is especially important during the winter when the air is particularly dry.
Fertilize lime trees every three weeks from spring to summer with a citrus fertilizer or one made for tomatoes or vegetables. Fertilize at a rate of 2 tablespoons per tree, or according to package directions. During the fall and winter, fertilize every six weeks. Lime trees are prone to micronutrient deficiencies, such as iron and magnesium. Apply a micronutrient fertilizer each spring.
Lime trees don’t need the extensive pruning of orchard fruits, but you can prune them occasionally to remove dead wood or branches that rub against each other. You can also prune to control the tree’s size.
Lime Potential Pests and Problems
Disease problems are usually related to moisture levels and include root rot and fungal diseases. Provide well-drained soil and don’t overwater to reduce these issues. Aphids, leafhoppers, mites and scale all afflict lime trees. Before you bring a lime tree indoors for the winter, spray it with warm, slightly soapy water to dispatch any insects. If insect pests become a problem, treat them with insecticidal oil or soap.
Lime Varieties Worth Trying
The most important consideration is to purchase a disease-resistant variety that will stay small.
- ‘Persian’ limes (also called ‘Bearss’) are a favorite choice. They are a disease-resistant, naturally dwarf cultivar.
- ‘Eustis’ limequats are a cross between a lime and a kumquat. They have the flavor of limes and are more cold-tolerant.
Want to learn more about growing lime trees?
Visit the following links:
Growing Citrus Indoors in Cool Climates from Purdue University Extension
Citrus Trees: An Ideal Indoor Plant Selection from Colorado State University Extension
Hawkins Corner covers some of the basics of lime tree care: