Key Lime Tree (Citrus aurantifolia)

Key Lime, also called Mexican lime (Citrus aurantifolia), is a fine small tree that can easily be grown in a sunny spot in the backyard or on the patio. It is resistant to disease and pests, plus the healthy tree produces small fruit and is famous as the lime of choice for Key Lime pies and bartenders around the world.

But that’s not all. Key Lime trees are attractive plants, and their dark glossy green foliage and bushy canopy make them excellent specimen trees for formal or informal gardens, as well as attractive trees for ornamental container growing.

I. Plant Profile – An Overview of the Key Lime Tree

Common name	Key Lime, West Indian lime, Mexican lime
Botanical Name	Citrus aurantifolia
Class	Dicotyledons
Family	Rutaceae
Genus	Citrus
Species	Key Lime
Plant Type	Tree, Shrub
Bloom Time	Spring
Hardiness Zone	4 – 11
Mature Height	8 – 12 ft.
Mature Width	5 – 8 ft.
Sunlight	Full – Partial
Growth Rate	Moderate

II. Key Lime Tree Appearance

Key Lime is a small bushy tree, rarely more than 3 meters tall. The slender branches have short to medium-sized thorns. The thornless ones are more compact and upright, with dark green leaves, stout and fruitless.

A key Lime tree has small leaves, and pale green in color. Its leaves have blunt tips and densely arranged narrow winged petioles. It also has flowers clustered in axillary clusters along the stem. They are fragrant and small, consisting of white petals, an upper ovary and nine stamens. Flowering occurs throughout the year, but mainly in spring.

Key lime fruits are Small, about 1.5 to 2 inches in diameter, round to oval in shape, with 10 to 12 internodes around a small, solid shaft. The rind is thin, smooth and leathery, turning greenish-yellow to yellow at maturity. Flesh is greenish-yellow and juicy, with a strong acidity and a distinctive aroma.

III. Key Lime Tree Growing and Care Conditions

Key Limes need to be watered every other day for about a week at planting and then 1-2 times a week for the next 2-3 months. After establishment, occasional watering when it continues to dry out is all that is needed. An occasional application of a balanced fertilizer will promote Key Lime vigor.

Pale or mottled leaves may indicate a nutrient deficiency. Excessive fertilizer may stimulate shoots that are susceptible to pests and diseases. Light pruning to thin the canopy and remove problematic crossing or friction branches is best done soon after fruit harvest.

Planting

Choose a location that receives 6-8 hours of sunlight per day. In hotter areas, the plant will grow in the shade, but should be grown in full sun. For potted plants, mist the plant daily to maintain humidity, but placing a stone tray filled with water under the plant will allow the water to evaporate and supply humidity to the tree.

Choose a pot that is slightly larger than the shipment and has lots of holes in the bottom for good drainage. Plant in a well-drained soil suitable for acid-loving citrus. Plant them in the house, preferably near a window facing south, where they will get plenty of sunlight. You may also need to place the pot on a saucer lined with pebbles and mist the leaves with water daily to increase the humidity of the tree.

Light

If planted outdoors, place in direct sunlight for at least 6-8 hours per day. However, in hotter areas, you can place a grown tree in the shade but grown in full sun. 

Watering

Water deeply, usually once a week, to allow water to penetrate the roots. After watering, allow the top 2 to 3 inches of soil to dry completely before watering again. For potted Key Limes, try sticking your index finger into the soil about 2 cm deep. If there is moisture, refrain from watering until it feels dry at that depth. Stop watering when you see water coming out of the drainage hole at the bottom of the pot.

Fertilizer

During the warmer months of spring and summer, apply a citrus-specific fertilizer about once every six weeks. During the fall and winter, apply fertilizer every two to three months. Be sure to follow the directions for use on the fertilizer bag.

Soil Requirements

Key Lime is adapted to a variety of soils. Seedlings and aerially propagated trees are well adapted to the rocky soils of the Florida Keys and the extreme southern part of Miami-Dade County. However, salt damage from saltwater intrusion and windblown saltwater is a frequent problem for trees in the Keys.

It is a problem for the deep sandy soils, growth is vigorous, but fruit numbers tend to be low. Fruits are generally large, lack juiciness, and have thick skins. Key Limes drain well and do not become soggy.

Mulch

Mulching Key Lime trees in a home garden can help retain soil moisture, reduce weed problems under the canopy, and improve near-surface soils. Spread 5 to 15 cm (2 to 3 in.) of bark, wood chips, or similar mulch about 8 to 12 inches away from the trunk. If the mulch touches the tree trunk, the trunk may rot.

Pruning

In general, once a Key Lime tree is mature, pruning should be done simply by cutting off dead, broken, or diseased branches as soon as they are found. Also remove any suckers that have appeared near the base of the tree. Young trees may require light pruning to broaden the canopy, but unlike other fruit trees, Key Lime trees do not require heavy annual pruning.

Pests and Diseases

Key Lime is very hardy and has few pests. Occasionally, the beetle, leafminer, and citrus mite can damage young trees. Release beneficial insects such as parasitic wasps or use insecticides as a last resort to prevent insect damage. Neem oil is also effective. Diseases include lime anthracnose, collar rot, and Fusarium oxysporum. Key Limes kept indoors are rarely susceptible to these diseases.

Pollination

Key Lime trees are self-pollinating and will produce fruit on their own, but if you want to increase your yield, hand pollinate them. Simply stick a small, dry, fine-tipped paint brush into the center of each flower. Rotate the brush and collect the pollen on the brush. Go to the next flower and repeat this process until all flowers have been treated. Do this process once a day and do not wash the paintbrush until the end.

IV. Key Lime Tree Varieties

Key Lime bears fruit from seed, and there are few selected species. However, there are varieties without thorns, but unfortunately, they do not bear fruit well. Recently, the U.S. Department of Agriculture developed a variety whose fruit is about twice the size of a regular Key Lime and named it “Giant” Key Lime. This variety may not be readily available in citrus nurseries.

V. Uses of Key Lime Tree

Key Lime is a shrub or small tree popular as a fruiting garden tree. It is grown commercially because of its spectacular spring flowers and prized juicy, tart, fragrant fruit. This sun-loving fruit tree thrives in tropical climates and cannot tolerate a frozen garden environment.

Key Lime juice is cholesterol-free and a source of vitamins A and C. Key Limes are used fresh in limaids, mixed drinks, pies, and iced teas, and squeezed over seafood and other foods such as papaya and avocado to enhance their flavor. It is also used in bottled lime juice, carbonated and carbonated beverages. The main by-product is lime oil, which is used in cosmetics and perfumes.

VI. Why should you buy a Key Lime Tree

With a Key Lime tree, you can enjoy the fresh, sweet aroma of the Florida Keys in your own yard. With its delicious dark green fruit, this tree can produce an abundance of limes for your garden, deck, patio potting, or favorite room in the house.

Any sunny spot can enjoy the unparalleled flavor that only Key Limes can provide. Set it up in your favorite room and you can walk to the kitchen and bake an unforgettable homemade Key Lime pie, with real Key Limes within reach.

It is especially versatile because its small size makes it portable and can be planted and grown anywhere. In addition, Key Limes are pest-resistant by nature and can be grown organically.

You will love growing dwarf Key Lime trees. Make pies, make limeade, or share with friends and family. These limes pack delicious sweetness and tartness in a small package.

Key Limes are a great addition to a citrus container garden. This lovely citrus tree produces fragrant flowers that fill the house with a light, sweet fragrance. The lovely white flowers are followed by smaller Key Limes. This fruit tree grows up to 12 feet tall and 8 feet wide above ground, but remains small in containers. It can be easily pruned to be compact and still produce many Key Limes.

You can make a delicious Key Lime pie with the fruit you grow. Key Lime is a dwarf version of the Mexican lime. You don’t have to live in the tropics to enjoy the infamous bartender’s lime. This lime is perfect for making refreshing cold drinks or flavoring food and desserts. Get a lifetime supply of fresh Key Limes from your very own tree.

As a dwarf citrus, it can also be grown in containers. Northern residents will love its versatility as a summer patio plant and as a plant to brighten up the house during the winter months. Its fragrant white flowers bloom in winter, filling the house with a delicious sweet fragrance. It is evergreen, and its lush foliage looks great in sunny window rooms. When grown in containers, Key Lime trees never grow over 3 meters.

Even apartment dwellers can set up a Key Lime tree in a limited outdoor space. The fragrant winter blooms are followed by six clusters of Key Limes that remain deep green until ripe. Grow in garden soil, but must be protected from frost. For better lime fruiting, provide good drainage and a quality fertilizer.