Read a commented lime tree profile here with information about growth, flowers, leaves and winter hardiness. Lots of tips about successful lime tree care. This is how you plant a lime tree correctly.
What are the characteristics and care requirements of a lime tree?
A lime tree (Citrus aurantiifolia) is an evergreen shrub native to subtropical areas and bears sour, spicy fruits. It requires a location in full sun, a well-drained substrate and is sensitive to frost. Care includes regular watering, fertilizing, occasional cutting and overwintering in a light, cool room.
Profile
- Scientific name: Citrus aurantiifolia
- Genus: Citrus plants (Citrus)
- Family: Rutaceae
- Synonyms: Real lime, Mexican lime
- Origin: tropical belt
- Growth type: shrub, tall stem
- Growth height: 60 cm to 200 cm
- Leaf: oval, evergreen
- Flowers: fivefold
- Fruit: Berry
- Winter hardiness: not hardy
- Use: potted plant, fruit tree
Growth
A lime tree is small in growth and big in impact. The French term 'lime' is the diminutive of 'lemon'. Against this background, 'lime tree' more accurately describes the picturesque growth of the subtropical flower beauty with the aromatic, sour fruits. These properties make a lime plant a feast for the senses:
- Growth type: small, richly branched, thorny, evergreen flowering shrub with fruits the size of table tennis balls.
- Growth height: 0.60 m to 2 m as potted plants, 4 m to 7 m in tropical and subtropical areas.
- Advantageous attributes: shiny leaves, lush flowers, juicy, refreshing fruits, intensely scented with lemon.
- Gardeningly relevant characteristics: high heat and light requirements, slow growth, sensitive to frost, tolerates cutting.
Video: Citrus expert Dr. Dominik Große Holtforth talks about the lime tree
Bloom
An attractive flower festival is the atmospheric overture for the edible fruit decoration. Because a lime tree can bloom several times per season, inflorescences and limes can often be admired at the same time. All important flower properties in a nutshell:
- Inflorescence: racemose with several individual flowers
- Single flower: star-shaped, five-petaled, 1 cm to 5 cm in diameter.
- Flower color: white
- Special feature: purple flower buds in full sun.
- Flower properties: strong lemon scent.
- Position: in the leaf axils.
- flower ecology: hermaphrodite
- Flowering period: May to September (in harsh winter climates), April to October (in mild wine-growing climates).
Fruits
Because busy insects and the wind take care of pollination, almost every flower turns into a lime with these characteristics:
- Fruit shape: round, berry-shaped.
- Fruit size: 3 cm to 5 cm in diameter.
- Shell: green, later yellowish-green to pale yellow.
- Fruit: green, numerous seeds, sour taste with a spicy note.
Leaf
The evergreen leaves gather to form a dense crown, which forms a dark green canvas that makes the white flowers shine. Thanks to their decorative foliage, lime trees are worth seeing as potted plants even without flowers or fruit. These properties characterize the individual leaf:
- Leaf shape: oval
- Leaf size: 6 cm to 8 cm long
- Leaf color: dark green
- Texture: leathery, matt shiny
- Special feature: lemon-scented, edible
Between the leaves, a lime tree is armed with thorns up to 1 cm long.
Winter hardiness
Lime trees are not hardy. In their subtropical habitats, citrus plants have not learned to survive in temperatures close to freezing. The cold-sensitive potted plants start to shiver when the thermometer drops below 10° Celsius. This makes the real lime more sensitive to frost than Asian citrus plants, such as chinotto or orange trees, which can tolerate temperatures of 0° to 5° Celsius for short periods.
Planting a lime tree
When you buy a lime tree, you receive a shrub that has been refined into a trunk. The quality of the refinement is a decisive factor in successful cultivation as a container plant. As a purchasing source, competent tree nurseries and garden centers therefore have a better quality offering compared to mass-produced goods from discounters. Read these constructive planting tips about purchasing, location, substrate and planting technology for a lime plant in top form:
Buy a lime tree
The best time to buy is in March and April. In spring, regional citrus suppliers receive new lime plants from Italy and Spain. Numerous species compete with the common lime for the name lime tree. The following table shows the selection options:
| Lime tree species | Botanical name | Synonym | Fruits | Taste | Price | Buy height |
|---|---|---|---|---|---|---|
| Real lime | Citrus aurantiifolia | Mexican lime | round, green bowl | sour-spicy | from 49, 90 EUR | 60-80 cm trunk |
| Persian lime | Citrus latifolia | Common lime | oval, green-light yellow shell | sour, seedless, aromatic | from 29, 90 EUR | 40-70 cm trunk |
| Roman lime | Citrus limetta | Pursha lime | round-flattened, yellowish-green | sour-mild, similar to Calamondin | from 69, 90 EUR | 120 cm trunk |
| Kaffir lime | Citrus hystrix | Mauritius-Papeda | pear-shaped, wrinkled shell | sour, low in juice | from 169, 90 EUR | 180 cm half trunk |
| Caviar-Lime | Citrus australasica | Finger lime | cylindrical, green-yellow shell | sour-penetrant | from 69, 90 EUR | 110-130 cm trellis |
| Mandarin Lime | Citrus limonia | Rangpurlime | round, orange flesh | very sour, suitable for seasoning | from 39, 90 EUR | 70-80 cm trunk |
Location in summer
The lime tree is an unconditional sun worshiper. The potted plant prefers to enjoy the unfiltered sun on the balcony or terrace from May to October. All other requirements for the optimal summer location follow:
- Full sunny location (ideally on the south-facing balcony).
- Warm and surrounded by air (congested heat in front of a south wall sheltered from the wind is desired).
- Temperatures from 10° Celsius until the end.
- Important: no shadows cast by other potted plants, privacy screens, balcony railings or house walls.
Room gardeners without a balcony or terrace place a lime plant in the winter garden or in the sunniest window seat.
Location in winter
In the right winter quarters, a lime tree copes with the lack of light without dropping its leaves. A real lime wants these general conditions from November to March:
- Bright and cool at 10° Celsius to 15° Celsius
- Basic rule: the warmer, the brighter - the cooler, the less light.
Suitable winter quarters are all slightly temperate rooms with direct sunlight. These include a winter garden, cold house, staircase, glazed terrace, bedroom, guest room or a winter tent. If winter comes with cloudy skies, supplementary plant lighting can prevent leaves from falling off.
Substrate
Plant the lime tree in a permeable, structurally stable substrate that can store water well and provide nutrients for the roots. Commercial potting soil does not meet these requirements. Special citrus soil from specialist retailers has all the important components in its luggage. If you mix the substrate yourself, please ensure a slightly acidic pH value of 5.5 to 6.5.
Planting
It makes sense if you repot a purchased lime tree in fresh citrus soil as soon as possible. Choose a light-colored pot with drainage holes in the bottom. Black planters heat up massively in full sun, which significantly limits the activity of the roots. How to plant a lime tree correctly:
- Place expanded clay, lava granules or clay shards on the bottom of the pot as drainage.
- Pour citrus soil up to half the height of the pot and form a hollow in it.
- Unpot the lime, place it in the hollow and fill in the remaining substrate.
- Press down the soil and water thoroughly with rainwater.
The first week in its new home, a lime tree stays in a partially shaded location so that its evergreen leaves can get used to direct sun.
Excursus
Lime – lemon – difference
Important difference for hobby gardeners: Lime trees are more sensitive to frost and more difficult to overwinter than lemon trees. The peel of a ripe, ready-to-eat lime is green. With a few exceptions (e.g. Citrus latifolia), yellow-skinned limes are overripe. A lemon (Citrus limon) with a green peel, on the other hand, is not ripe and is harvested with a rich yellow peel. Although the lime is significantly smaller, it contains twice as much juice as a lemon. Both fruits taste sour, with a lime scoring points with an extra portion of spicy flavors.
Care for the lime tree
When it comes to care, requirements vary depending on the season. A lime tree is easy to care for in spring and summer. When winter is just around the corner, demands increase significantly. Proper watering and fertilizing is good preparation for the delicate wintering. Read these tips for the best lime tree care indoors and outdoors:
Pouring
In summer, a lime tree is one of the thirstiest potted plants. After moving to winter quarters, the need for water decreases. Skilled watering simply explained:
- How often to water?: daily in summer, as needed in winter (soil is noticeably dry).
- How to pour?: penetrating until the saucer fills up.
- What to water with?: with rainwater or tap water.
- When to water?: in the morning or after sunset (never in direct sunlight).
- Extra tip: regular spraying of the evergreen leaves is very beneficial to a lime tree.
Fertilize
Beyond the sun's rays, additional nutrients provide your lime tree with the energy it needs to grow magnificently. This is how you fertilize the tropical potted plant in an exemplary manner:
- Fertilize the lime tree weekly from March to October.
- Add liquid citrus fertilizer to the irrigation water.
- Water before and after with clear water for best nutrient absorption.
Use a high-quality citrus fertilizer (€6.00 on Amazon) with an NPK formulation of 20+4+14, or at least 10+2+7.
Cutting
You can cut the lime tree like a lemon tree. There is a detailed tutorial dedicated to this pruning care, which you can read here. Tangible tips about timing and cutting in a nutshell:
- Time: extensive crown correction and thinning in late winter, light topiary during the summer.
- Preparation: put on thorn-proof gloves, plan each cut to avoid gaps in the crown.
- Cutting guide: Place the scissors 2-3 mm above an outward-facing leaf or eye.
- Thinning: cut off dead, unfavorably positioned and infected shoots just before the bark.
Wintering
The somewhat tricky overwintering of lime trees has already been discussed several times. Read a short summary of all the important aspects here. This is how you properly overwinter a lime plant:
- Stop fertilizing lime from October and water more sparingly.
- Put into winter quarters when outside temperatures are below 10° Celsius.
- Winter bright and cool at 10° to 15° Celsius with additional lighting if there is a lack of light.
- Spray regularly and check for infestation with spider mites or other pests.
Extra tip: To prevent the capricious autumnal weather from catching your lime tree cold, hang up a minimum-maximum thermometer. Here you can read the lowest temperature of the previous night the next morning.
Repotting
A lime tree is repotted when the pot is completely rooted or the first roots grow out of the opening in the ground. The best time is after wintering, early to mid-March. Given its slow growth, the Mexican lime should be repotted into fresh citrus soil every three years on average. In the new pot, the distance between the root ball and the edge of the container is a maximum of two fingers' width.
Diseases and pests
Far from its subtropical home, a lime tree is susceptible to infestation with diseases and pests. Neglects in care also cause problems. The following overview lists common malfunctions and causes with tips for solving problems:
| malicious image | Cause | Countermeasure |
|---|---|---|
| Silvery speckles, gray-brown leaf spots | Spider mites | Spray regularly, fight with beneficial insects (predatory mites, gall midges) |
| Crippled, sticky leaves | Aphids | fight with soap-spirit solution |
| White webs, woolly pustules | Mealybugs | fight with soap-spirit solution |
| Yellow leaves | Chlorosis, iron deficiency | repot in acidic substrate, water with rainwater |
| Brown leaves | Drought stress | immersion in rainwater, water more often |
| Leaf shedding | Cold, lack of light | Change of location, additional lighting |
| Leaf shedding | Waterlogging | repotting, watering more moderately |
If strange branches sprout from the base of the trunk, this is no cause for concern. These are water shots. With rapid growth, these barren shoots strive to overgrow the grafted crown. Remove the uncontrolled growth with a bold tug or a smooth cut.
Popular varieties
Numerous, high-quality varieties have emerged from the various original species of the lime tree for cultivation as picturesque pot plants:
- Neapolitanum: historical, robust lime variety that was cultivated in the Medici gardens as early as the 16th century.
- Santa Barbara: refined Citrus aurantifolia with dark yellow to orange, sour fruits.
- Pursha: Cross between Citrus limetta and Citrus sinensis, rich in flowers and yields with mandarin-shaped fruits.
- La Valette: sour lime varieties with yellow-skinned, extra large fruits and compact growth.
- Lima Verde: Citrus latifolia from subtropical regions, beautiful, evergreen potted plant for the winter garden.
FAQ
My lime tree is losing leaves. Why is that?
Various causes cause a lime tree to drop its evergreen leaves. The most common trigger is a lack of light in the winter quarters. Furthermore, if you clear out a lime tree too early in the spring or clear it too late in the fall, the leaves will fall. The tropical citrus plant perceives temperatures close to freezing as a threat and throws off its leaves as a precaution.
Is it possible to overwinter a lime tree in the living room?
Wintering in the comfortably heated living room is possible if you provide additional lighting. Place the lime tree under a daylight lamp or special plant lamp. Experience has shown that at temperatures above 15° Celsius, at least 4,000 lux are required for a lime tree to retain its leaves.
Can you grow a lime tree yourself?
Theoretically, it is possible to grow a lime tree yourself from seeds. Remove the seeds from a fully ripe, yellow-skinned lime. A warm water bath makes the seeds happy to germinate. Sow the lime seeds in pots with a mix of citrus soil and coconut soil. In a bright, warm window seat, keep the seeds constantly slightly moist under a transparent cover. With a little luck, a lime tree will grow soon.
How long can I leave a lime tree outside in autumn?
If you have a location protected from the wind, you can leave the lime tree outside until the thermometer drops below 10°. The cold threshold is usually reached first at night. For this reason, it makes sense to hang up a minimum-maximum thermometer. The next morning you can read the minimum nighttime temperature on a scale and put the lime tree away in good time.
Can I buy a lime tree if I don't have a location in full sun?
The Tahiti lime (Citrus latifolia) is particularly robust and thrives even in slightly less sunlight. Choose a location protected from the wind with four to six hours of sunshine daily, either in the morning or afternoon.
