How to Plant, Grow, and Care for Calamondin Orange Trees

In the bright and vibrant citrus world, few plants have as many favorable characteristics as the calamondin orange. Its lush green leaves pop out of porch planters and create lush hedges that produce fruit. And oh, the sweet and tangy fruits—they’re not just a tasty treat but also appropriate for everything from cakes to salad dressings. And did we mention the plants can tolerate cold temperatures that zap many other citrus species?

If you’re still unsure about adding a calamondin orange to your garden, I get it. Experimenting with something new can be a bit scary! Yet diving into the unknown is one of the fun parts of gardening. Here is all the information and care tips you need to successfully cultivate these unique citrus fruits.

What Is a Calamondin Orange?

The calamondin orange, also known as calamansi or Philippine lime, is a hybrid citrus plant that’s a cross between a kumquat and a Mandarin orange. Plant scientists once thought the calamondin orange was a unique species (Citrus mitis), but they later determined it was a hybrid. Its scientific name changed over the years, but it’s mostly referred to as Citrus x microcarpa.

Native Range

Scientists think the plant emerged in the Philippines and parts of Indonesia, Malaysia, and Brunei. You can now find it growing throughout Southeast Asia and a few other portions of the world. The Philippines is the major producer of calamansi fruit.

Characteristics

No matter what you call it, the calamondin orange is versatile in the garden and kitchen. Like many fruit trees, the plant’s mature height depends on the rootstock. Wild plants can grow up to twenty feet tall, but dwarf varieties remain under five feet. 

All plant sizes have a woody stem that gives way to pliable branches. These branches are covered with shiny, dark green, evergreen leaves. The leaves have an ovular shape with rounded tips, making them stand out from the more pointed leaves of lemons and limes.

Calamondin orange plants produce flowers throughout the year, but spring is the main flowering season. The small white flowers have five petals and emit an attractive fragrance. Upon successful pollination, these flowers turn into fruits that eventually grow one to three inches wide. All fruits start out green, and the mature color ranges from orange to yellow to green. Some varieties also sport variegated fruits.

When you cut into calamondin oranges, you’ll see juicy flesh that resembles other citrus fruits. The flavor is more tart than sweet, with hints of lemon, lime, orange, grapefruit, and passion fruit. Each plant produces unique-tasting fruits, so you won’t know what a calamondin orange tastes like until you try it.

Planting

Growing calamondin oranges from seed isn’t the most reliable planting method, so purchasing a potted plant is the best way to add one of these trees to your home. Although it’s often difficult to find the plants in local nurseries, you can purchase them online. I recommend ordering your plants in the spring through fall since cold winter temperatures can damage the plants during shipping.

Before you choose a plant, be sure you research the cultivar. As I mentioned above, some calamondin oranges remain small enough for planters, but others grow into small trees. Pay attention to the rootstock and choose one that matches your needs.

Growing in Pots

Since some calamondin oranges remain small and compact, you can grow them in pots. Growing containers is especially useful in cold areas since it allows you to bring the plants indoors during the winter.

Choose a container that’s two to five gallons and ensure it has drainage holes on the bottom. The material isn’t important, but a lightweight pot is easier to move than a glazed ceramic planter.

Once you have a container, fill the bottom few inches with a citrus-specific potting soil mix. Remove your plant’s root ball from the original container, place it into the new container, then fill any remaining space with more potting mix. Water well and let the tree adjust to its new home.

Growing in the Ground

While many people choose to grow these citrus plants in pots, you can successfully grow them outdoors in the ground in zones 10 and warmer. Before you plant your tree in the ground, make sure you’ve identified a proper site. Avoid shaded areas or anywhere with compacted, wet soil.

Spring is the best time to plant calamondin oranges. Once you’ve found a suitable location, dig a hole a few inches larger than the plant’s root ball. Place the root ball in the ground and cover with soil.

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How to Grow

Calamondin orange trees are moderately easy to care for if you provide the following conditions.

Light

Calamansi require at least six hours of direct daily light to remain healthy. They thrive in areas with direct sun throughout the day. While they can survive with less light, they’ll experience slow growth and a lack of flowers.

If you’ve planted your calamansi outdoors, choose a location with full sun or partial shade. Place potted indoor plants in a brightly lit room near a south-facing window. If your house doesn’t have a bright location, utilize a grow light to supply supplemental lighting.

Water

Calamondin oranges prefer soil that’s moist but not wet. The plants’ water needs depend on the temperature, soil type, and humidity, so examining soil moisture is the best way to tell if your plant needs a drink. If the top two to three inches of soil is dry, thoroughly soak the soil or potting mix.

During the summer, expect to water your plants about once a week. Potted plants require water more often than plants growing in the ground since evaporation occurs more rapidly.

Soil

Like most citrus plants, calamondin oranges prefer a coarse, well-draining, slightly acidic soil. If you’re growing your plants in a pot, choose a soil mix designed for citrus plants. You can also create your own potting mix by combining:

• Five parts pine bark fines
• One part perlite
• One part peat moss or coco coir
• One part finished compost

Before you plant a calamansi plant in the ground, ensure the soil is well-draining and well-aerated. Sandy areas are best, but you can also improve the soil in other areas by loosening it with a broad fork and adding a few cups of finished compost.

Temperature and Humidity

Calamondin plants are more cold-hardy than other citrus plants but they will die in deep freezes. Plants will remain undamaged if temperatures drop to 30°F (-1°C) and can survive temperatures as low as 20°F (-7°C).

If you live in zone 9 or colder, you can still grow calamondin oranges. Just plant them in containers and move them indoors when winter arrives.

Although these plants can tolerate cold temperatures, they flourish in warm environments. Aim to keep the plants somewhere between 70-90°F (21-32°C) during the growing season. They aren’t picky about humidity but don’t thrive in extremely dry air.

Fertilizing

Calamondin orange trees require regular doses of fertilizers to grow, fight off disease, and produce an abundance of flowers and fruits. The easiest way to ensure your plant receives the nutrients it needs is to choose a fertilizer designed for citrus plants. These fertilizers contain the optimum blend of nutrients to support calamondin orange plants.

Citrus fertilizers come in spikes, granules, and liquid forms. Any of these options work well if you apply them following product instructions. A good rule of thumb is to split up the recommended annual dose into three applications. Apply one in January, the second in April, and the third in June. Avoid fertilizing in the late summer and fall since this can lead to low fruit quality and ripening problems.

Maintenance

Calamondin orange trees grow well with little maintenance, but regular light pruning helps keep them healthy. During the late winter, remove any dead, diseased, and criss-crossing branches from the canopy. Prune off any sprouts that pop out from the base of the trunk.

Other maintenance includes optional mulching. Mulching the surface of your soil or planter with wood chips, straw, or pine bark helps limit evaporation and trap moisture.

Propagation

If you want to grow a calamansi plant at home, start with mature seeds or cuttings. Calamansi seeds are polyembryonic, so each seed can produce more than one seedling. However, since the seeds are slow to grow into mature plants, home gardeners often propagate these plants from cuttings.

Once you obtain a healthy cutting, you can propagate it by rooting the cutting or grafting it onto a healthy rootstock. Since grafting requires advanced skills and a suitable rootstock, rooting cuttings is the easiest propagation method for home growers. To propagate your plant via this method, follow the steps listed below.

1. Obtain and Prepare a Cutting

Start with a healthy calamondin orange plant that’s at least two years old. Look for a healthy stem that’s at least eight inches long. Use a sharp and sanitized pair of pruning shears to cut the stem right below a leaf node. A node is where the stem intersects with the central trunk. The cutting should be six to eight inches long. Remove the leaves from the lower half of the stem.

2. Apply Rooting Hormone

Dip the cut end of the cutting into the rooting hormone. While this step is optional, it will greatly increase the chance of root formation.

3. Set the Cutting in a Suitable Container

Choose a container that’s four to eight inches deep, then fill it with a well-draining material. Some suitable options include perlite, coco coir, peat moss, or a loose potting mix. Use a pencil or chopstick to poke a hole in the material, then insert the cutting into the hole. Nudge the material around the sides of the cutting until it’s held securely in place.

4. Place in a Warm and Humid Environment

Water the material until it’s moist, then set the cuttings in a warm, humid area between 70-80°F (21-27°C). If your house or greenhouse is dry, cover the cuttings with a plastic bag or glass container to trap moisture and increase the humidity. Ensure the material isn’t touching the tops of the cuttings. Set the cutting in an area with indirect light.

5. Wait Until Roots Form

Keep the material moist but not wet while the cuttings form roots. Under the right conditions, roots emerge within a few weeks. Once the roots are an inch long, repot them into larger containers.

Harvesting and Storage

Since calamansi plants flower throughout the year, the fruits mature at different times. However, the main harvest occurs in the late fall and winter.

Color is the best way to determine if a calamondin orange is ripe. Many varieties produce orange fruits, but mature fruits may sport yellow and green stripes. Once your fruits turn their mature color, harvest them by gently plucking them off the tree. You can also harvest unripe calamondin oranges, but their flavor will be tarter than ripe fruit.

Store the fruits in the refrigerator for up to three weeks. If you plan to use the fruits for juice, you can juice all of them at once and then store the juice in an airtight jar. The juice will last up to two weeks in the refrigerator and up to six months in the freezer.

At room temperature, oranges should last at least a few days.

Common Problems

Calamondin oranges face many of the same problems as other citrus plants. Some problems arise from improper environment and care, and others are just natural occurrences. If you grow one of these plants at home, watch for the following problems.

Lack of Flowers

If you notice your plant looks healthy but isn’t producing any flowers, a few factors could be to blame. First, ensure your plants receive at least six hours of direct light each day. A lack of light leads to a lack of energy, preventing the plants from producing flowers.

Second, ensure you’re not over-applying nitrogen fertilizer. Too much nitrogen may lead to explosive vegetative growth but no flowers.

Finally, ensure your plant is mature enough to produce flowers. Plants won’t produce flowers during their first few years of growth, so don’t expect new seedlings to flower.

Yellow Leaves

If you notice your plant’s leaves changing from green to yellow, you know something is awry. However, it can be challenging to determine exactly what’s wrong. The truth is that there is a long list of possible causes of yellow leaves.

First, check the soil moisture. Both under-watering and over-watering can prevent plants from obtaining the water and nutrients they need to remain healthy. When it comes to under-watering, the soil simply lacks moisture. Over-watering can lead to rotten plant roots that struggle to take up moisture. Remember to water your plant about once a week or when the top two to three inches of soil is dry.

Next, take note of any sudden environmental changes. Moving your plant between the indoors and outdoors can lead to stress and temporary yellow leaves. Slowly acclimating your plant to a new environment helps limit stress.

Finally, ensure you’re giving your plant the proper amount of nutrients. Too little and too many nutrients can both lead to problems, including yellow leaves, so follow fertilizer application directions.

Sap-Sucking Pests and Diseases

Tiny pests like aphids, scale, and spider mites often appear on calamondin orange leaves and in node crevices. These tiny critters pierce plant leaves and suck out their sap. A few of these pests aren’t a big concern, but big outbreaks can weaken plants. If you notice these pests on your plant, wipe them off with a soapy rag or spray them with neem oil or insecticidal soap. 

Leaf mottling and citrus canker are two related symptoms of disease caused by the same bacterial pathogen. This bacterium causes lesions on leaves and fruit, as well as cankers that ooze orange in the branching nodes. Because this is such a debilitating and communicable disease, it is best to contact your extension office. They will advise you of the best course of action to take, which can sometimes mean removal of the tree.

Frequently Asked Questions