Calamondin orange trees are widely grown for ornamental purposes. These small-stature trees are popular for their fragrant flowers, and small fruits that are sour, but edible. Here are some tips for those who want to grow these trees.
Like many other citrus species, the Calamondin orange tree can be forced to bloom by withholding water till the leaves start wilting, followed by deep watering.
If you are looking for an easy-to-grow citrus plant, go for miniature varieties like the Calamondin, that can be grown indoors as well as outdoors. With the mesmerizing citrus scent of its flowers, and the eye-catching clusters of small, vibrant fruits, this citrus tree is ideal as a houseplant. Though the fruits are edible, they are quite tart, with mildly sweet peels. The tree is mainly grown for ornamental purposes, rather than for its fruits.
Calamondin is a Hybrid: The Calamondin orange tree belongs to the hybrid genus x Citrofortunella. This genus consists of intergenetic hybrids that are produced by crossbreeding certain species of the genus Citrus with the members of the genus Fortunella. The tree is a hybrid that is produced by crossing tangerine and kumquat. While tangerine belongs to the genus Citrus, kumquat belongs to the genus Fortunella. This tree has the edible properties of the genus Citrus, and the cold hardiness nature of the genus Fortunella. The scientific name of this hybrid is x Citrofortunella mitis (x Citrofortunella microcarpa).
The Calamondin Tree: This orange tree grows as a shrub, with a maximum height of around 7 meters. It has dense branches that start from the base. The plant may have some thorns, and it develops deep roots. The leaves are broad and oval, with slightly pointed tips and winged petioles. The leaves as well as the flowers are aromatic. The plant produces white flowers, that are born singly or in clusters of two to three. The round fruits have a diameter of around 4.5 centimeters. The peel is thin and aromatic, with a mild sweetness; and the juicy pulp has a few seeds. The tree blooms and produces fruits intermittently, throughout the year.
Calamondin Orange Tree Care Instructions
Choose the Plant
You can go for a young tree that is less than a year old, and wait for a year or two for it to bear flowers and fruits. Otherwise, get a two to three-year-old plant that will blossom right away. Get the plant from a reputed nursery, and make sure that you choose one that is not damaged or diseased.
You must choose the right pot for growing the Calamondin tree. The pot must be larger than the size of the plant’s root ball, and it must have good depth. You can get a ceramic, plastic, or clay pot with enough drainage holes. If the holes are located on the base of the pot, you could fill the drainage dish with some stones, so as to ensure air circulation. You can also fill the bottom of the pot with gravel or pieces of broken clay pots. The remaining space can be filled with a mixture of peat, perlite, and potting soil. A loam-based potting mix can also be used for this purpose. A slightly acidic pH range (6 to 7) is preferred for this tree.
Once planted, the Calamondin tree has to be watered thoroughly and placed in a location with full sun. Fertilizer is not needed at this stage. Six to eight hours of full sun is ideal for this orange tree. Indoor plants can be placed near a south-facing window. Supplementary lighting may also work for indoor plants. Exposing the tree to full sun during the summers may prove beneficial for blooming.
Let the Soil Remain Slightly Moist
The Calamondin orange tree needs regular watering, so that the potting medium (or soil) remains slightly moist (not soggy). Regular watering does not mean daily watering. In this case, water the plant as and when the top layer of the potting mix gets dry. Thorough watering is preferred as opposed to superficial watering. The frequency of watering has to be increased during hot weather. During the winters, you must reduce the watering frequency, because moist soil may result in root rot and fungal diseases.
Outdoor plants require more water than the indoor ones, especially during hot and dry weather. Though the plant is drought-tolerant to a certain extent, it is not advisable to let the soil remain completely dry for long durations. You must water the plant if you see the leaves wilting. In short, overwatering as well as underwatering may prove detrimental. Hard water is not good for this plant. In that case, add some vinegar to the water beforehand (one tbsp. vinegar is sufficient for a gallon of water). Vinegar lowers the pH of hard water which is alkaline in nature.
Keep the Plant Warm and Frost-free
In general, citrus trees like warm temperatures. They can tolerate temperatures higher than 100ºF. The Calamondin citrus tree is cold hardy. Though it can withstand temperatures as low as 20ºF, the growth of the plant may decline once the temperature falls below 55ºF. In case of indoor plants, maintain a temperature of around 70 to 90ºF in summers, and 60 to 70ºF during winters. In colder regions, outdoor potted plants must be shifted indoors during winters. Moderate humidity is sufficient for this orange plant. You can place the plant on a tray of pebbles and water, or mist it in between. The indoor plant must get used to the new environment before it is shifted outdoors. Place the plant in the shade for a week, before exposing it to full sun.
Feed the Plant and Pollinate
Proper and timely application of fertilizers is a must for almost all citrus trees. You must feed the plant using a balanced fertilizer during spring and summer. Feeding can be done once in every three weeks, from spring to summer. You can also feed the plant lightly during autumn and winter. The fertilizer must be rich nitrogen, and must contain a good amount of phosphorous and potassium. Apart from these nutrients, orange trees need trace minerals too. So, get a fertilizer that has all these ingredients. As outdoor plants are exposed to different types of pollinators, pollination happens easily. Indoor plants have to be hand-pollinated, as pollinators do not have access to the flowers. All you need to do is to move a soft brush or Q-tip through the center of the flowers.
Grow Calamondin from Seeds
Keep in mind that citrus plants grown from seeds may take a long time to bloom. Some seeds may not germinate at all. If you want to grow these trees from seeds, it is better to use fresh seeds, rather than dry ones that may not germinate easily. Start the seeds indoors a month before the last frost. You have to use sterile soil for this purpose. Bottom heat is good for boosting germination. Removing a small part of the pointed tips of the seeds may also trigger germination. Once the seeds are planted, you have water the soil and cover the containers with thin plastic bags. The containers have to be placed in a warm indoor location. The seeds will germinate within two to three weeks.
When the seeds germinate, the containers have to be shifted to an indoor location where they will get enough light for growth. The plastic covers can be removed when the seedlings develop three to four leaves. The plants can be shifted outdoors as the temperature gets warm. They have to be placed in partial shade for a week, before exposing them to full sun. Once the seedlings grow to a height of around 10 inches, repotting has to be done. One-gallon pots can be used for this purpose. Repotted plants have to be placed at an indoor location with enough light. Once they establish themselves, you can shift them to partial shade and full sun. Repot them once again when they attain a height of around 2 to 3 feet. You can also grow new plants from stem tip cuttings during summer.
Pruning is done to keep the plant compact and manageable, and to trigger branching and blooming. Dead and diseased branches have to be removed as soon as you notice them. Shoots that develop from the main trunk and the roots need to be removed. Long and leggy branches can be pruned before spring. Mature plants have to be repotted once every 2 to 3 years.
Though Calamondin orange pulp is sour, it is excellent for making marmalade and jam. These oranges are mainly used for cooking. Calamondin orange juice is the main ingredient in some beverages too. Whole frozen oranges are also used to replace ice in some drinks.
In short, Calamondin orange trees are hardy, and growing them is not a difficult task. However, they are susceptible to pests like aphids, spider mites, scale, and whiteflies. Contact a horticulturist or your local nursery if your orange plant is affected with pests and diseases.