How to grow calamondin?

Planting Calamondin in the Ground

The cultivation of calamondin in open ground is only possible in a few regions with mild winters, where frosts are rare and short, or even non-existent. The Mediterranean coast, some privileged areas of the south-west basin, or regions with tropical climates overseas are therefore the only ones suitable for its garden cultivation. Its hardiness is indeed very limited: our citrus tree begins to suffer from the cold at -2°C and cannot withstand temperatures below -6°C.

The Ideal Planting Period

In open ground, calamondin should ideally be planted at the beginning of spring in March-April, to take advantage of the gradual rise in temperatures. Autumn planting is also possible.

The Location

For your calamondin, choose a warm and sunny position, but not scorching. It should also be protected from cold winds, drying winds, and sea spray.

Plant it in deep, rich organic matter soil that is well-drained (which does not retain excess water). Avoid clay soils. In terms of pH, it prefers slightly acidic to neutral soils but dislikes limestone.

If necessary at the time of planting:

• rebalance the pH by adding heather soil;
• lighten heavy soils with drainage elements (gravel, clay balls, pouzzolane, etc.) or coarse sand;
• enrich sandy and poor soils with well-decomposed compost, manure, or potting soil.

Finally, as citrus trees do not appreciate root competition, ensure sufficient planting distance (at least 1.5 to 2 metres) from other plants.

The Planting

1. Soak the root ball in a bucket or basin of water for about ten minutes to allow it to rehydrate properly.
2. Dig a planting hole about twice the volume of the root ball.
3. Work the soil and enrich it with a handful of compost, manure, or other specific fertilisers (ground horn, dried blood, etc.).
4. Install a drainage layer at the bottom of the planting hole (gravel, coarse sand, clay balls, etc.).
5. Place the root ball in the centre of the hole, add garden soil or potting soil until the roots are covered, but without burying the grafting point (a sort of bulge at the base of the trunk).
6. Firmly press down with your fingers.
7. Create a basin around the base to better retain water (optional).
8. Water generously.
9. Mulch the base of the calamondin to retain moisture and space out watering.

A Calamondin in open ground

Planting Calamondin in a Pot

The calamondin can be grown in a pot, either:

• kept indoors all year round;
• moved outdoors during the fine days from May to October, then wintered in a sheltered spot during the cold season.

The ideal planting period

Planting the calamondin in a pot can be done either in spring, between March and May, or in autumn.

Repotting occurs every 2 to 3 years, depending on the growth of the citrus tree. In years without repotting, proceed with a top dressing: remove the substrate to a depth of 3 cm and replace it with fresh potting soil.

The container

Choose a container with a diameter about 2 times larger than the root system, in which your citrus tree will not feel cramped. Opt for a container with drainage holes to allow excess water to escape without suffocating the roots.

Prefer a terracotta pot or a wooden box, which are more breathable than plastic containers.

For repotting, simply choose a container that is larger than the current one.

If you need to move your calamondin during the year, we recommend placing it on wheels.

The substrate

The calamondin prefers fertile soils, rich in organic matter, but light and well-drained.

To keep it simple, obtain a potting soil for Mediterranean plants or a special citrus potting soil, which promotes both plant growth and flowering and fruiting.

If you prefer to make your own mix, choose:

• 2/3 of high-quality horticultural soil or non-calcareous garden soil;
• 1/3 of coarse sand or gravel to enhance drainage;
• 1 to 2 handfuls of household compost or well-decomposed manure.

The planting

1. Soak the root ball in a bucket or basin of water for about ten minutes to allow it to rehydrate deeply and to facilitate the removal from its original container.
2. Install a drainage layer of about 3 to 5 cm at the bottom of the new container (gravel, coarse sand, clay balls, broken terracotta…).
3. Add the substrate mix until half full.
4. Remove the old container from the citrus tree and gently loosen the root ball with your fingers.
5. Place the calamondin in the centre of the container, then fill with substrate. Be careful not to bury the grafting point.
6. Firm down with your fingers.
7. Water generously.
8. Install a mulch to protect the base of the plant.
9. Add a saucer under the container.

The exposure

Place your potted calamondin in a sunny position, but sheltered from cold, drying winds. If possible, set it outdoors in the garden, on the terrace, or balcony as soon as the last frost risks have passed and until autumn (from April-May to October-November depending on the regions).

Indoors, position your citrus tree in a bright spot, but shielded from the hottest rays of the sun. Avoid proximity to a radiator or any other artificial heat source (fireplace, stove, etc.). Also protect it from draughts.

Note: while the calamondin is self-fertile, meaning it does not require the presence of another tree to bear fruit, its flowers need to be pollinated. Indoors, in the absence of pollinating insects, you will need to use a small brush to replace them if you wish to have fruit.

The flowers of the Calamondin need to be pollinated using a brush when grown indoors

Caring for Calamondin

Soothing watering and fertilisation are key points for a healthy calamondin.

Watering

The calamondin prefers its soil to remain cool, meaning moist but not overly wet.

In the ground, watering should be regular and generous, especially during the first few years, allowing the citrus tree to develop its root system. Plan to water once a week in summer, more often during prolonged dry spells or heatwaves. Gradually reduce watering in autumn, then stop in winter, unless there is a complete lack of rain.

In pots, the substrate dries out more quickly than in the ground. Check the soil with your fingers: as soon as it feels dry in the top few centimetres, it’s time to water. Empty the saucer about twenty minutes after watering or after heavy rain. If your calamondin is grown indoors year-round, regularly mist its foliage and place a layer of clay balls in the saucer. This will help increase ambient humidity.

Prefer rainwater to tap water, which can be too calcareous for the calamondin.

As indicated in the planting tutorials, don’t hesitate to mulch around your citrus tree to retain moisture longer and limit evaporation.

Fertilisation

Like all citrus trees, the calamondin is a heavy feeder.

In the ground, add well-matured compost or manure at the beginning of spring. Lightly scratch the soil to incorporate it into the substrate. You can also place ashes at the base of the plant: their natural richness in potash promotes fruiting. From late spring to summer, you can supplement with fertiliser for fruit trees or fertiliser for Mediterranean plants.

In pots, fertilisation should be more regular, as the nutrients in the substrate deplete quickly. Apply specific fertilisers from early spring to late summer. You can choose fast-release liquid fertilisers or slow-release solid fertilisers. For quantities, refer to the usage instructions on the packaging.

Pruning

To maintain the naturally round shape of the calamondin, prune at the end of winter after harvesting the fruit. Slightly shorten the new shoots. Using a pruning shear that has been disinfected, also remove any damaged or dried branches.

You can also remove crossing branches to allow for better air circulation and let more light in.

To prevent the development of fungal diseases, you can use healing paste on the cut wounds.

For more information, check out our article: “Citrus: when and how to prune?”.

Pests and Diseases

When grown in the ground, the calamondin is generally not very susceptible. Just be careful not to damage its roots when working around the base of the plant, as this can open the door to potential diseases.

In pots and confined spaces, the calamondin may suffer from red spider mite attacks. Regularly mist the foliage as a preventive measure. For treatment, shower the aerial parts to dislodge the unwanted pests.

Scale insects can be removed manually using a cotton swab dipped in alcohol.

Wintering

Not very hardy, the calamondin can only withstand very short and mild frosts. In the ground, protect its base with a thick layer of mulch and add a winter fleece around the aerial parts in case of forecasted frosts.

Bring your potted calamondin indoors, or into an unheated room (temperature between 5 and 10°C), but ensure it is well-lit.

To learn more, read our article: “Wintering orange trees, lemon trees, and other citrus.”