Evergreen, in flower all year round and hung with small orange fruits so sharp they are better turned into jam, the calamondin (Citrus madurensis) is a cross between kumquat and mandarin and one of the very few citrus that tolerates a heated room. Give it bright light away from any radiator and it will keep fruiting indoors.
| Name | Citrus madurensis |
|---|---|
| Family | Rutaceae (Rue family) |
| Height | 3 to 6 ½ feet (1 to 2 metres) |
| Exposure | Full sun |
| Soil | Soil mix |
| Foliage | Evergreen |
| Flowering | All year round |
Repotting, care, watering and pruning are all good practices that will help you to grow a very nice calamondin.
Planting potted indoor orange trees
Typical planting of the indoor orange tree is soil mix enriched with fertilizer.
An ideal solution is to pour in a layer of gravel, clay pebbles or rocks to ensure that excess water drains well to the bottom. Make this layer about 1 to 2 inches (3 to 4 cm) thick.
Anticipate re-potting in a pot that is slightly larger than the previous every 2 or 3 years on average.
Repotting, feeding, watering and the summer holiday outdoors each have their own moment in the year. This table gathers the timings scattered through the sections below so you can see the whole cycle at once.
| Job | When | What to do |
|---|---|---|
| Repotting | Late winter to mid-spring, or late summer | Move to a pot only slightly larger, every 2 to 3 years |
| Pruning | Early to mid-spring, just after repotting | Optional: only to rebalance the silhouette or shorten branches |
| Feeding | Early autumn to midwinter | Citrus plant fertiliser throughout the growing phase |
| Watering | More from mid-spring to late summer, less in midwinter | Small amounts as soon as the soil is dry; in winter let the top inch dry out |
| Standing the pot outdoors | Late spring to late summer | Only once all risk of freezing has passed |
Turning the pot a quarter turn at every watering keeps growth even whichever season you are in.
It isn’t really necessary to prune it.
To rebalance the silhouette or reduce branch size of your indoor orange tree, prune just after repotting, preferably in spring.
You can also provide citrus plant fertilizer during the entire growing phase, from September to January.
Turn the pot a quarter turn at each watering so growth stays even.
Indoors, regularly water with small amounts of water as soon as the soil is dry.
Water your calamondin with rainwater or filtered water, since hard tap water pushes the soil alkaline and turns the leaves yellow between the veins.
In a heated room, mist the foliage or stand the pot on a tray of damp clay pebbles, because dry air encourages scale insects and leaf fall.
The indoor orange tree is a small fruit shrub that produces edible fruits. Sadly, these are so acidic that they’re not easily taken in. Make jam instead!
If you can, it is good to bring your indoor orange tree out after any risk of freezing has disappeared, from May until the end of summer.
Simply set it in a well-lit spot but avoid direct sunlight during the hottest hours.
Also avoid setting it right next to a radiator in winter because these tend to dry indoor plants up.
Dry heated air encourages red spider mites, visible as fine webbing and stippled, dull leaves on the undersides, so mist the foliage and check regularly.
Regular adding of citrus plant fertilizer will greatly increase blooming and fruit formation.
