Calamondin (Citrus microcarpa) care

Herbs & edibles · straightforward to keep

Last updated 26 October 2026

Calamondin (Citrus microcarpa) wants full sun — the brightest position in the house. Water it every 6 days. Water thoroughly when the top few centimetres are dry, with rainwater if your tap is hard. Never let it stand in a saucer. Pot it in citrus compost, or a loam-based compost with grit — slightly acid. A citrus feed — summer formula in the growing season, winter formula from autumn. They are hungry and specific about it, and repot every 2 years. Humidity: above 50%. Mildly toxic to cats and dogs — the essential oils in the leaves and peel cause vomiting and, in cats, can irritate skin.

The calamondin: a small citrus tree with glossy leaves, fragrant white flowers and small, sour orange fruit, often carrying flowers and fruit at once. It is the easiest citrus to grow indoors.

Quick facts

Water: Water every 6 days. Water thoroughly when the top few centimetres are dry, with rainwater if your tap is hard. Never let it stand in a saucer.
Light: Full sun — the brightest position in the house.
Humidity: Above 50%.
Soil: Citrus compost, or a loam-based compost with grit — slightly acid.
Feeding: A citrus feed — summer formula in the growing season, winter formula from autumn. They are hungry and specific about it.
Repotting: Repot every 2 years.
Toxic to pets: Mildly toxic to cats and dogs — the essential oils in the leaves and peel cause vomiting and, in cats, can irritate skin. The ASPCA does not list Citrus microcarpa itself, but lists a relative, Calamondin Orange (Citrus mitis), as toxic to cats and dogs (checked 26 October 2026).
Difficulty: Straightforward.
Mature size: 60 cm–1.2 m in a pot.
Native to: The Philippines and Southeast Asia; probably a mandarin and kumquat hybrid.

Watering a Calamondin

Water every 6 days. Water thoroughly when the top few centimetres are dry, with rainwater if your tap is hard. Never let it stand in a saucer.

That cadence is the one PlantParlour sets for this species when you name it, and it is deliberately on the cautious side — a plant that asks a day early is safer than one that asks a day late. Log each watering and the reminder moves with the plant rather than with the calendar.

Light

As much direct sun as possible, and outdoors from late spring to autumn if you can manage it. Citrus indoors in poor light drop their leaves and never fruit.

Humidity and temperature

Above 50%. Central heating in winter is what turns a comfortable room into a dry one, and it is the usual reason an established plant suddenly browns at the edges or picks up spider mites.

Soil and potting

A free-draining, slightly acid mix. Citrus-specific composts exist and are worth using; ordinary compost plus hard water causes the yellowing you see on half the lemon trees in garden centres.

Feeding

A citrus feed — summer formula in the growing season, winter formula from autumn. They are hungry and specific about it. Stop feeding in autumn and start again when you see new growth in spring — feeding a plant that isn't growing just builds up salts in the pot.

Repotting

Repot every 2 years. Every second or third spring, one size up. Prune lightly in late winter to keep the shape.

Common problems

Yellow leaves with green veins
Iron or magnesium locked out by hard water or alkaline compost.

Fix: Use rainwater, repot into citrus compost, and use a proper citrus feed.

Yellow leaves: how to read it on any plant
Leaves dropping in winter
Too warm and too dark indoors.

Fix: Keep it cool (around 10 °C) and as bright as possible over winter, and water much less.

Leaves falling off: how to read it on any plant
Sticky leaves and sooty black mould
Scale insects — extremely common on indoor citrus.

Fix: Check stems and leaf undersides, wipe them off, and treat every week for a month.
Flowers but no fruit
Nothing pollinated them indoors.

Fix: Dab each flower with a soft brush every day or two while they are open.

Propagation

Semi-ripe cuttings in summer with bottom heat; slow, and seed-grown plants take many years to fruit.

A cutting taken in PlantParlour keeps its link to the plant it came from, so a propagation years later still traces back to the mother plant — which is the point if you ever sell or trade it.

Toxicity and safety

Mildly toxic to cats and dogs — the essential oils in the leaves and peel cause vomiting and, in cats, can irritate skin.

The ASPCA does not list Citrus microcarpa itself, but lists a relative, Calamondin Orange (Citrus mitis), as toxic to cats and dogs (checked 26 October 2026).

If your pet has eaten a plant, call your vet, the ASPCA Animal Poison Control Center on (888) 426-4435, or the Pet Poison Helpline on (855) 764-7661. Both are open around the clock and may charge a consultation fee. Take the plant or its label with you.

This is general information, not veterinary advice. We don't test plants: what we say about toxicity follows the ASPCA's published plant list as it stood on 26 October 2026, and that list can change. "Non-toxic" means not poisonous — a pet that eats enough of any plant can still vomit, and fertiliser, pesticide or leaf shine on a plant can harm it. It also only helps if the plant is what you think it is. It covers cats and dogs only; ask your vet about rabbits, birds, reptiles or anything else, and a doctor about children. Read our terms.

Every houseplant in the library the ASPCA lists as non-toxic to cats and dogs

Questions people ask

How often should you water a Calamondin?

Water every 6 days as a starting point — that is the cadence PlantParlour sets for Citrus microcarpa. Water thoroughly when the top few centimetres are dry, with rainwater if your tap is hard. Never let it stand in a saucer. Light, pot size and the time of year all move that number, so treat it as a reminder to go and check rather than a rule.

How much light does a Calamondin need?

As much direct sun as possible, and outdoors from late spring to autumn if you can manage it. Citrus indoors in poor light drop their leaves and never fruit.

Is Calamondin toxic to cats and dogs?

Mildly toxic to cats and dogs — the essential oils in the leaves and peel cause vomiting and, in cats, can irritate skin. The ASPCA does not list Citrus microcarpa itself, but lists a relative, Calamondin Orange (Citrus mitis), as toxic to cats and dogs (checked 26 October 2026). If a pet has eaten part of a plant, call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 straight away.

How do you propagate a Calamondin?