Australia plant library · fruit

Mandarin

Citrus reticulata (e.g. 'Imperial') · Rutaceae

Easy-peel fruit on compact trees.

Photo: Joe Ravi, CC BY-SA 3.0, via Wikimedia Commons

Sun: Full sun.
Soil: Fertile and very well-drained.
Soil pH: Slightly acidic to neutral, about 6.0-7.5, as for citrus generally.
Water: Deep watering once or twice a week; keep up the water while fruit matures (otherwise fruit is dry and pithy).
Hardiness: Subtropical and temperate; among the more cold-tolerant citrus (to about -6 C). Protect trees under 3 years old from frost.
Height and spread: About 2-5 m depending on variety and rootstock; dwarf forms for pots.

Guv's tipKeep the water up to mandarins while the fruit matures, or it'll be dry and pithy. And never compost fruit-fly infested fruit.

Through the year

When to plant

Autumn (Mar-May) in frost-free areas; spring (Sep-Nov) where frosts occur.

Harvest or flowering

Apr-Aug depending on variety ('Imperial' is earliest, from April).

Pruning

Light. Shape after harvest and remove dead or crossing wood. 'Imperial' tends to bear in alternate years (biennial bearing).

Making more plants

Grafted onto rootstock (e.g. Carrizo citrange).

Watch out for

Pest

Queensland fruit fly

Look for: Sting marks; maggots inside ripening fruit; rots; fruit drop.

What to do: Monitor with traps; use protein bait sprays or male-lure traps and exclusion netting or bags. Bag and solarise, or freeze, infested fruit - never compost it.

Pest

Citrus gall wasp

Look for: Woody galls on shoots.

What to do: Prune out galls before adults emerge in spring.

Pest

Scale insects and aphids

Look for: Sap-suckers with honeydew and sooty mould.

What to do: Horticultural oil or a registered pyrethrum spray.

Disease

Phytophthora root/collar rot

Phytophthora spp.

Look for: Gummosis; dieback in wet soils.

What to do: Improve drainage and keep mulch off the trunk.

Always read and follow the label on any treatment, and check it is approved for use where you live.

Safety and spread

Pets and people: Citrus is generally toxic to dogs, cats and horses (essential oils, psoralens); the ASPCA lists orange and lemon. Treat mandarin the same.

Weed risk: Not a declared weed in Victoria or Queensland.

Checked against two or more reputable gardening sources. How we check our facts

Keep it by the back door

The Plant Doctor and the Guv's book

Printable pest and disease charts with real photographs, and all 50 Australia plants in one book.

Buy in the shop See all the guides