How to grow Longan in Australia

Where to plant

Longan wants full sun, a warm, frost-free spot and deep, well-drained soil with a pH of about 5.5 to 7. It tolerates drought once established and is fairly wind resistant, but it does not tolerate waterlogged or flooded soil, or salty soil and salt wind.

Flowering is the tricky part. Longan blooms well after a long, cool, dry winter without frost, and blooms poorly after a warm winter. That makes the subtropics, with mild winters, good longan country, while crops in the hot lowland tropics can be irregular. Young trees can be killed at about minus 2 to minus 3°C; mature trees tolerate brief light frosts.

• South East Queensland and the Northern Rivers: plant from September to February in a warm, frost-free, sheltered spot.
• North Queensland: plant from September to March. Longan has been grown in north Queensland since the mid 1800s. Crops are most reliable where winters are cool and dry.
• Darwin: plant from September to March. The tree grows well, but flowering can be irregular after warm winters.
• Sydney: marginal. Only in warm, sheltered coastal spots, planted from October to January.
• Melbourne, Adelaide, Perth, Canberra and Hobart: our calendar marks these as unsuitable.

Choosing a variety

Buy a grafted or marcotted (air-layered) tree of a named variety; seedlings are slow and unreliable. Kohala is the most widely grown variety in Florida and gives large, sweet fruit. Biew Kiew is a Thai variety that is sold in Australia. Reliable bearing is the main challenge with longan worldwide, so ask a local nursery which variety crops best in your district.

How to plant

1. Plant in the warm months in frost-free weather.
2. Choose a sunny spot with deep, well-drained soil, sheltered from salt wind.
3. Plant at the same depth as in the pot, water in deeply and mulch widely, keeping the mulch clear of the trunk.
4. Water young trees regularly and deeply until established.
5. Space trees about 7 to 8 m apart, or less if you will prune hard to keep them small.

Watering and feeding

Water young trees regularly. Established trees tolerate drought, and a drier spell over winter helps bring on flowering. Once flowering starts, keep the soil moist through flowering and fruit development. Too much rain during flowering reduces flower opening and bee activity.

Feed through the growing season with a balanced fertiliser, and mulch to hold moisture and keep the soil temperature even.

Pruning and care through the year

• Prune young trees to build a strong, open framework, and prune after harvest to keep the tree to a height you can net and pick. Pruning also increases the bearing surface.
• Bees are the main pollinators, visiting the flowers in the morning, so avoid sprays that harm them during flowering.
• Net trees or bag fruit panicles as the fruit ripens to protect it from birds, flying foxes and fruit fly.

Harvesting

Longan fruit ripens in late summer, about January to March in Australia. Fruit does not ripen further once picked, so taste one before harvesting the whole bunch: ripe fruit is sweet, with a tan to light brown skin. Cut whole bunches with secateurs.

Fresh longan keeps for a week or two in the fridge. Peel the thin, leathery skin by squeezing the fruit, and eat the flesh fresh, or dry or freeze it.

Growing in pots

Longan is a large tree and is best in the ground. A dwarf or compact selection can be grown for some years in a very large pot, at least 60 cm wide, with free-draining mix, but crops will be small.