Sumo Mandarin (Dekopon) | Mandarins.com.au

Sumo mandarin is the largest mandarin sold in Australia and one of the most distinctive. Known internationally as Dekopon, it has a bumpy skin and a characteristic topknot at the stem end. It is seedless, sweet, and easy to peel. The season is short: typically three to four weeks in SA and a few weeks longer nationally. Sumo is sold at Woolworths under the Sumo Citrus brand.

At a glance

Season: Late July to early September
Peel: Bumpy, loose, pale orange with a prominent topknot. Very easy to peel
Seeds: Seedless
Flavour: Intensely sweet, low acid, very juicy. Complex mandarin-orange aroma
Size: Large to extra large (comparable to a small grapefruit)
Best for: Fresh eating, gifting, novelty fruit plates, juicing

Season in Australia

Sumo is one of the shortest-season mandarins available. The South Australian Produce Market noted in July 2025 that Sumo has “only around 3 weeks of availability” in South Australia. Woolworths lists the Sumo Citrus season from August to September nationally.

Andrew Harty of Citrus Australia has recommended looking for Sumo sold under the Sumo brand between late July and early September. Seasonal availability can be difficult to predict: it depends on a small number of licensed Australian growers and on seasonal conditions.

Flavour, peel, and seeds

Sumo is one of the most intensely sweet citrus fruits available in Australia. David Karp, writing in the Los Angeles Times in 2011, described Dekopon as “the most delicious citrus he had tasted” from more than 1,000 types tasted, citing “firm flesh that melts in the mouth, an intense sweetness balanced by refreshing acidity and a complex, lingering mandarin orange aroma.”

The peel is bumpy and loose, pulling away from the flesh easily. The topknot at the stem end is a trademark feature and makes the fruit immediately recognisable in a mixed display. Despite the unusual appearance, the eating experience is clean and convenient.

Seeds are absent in commercially grown Australian Sumo. This is partly a product of the variety itself and partly a function of orchard management.

Where it is grown

Australian Sumo production is concentrated in the Riverina district of New South Wales, primarily around Leeton. Pacific Fresh, based in Leeton, was one of the first Australian operations to hold plant breeders rights for the variety and supply it commercially. The SA Produce Market sources its Sumo from Riverland-adjacent growing regions.

Bundaberg Brewed Drinks added an Australian-grown Dekopon Mandarin flavour to its craft range in early 2026, using fruit from Australian suppliers and describing the variety as “Sumo citrus.”

Origin and history

Sumo mandarin is sold under its Japanese name Dekopon in Japan, where it was developed in 1972 by crossing a Satsuma mandarin with a Kiyomi tangor (itself an orange-mandarin cross). The cultivar is also known as Shiranui. It became a premium gift fruit in Japan before being introduced commercially to California (where the Sumo brand was established) and subsequently to Australia.

The variety entered Australia through licensed growing agreements. Trees and propagation material are controlled by plant breeders rights, which is why Australian production remains limited to a small number of growers. Home garden trees labelled Shiranui are available from specialist nurseries such as Engalls in Sydney, and the variety is sometimes also sold under that name.

In Japan, Sumo is so prized it is commonly given as a gift. The SA Produce Market’s seasonal newsletter noted this tradition, describing Sumo as “one of those rare treats that truly deserves the hype.”

Best uses in the kitchen

Sumo is most commonly eaten fresh. Its size and sweetness make it a centrepiece fruit rather than an everyday snack. Peel it at the table and share the segments: the visual contrast of the bumpy exterior and the juicy interior is part of the appeal.

For juicing, Sumo produces a rich, sweet juice with low acidity. It can be blended with lime or lemon to add sharpness.

For cooking, Sumo’s intensity works well in desserts. Use the juice in a mandarin curd or reduce it gently for a glaze over pork or duck. The zest is highly aromatic and suits biscuits and shortbread.

How it compares

Sumo vs Imperial: Sumo is much larger, sweeter, and later. Imperial is more widely available. Sumo is a premium seasonal treat rather than an everyday mandarin.

Sumo vs Honey Murcott: Both are sweet, but Sumo is seedless and easier to peel. Honey Murcott has a more complex acid balance; Sumo is more uniformly sweet and low in acid.

Sumo vs Afourer: Afourer is smaller and more reliably available. Sumo has the edge on size and sweetness, but costs more and has a shorter season.

Buying and storing

Look for Sumo Citrus at Woolworths in August and September. Independent greengrocers may also carry it under the Sumo or Dekopon name. Availability is limited: once the season ends, it ends.

Choose firm fruit with a loose but intact skin. The topknot should be present and the skin should feel slightly spongy but not shrivelled.

Store at room temperature for up to a week. Refrigerate if keeping longer. The loose peel means it can dry out faster than tight-skinned varieties.

Growing it at home

Shiranui (Dekopon/Sumo) trees are available from specialist nurseries including Engalls in Sydney. The tree grows to 3 to 5 metres and produces fruit from June to July in backyard conditions. Shiranui trees grown in home gardens are not covered by the commercial Sumo brand licence and may be sold as Shiranui.

Grow in full sun with well-drained soil in subtropical or warm temperate zones. The tree has a dense growth habit and can be an attractive feature in a garden or large courtyard.

For growing guides, see best backyard mandarin trees and mandarin tree care.