Scurvy, Captain Cook and Citrus
Us Aussies love our citrus. From a zesty lemon delicious pudding as part of a family dinner to a slice of orange in our Aperol spritz, we adore a citrus tang. So it makes sense that citrus trees are found on gardens across the country.
Although Australia has a number of native citrus plants (such as the increasingly fashionable finger lime), most of the varieties that grace our fruit bowls are imported. But do you know how the limes that grow so prolifically in so many backyards first came to these shores?
Captain James Cook pioneered the use of limes to fight scurvy – ‘the plague of the sea’. Limes were part of the diet given to his seamen to prevent them from getting the awful disease and his ship restocked on limes at Rio de Janeiro, where they’d been cultivated by Portuguese merchants for some time. These Brazilian limes had probably been brought over by Portuguese explorers who had travelled in the Far East and South East Asia. The Chinese had already been growing citrus for hundreds of years.
Incidentally, we call a small, orange citrus a ‘mandarin’ which means Chinese apple – the origins of the fruit are there in the name. And the American nickname for the British – ‘Limeys’ -comes from the lime ration given to British sailors.
Apart from their great flavours, another reason that limes, oranges and lemons are so popular is that they keep really well. In fact, they can be stored for years and still taste great. This was a huge bonus on long sea voyages.
These days we know that it is the high levels of vitamin C (ascorbic acid) in citrus that slowed the ravages of scurvy. It has also made it a much-loved fruit drink in winter when many of us are fighting colds.
The Cultivation of Citrus
Thanks to the development of orange juice concentrate, the fruit juice can be drunk both here and overseas all year round.
In Australia, we have so many growing regions and such a range of orange varieties that we rarely have a gap in the calendar when we can’t get fresh Australian oranges shipped in from one state or territory or another.
Citrus trees, from the family Rutaceae, includes some of our most hardy cultivated plants.Globally there are over 1800 species in 150 genera found mostly in the tropics, sub tropical and temperate areas of the southern hemisphere. Here is Australia we have about 320 species in 41 genera, many of which aren’t so obviously related to the orange as the mandarin is to the tangerine. Examples include the Correa or ‘Native Fuchsia’ and the ‘Brown Boronia’ which may not look like citrus plant, but the scent released when you crush their leaves indicates they are distant cousins of oranges.
Citrus shrubs hold a special place in traditional Chinese culture and were grown in the Imperial Palace gardens more than a thousand years ago. The Chinese words for orange and tangerine are similar to those for success and luck and their colour is a reminder of gold. Having lived in Hong Kong for a while, I know firsthand that as Chinese New Year approaches, doorways all over the city fill with pots of mandarin oranges, which are believed to bring good luck. If you’d like to know more about Chinese culture and oranges, see here.
In the 2019/20 season, Australia produced more than 500,000 million tonnes of commercial oranges alone – many of them for the juice industry. We have no figures on the quantities of oranges, grapefruits and lemons grown in gardens, but given how many of us have a lemon tree churning out fruit in our backyards, domestic production must be high impressive too.
Interestingly, the US and Brazil dominate commercial production globally, but aren’t big on growing fruit at home.
One area which has started to gain ground in recent years is the manufacturing of essential oils from the skins – especially with orange skins being such an abundant by-product of the juice industry. Even though many cooks love to great orange or lemon zest into dishes, these essential oils are still generally used pretty sparingly. There are times when citrus is a vital part of a recipe – like kaffir (makrut) lime limes in Thai Tom Yom Soup and the half-moon of lemon in a gin and tonic. And then there’s the age-old remedies for colds and the ‘flu which invariably include the juice (and sometimes zest) of a lemon or 2.
Citrus – Mainstay of the Aussie Backyard
For many of us, when our citrus trees are in season, the fruit is so plentiful that it’s a struggle to use it all. My lemon tree has been so fertile this year that I have gifted jars of preserved lemons and plates of lemon slice biscuits to friends and acquaintances. And I’m not alone. On my short walk up to the local shops I’ll come across at least 3 baskets at the end of driveways, piled high with home-grown citrus produce, and a request that passersby, ‘Help Yourselves.’
And if you’d like some more specialised information on common Australian lemon varieties, see here.
Citrus thrive all over Australia from the tropics to the desert. They seem happy in both the clean air of the country and the pollution of our big cities suburbs.
They can have their tricky moments and can be quite demanding as young plants. However, when they mature many gardeners will boast that they never do a thing to their lemon tree and it produces loads of fruit every year. That may well be true once the plant is established, but things can be a bit touch and go until that point!
These guidelines are not meant to be a Bible for commercial growers who have very different requirements and a host of specialised resources at their disposal.
These articles are written for the home gardener.