Thursday, December 29, 2011

Lemons, Limes & Cumquats

There are an enormous variety of fruits in the citrus family, many not commonly grown by home gardeners, but they grow extremely well in all areas of Australia from the tropics to the cooler, more temperate areas. Not all are used for their juice, but some like the Bergamot Orange Citrus bergamia is only used for its fragrance. It contains a rich essential oil that is the basis of Eau de Cologne. Others like the Buddha’s Hand Citrus Medica is used specifically for its zest in cooking and confectionary.

It is the lemons, limes and cumquats that are most often grown. Lemons are the most popular citrus that is grown in home gardens from the tropical regions to cold areas. The Lisbon Lemon Citrus limon ‘Lisbon’ is a favourite cultivar in a Mediterranean climate for alkaline soils. They are mostly grafted onto the rootstock of a rough lemon, and will give three crops a year, with only a short gap in January/February where the tree won’t have any lemons at all. The blossoms have a very strong fragrance and will frequently be flowering and fruiting at the same time. This variety can’t always be grown in all areas. Meyer Lemon Citrus Limon ‘Meyer’ is easier to grow in the cooler regions and Eureka Lemon Citrus Limon ‘Eureka’ is a better variety for humid areas. Good drainage is essential no matter what region a lemon is grown. Growing them in a raised bed or on a slope can improve an otherwise poorly drained area. After 10 or 15 year the tree may be too high to pick the fruit comfortably, so it is a good practice to keep them pruned to a height where the top of the tree is easy to reach. A Variegated Lisbon Lemon has ornamental foliage and smaller fruit that is not quite as prolific.

The Caffre Lime Citrus hystrix has become the most popular lime in Australia over the last couple of years. It is grown exclusively for the leaf, which is used as flavouring in Thai cooking. The fruits are extremely sour and not edible, but the plant makes an excellent container plant. They are very easy to grow if they are kept trimmed and are fed twice a year in spring and summer with a slow-release fertiliser. The West Indian Lime Citrus aurantifolia is smaller than the Tahitian Lime. It has a fruit with seeds but it has the best lime flavour and is widely grown and consumed in the tropics, whereas the Tahitian lime has smaller, thin-skinned seedless, very juicy fruit. The West Indian Lime is grown here at the edge of its geographical tolerance, so it is grown on a compatible rootstock, which is rough lemon. The Rangpur Lime Citrus x limonia has a large juicy fruit, almost orange with green seeds. This fruit has an interesting aftertaste.

Nagami Cumquat Fortunella margarita can be eaten whole, including the skin, unlike the Calamondin Citrus madurensis, which is incredibly sour and not one that can be eaten fresh. Chinotto Citrus myrtifolia is one of the most ornamental species that has pendulous branches with very glossy leaves, with fruit that turns bright orange when ripe, but also with fruit too sour to be eaten fresh. These are all best grown in a warm protected area. For a colder climate the Limequat Citrus aurantifolia x Fortunella margarita is an ideal hybrid with delicious fruit.

All of these varieties can be grown in containers, but should be given adequate amounts of fertiliser and they will provide tasty fruit as well as being a beautiful decorative feature.

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