Growing Australian finger lime: cultivation & care
The unusual shape of its fruits gives the Australian finger lime plant its name. We will show you how to grow finger limes and how to take care of this unique lime tree.
The Australian finger lime tree (Microcitrus australasica) bears elongated, finger-shaped fruits. If you cut open the exotic fruit though, you will find small pellets on the inside that resemble caviar. For that reason, finger lime plants are also referred to as caviar limes. The so-called “lime pearls” are very expensive and not easy to obtain. Therefore, you might be pleased to know that growing finger limes in your own garden or on the balcony is, in fact, possible. In the following, you will find all kinds of information about finger lime care, cultivation and different varieties.
Australian finger lime: origin & characteristics
The botanical name Microcitrus australasica reveals the finger lime plant’s origin. Australia, more specifically the semiarid zones of northern Australia, is the home of the exotic fruit. It is one of the few wild lime varieties that still exist. Australian finger lime trees are part of the genus Microcitrus and belong to the rue family (Rutaceae). They have a lot of rather small leaves that are narrow and needle-shaped on young trees. Older trees have bigger, more oval leaves with rounded tips. The tree axils have short but very spiky thorns. The white flowers are small with four or five petals and four to eight locules (chambers within the ovary of a flower) per ovary. Compared to other lime varieties, the scent of the flowers and fruits is not quite as aromatic. The lime pearls inside the fruit make up for that, though: they have a wonderfully intense and unique aroma.
Australian finger lime: colourful varieties
There are various finger lime varieties with different flesh and peel colours and oblong to spherical fruit shapes. Here, you can find a selection of different varieties of the Australian finger lime:
- ‘Polpa Gallia’: the fruit of the ‘Polpa Gialla’ finger lime has a green peel and yellow flesh.
- ‘Virgata’: the ripe fruits of this variety have a yellow-green peel. They grow in a round shape but have the typical caviar-like flesh.
- ‘Byron Sunrise’: this variety has a chestnut brown peel which turns almost black when fully ripe. The colour of the flesh is orange to red.
- ‘Durham’s Emerald’: the fruits of this finger lime are dark purple to black. The lime pearls are emerald green.
- ‘Jali Red’: this type of finger lime is characterised by light red to pink flesh. The peel is dark green to brown.
- ‘Judy’s Everbearing’: the ripe fruits have a bright pink-coloured peel. The lime pearls are also pink.
- ‘Sunshine Yellow’: as the name suggests, the lime pearls of this variety are yellow. The peel of the fruit is green to yellow.
The biodiversity of finger lime plants is impressive. In addition to the Australian finger lime or caviar lime, there are also many other unique types of citrus fruits.
Buying a finger lime tree
Australian finger lime plants are relatively rare, which makes them expensive and sometimes hard to find. Nevertheless, you should be able to purchase them from well-assorted nurseries and garden centres. There is also a number of online retailers specialising in rare citrus fruits that offer finger lime trees for shipping.
Next, there are some things you should pay attention to when buying your finger lime tree. There should not be any defects, such as broken leaves or damaged bark that are visible to the naked eye. The grafting point – most finger lime varieties are grafted – should be in great condition. Choosing the right variety is also important as the different types of finger limes vary look very different. Lastly, you should check the health of the plant carefully to make sure that the tree is free of pests or diseases.
When buying a finger lime tree, you should pay attention to:
- Health condition of the plant
Finger lime cultivation: choice of location
Cultivation and care are very similar for all citrus plants. There is not a lot you can do wrong, once you have got the hang of one type of citrus fruit. Citrus plants are not winter hardy; therefore, it is best to grow your finger lime in a pot, so that it can be relocated inside once the weather gets cold.
Wild species like the Australian finger lime prefer to spend the summer outside. It doesn’t always have to be a spot in full sunlight, though; a semi-shady location is sufficient. However, the tree should stand freely and should not have to fight for sunlight with other plants. To ensure that all sides of the tree get the same amount of sunlight, you should rotate it every two months. In winter, you should relocate the finger lime tree to the conservatory or into your house. It should be kept in a bright spot at a temperature of 3 to 15 °C.
Location requirements of finger limes at a glance:
- Outside in summer
- Sunny to semi-shady location
- Inside the house in winter
- Temperatures in winter: 3 to 15 °C
Finger lime tree care
The care for Australian finger lime plants is also not very different from that of other lime tree varieties. Due to the finger limes origin being in semi-arid desert regions, it does not require as much water as other types of limes. Nevertheless, you should water your plant regularly to prevent it from drying out. However, finger lime trees are very sensitive to waterlogging. You should therefore avoid it at all costs. During growing season, you can give your plant a boost with a special citrus fertiliser or some organic fertiliser.
Organic fertilisers with predominantly plant-based ingredients and a long-term organic effect, are perfectly suited for the Australian finger lime’s nutrient demand. In winter, you can reduce fertilisation or even stop it completely. Pruning finger limes regularly is not necessary, but dead or diseased plant parts should be removed. If the plant grows too unevenly, pruning is also advised. However, you should only do this during the hibernation period in winter. Finger lime trees should be repotted every two years.
Australian finger lime care in a summary:
- Keep evenly moist
- Avoid waterlogging at all costs
- Fertilise once a week in summer with a citrus fertiliser
- Prune if necessary
- Repot every two years
Using Australian finger lime in the kitchen
The Australian finger lime’s fruits can be enjoyed simply raw. They are also ideal as toppings on various dishes, as a decoration, or as an aromatic addition to drinks. The caviar-like pearls also go very well with fish dishes or on top of sushi. Additionally, it is great as a fruity salad component. The fruits work particularly well in drinks, for example in champagne or mixed into various cocktails. Desserts, such as ice cream or cake, can also be improved with the finger lime pearls.