Description & Interesting Facts:
Where do finger limes come from?
The Australian finger lime or caviar lime (Citrus australasica) is native to the lowland subtropical and coastal rainforests in the border regions of Queensland and New South Wales. The First Peoples living along the east coast of Australia ate finger limes for thousands of years, and the early settlers also valued the fruit for its high vitamin C content, and did not clear these trees for agriculture.
Because finger limes are endemic to Australia and grow wild nowhere else in the world, they have always been a popular wild fruit for homestead’s there, as they can be used fresh, pickled, made into marmalade, and even the peel can be dried and used as a flavouring spice.
By the mid 1990’s ‘boutique’ marmalades and pickles were sold from wild harvested fruit, and finger limes soon became popularised as a gourmet bushfood because of their burst of tangy flavour, and within 10 years the finger lime was being sold in restaurants around Australia, and was exported fresh.
Like many other citrus, finger limes also have thorns, but their leaves are tiny, and they form intricately branched, prickly shrubs that are more open and less lush in effect than your usual citrus tree. New growth is purple in colour, and in their native habitat they can grow anything from 2 to 7m tall.
Finger Lime Picture courtesy Forest and Kim Starr from flickrFlowering and harvesting times
If grown under optimal conditions finger limes can bloom and produce fruit year round. Their main flowering and fruiting season in South Africa seems to vary according to climate and cultivar. Masses of small, pale pink to white blossoms smother the bushes during their main flowering season, which can be anytime from late summer (February) to autumn (May), and are followed in winter and spring by very slow-growing fruits which only mature later in summer, and even autumn.
The slow growing fruits hang down in small bunches from the branches looking similar in appearance to small cucumbers. The fruits are roughly the size of an average person’s index finger, but fruit from juvenile trees can be less than 2.5cm long.
Finger limes are best harvested when fully ripe and when the fruit simply falls off in your hand with the softest tug.
Finger Lime Cultivars:
In Australia, research on finger limes started in the 1970’s and great progress has been made, resulting in exciting new cultivars which are highly resistant to Phytophthora citrophthora root disease and Citrus greening disease.
Today the Commonwealth Scientific and Industrial Research Organisation (CSIRO), an Australian Government agency which works with leading organisations around the world, and which is responsible for scientific research and its commercial and industrial applications, has developed several hybrids by crossing the finger lime with standard Citrus species.
These hybrids have created many cultivars of finger limes with unique skin colours, and pearl colours in various shades of green, including pale lime-green, pale pink, coral, and scarlet, and each finger lime also has its own distinct flavour.
Finger limes are steadily gaining popularity in South Africa, and several cultivars are now available for garden cultivation.
Finger Lime ‘Pink Champagne’
‘Pink Champagne’ has black to burgundy red skin when fully ripe, and striking pink pearls that taste of sweet lemon with raspberry nodes. It can grow between 1.6 to 3m tall.
Finger Lime ‘Colette’
‘Colette’ features black skin when fully ripe, and bright green pearls with a great balance between sweetness and acidity. It can grow between 1.6 to 3m tall.
In the Kitchen:
The fruit of the Australian finger lime is sought after by top restaurants around the world. The little pearls are fantastic for garnishing cocktails, desserts and canapes, and delicious paired with oysters or salmon, chicken dishes, and in Thai salads.
The taste is a bit different, but you can substitute finger limes for most recipes that call for lime or even ruby grapefruit segments. L like that of a Kumquat, the skin is edible too, and actually has more flavour than the fruit, so you can slice the limes across and use them to make marmalade.
Health Benefits:
Finger limes have been used medicinally by Aboriginal people for thousands of years. They were eaten to ward off disease and the pulp and juice of the fruit was used as an antiseptic by rubbing it onto infected skin sores and boils.
Today we know that finger limes are packed with nutritional benefits. Each fruit contains three times the amount of vitamin C than is present in a mandarin, and it is also a potent source of potassium, folate, and vitamin E. The presence of vitamin E also makes the fruit a powerful antioxidant.
In the Garden:
Finger limes, along with other citrus, make good hedges and espalier well against fences and walls.
It is also an attractive small tree, growing up to 7m and providing a perfect habitat for small birds.
Because finger limes become very dense and spiny with about one thorn set in every leaf axil, they make wonderful barriers to keep animals or intruders away, and if space is limited or you live in a cold winter region, they will thrive in a pot.
Finger Lime 'Pink Champagne' Picture courtesy Molly from flickrCultivation:
In cultivation the finger lime plant is grown in much the same way as other citrus species.
Do you need cross-pollinators for finger lime trees?
The flowers are self-fertile and require no cross-pollination, but as with other self-fertile fruits the trees will often provide a better harvest when cross-pollination occurs.
Are finger limes hardy to cold?
As a tropical rainforest species, finger limes won’t handle heavy frosts, but they will tolerate light frosts. In these regions they can be planted in a warm and sheltered part of the garden. In very cold regions the plants will need to be covered if temperatures drop lower than -5ºC, or they can be planted in a pot which can be covered or moved to a sheltered spot in winter.
Do finger limes grow in coastal gardens?
They do well in coastal gardens if planted in a position sheltered from strong winds.
How much sun do finger limes require?
Although finger limes love warmth and sunshine, they will also do well in semi-shade.
What soil type do finger limes need?
They grow in a wide range of well drained soils with a slightly acidic to neutral pH between 6 and 7.
Plant your finger lime tree at the proper depth
Planting your citrus tree at the proper depth is the most important factor. Plant the tree too low and the trunk will stay wet, and this will encourage bark diseases. Plant it too high and the root ball will dry out too quickly and not enough moisture will get to the tree.
Young trees must be planted in deeply dug, well-drained soil with added compost, but no fertiliser. Newly planted trees should not be fertilised until they start showing new growth.
Provide adequate support for the tree as it grows, and bark mulch is recommended around the plant base to help retain moisture and suppress weed growth. Keep mulch and fertiliser well way from the main stem.
How to feed finger lime trees?
Feed 3 times per year, in July, December and March with a fertiliser for flowering and fruiting plants.
How to water finger lime trees?
During the summer months, established trees growing in the garden can be watered deeply about every 7 to 10 days, and in winter every 2 to 3 weeks. Water well during dry, warm weather, or they may prematurely drop their flowers or developing fruit.
Potted specimens will need to be checked more frequently for watering than those growing in the ground.