Finger lime fruit set, fruit drop – and harvest!

Australian finger lime is a delicious citrus fruit that’s easy to grow as an indoor plant. It’s sometimes difficult to get it to bear fruit and keep them from dropping. But in the end, you’ll get a great harvest!

Read also:

• All about Finger lime
• Finger lime pruning tips

Your first questions are often going to show your eagerness: when will my little tree bear those delicious fruits? Then, dismay – why are they falling off? And finally, the joy of a bountiful harvest!

How long does it take for finger lime to fruit?

After 3 to 5 years, young trees will start bearing flowers. At first, there are heavy losses, so expect massive fruit drop in the first two seasons.

The harvest increases significantly after 2 years of fruit-bearing.

Usually trees are from grafted stock to make sure they grow and bear expected fruits. Grafting tricks the sapling into thinking it’s older than it actually is.

• The most common grafting technique is cleft grafting.
• Citrus finger lime grown from seed takes longer to bear flowers and fruits (4-6 years).
• Fruit from seed-grown plants may not turn out as expected due to cross-pollinating from other citrus trees.
• Not all finger lime varieties produce seeds in their fruits, these are seedless varieties.

Fruit set for Australian finger lime

In the very best conditions, only 60 to 70% of flowers will “set” or start turning into fruits.

Pollination: a requirement for fruit-bearing

Pollination is normally the work of bees and other insects.

• Honeybees, certain types of flies and even predator pests such as beetles all take a part in pollinating flowers. Set up a hive in your garden and an insect hotel to attract them!
• It’s possible to hand-pollinate flowers delicately to trigger fruit formation.

Cross-pollinating with other citrus

The citrus family readily cross-pollinates. This means your finger lime flowers can receive pollen from other citrus species if they’re nearby – provided they produce fertile pollen. Luckily, this is often the case: most citrus varieties, from calamondin to kumquat, aren’t sterile.

• Only a few won’t work, like pollen-less navel and Satsuma orange varieties.
• Any other species should work fine.
• If you’ve got other finger lime varieties blooming at the same time, of course, favor these.

Hand pollinating finger lime

To hand pollinate finger lime, a small paintbrush with soft strands is needed:

• simply swipe the brush delicately around the inside of each flower, one after the other
• you should notice pollen caught in the brush hairs, like yellow dust
• some flowers may be at different stages of maturity, so this may need to be repeated every few days or weekly as new flowers appear
• as mentioned above, if you collect pollen from different trees and/or species, you’ll increase the chance of success.

So now you’re on track to have lots of little fruits appear – how do you make sure they mature? Read on!

Finger lime fruit drop

Microcitrus austalasica often drops many of its fruits at the slightest sign of stress.

Keeping the soil around the tree slightly moist is essential to reduce fruit drop.

• Plant mulch, especially seaweed-based mulch, will do the trick.
• It also breaks down into much-needed nutrients and trace elements.
• Water up to twice a week, especially for finger lime in pots.

It is normal for a certain amount of fruits to drop. Abundance is nature’s way of sharing to other species while still ensuring reproduction. It’s common to see up to half of set fruits start dropping.

• Apart from water stress mentioned just above, a relevant cause of fruit drop is lack of trace elements in soil. This is common in pot-grown finger lime.
• Fertilizing with citrus-specific fertilizer or fermented tea made from weeds can counter these deficiencies, especially if you use comfrey which has deep-reaching roots (trace elements are deeper down in the ground).

Harvesting finger lime

Harvest season is usually November to March. Depending on variety and growing conditions, it can take up to 10 months for a finger lime fruit to ripen.

• Wait for the fruits to easily break off the branch with a light twist or tug.
• They won’t mature when separated from the tree.
• Young trees bear smaller fruits than older ones.
• Better use small, stackable boxes instead of large baskets in order to not crush the delicate fruits.

You will ensure the finger limes mature best by protecting the tree from freezing.

• Winterizing shrubs

An adult tree, properly pruned, can produce up to 45 lbs (or 20 kg) of fruit a year.