The most fashionable citrus at the moment is the lime. Demand for varieties like Tahitian and Kaffir has built up tremendously over the last few years, probably because they are so popular in Asian cooking. Limes are an excellent source of Vitamin C and they are a great substitute for lemons. They can be used for drinks, seafood dishes, chicken, meats, desserts, cakes, biscuits and marmalade.
Tahitian lime (Citrus aurantifolia)
This variety produces very juicy fruit all year round. The plants grow to around 3x3m (10×10′) tall, and they do well in the garden or in pots. The seedless fruit is small and green when ripe, although it can be left on the tree until it turns yellow. Tahitian limes are easy to grow. They are reasonably frost tolerant, but in very cold areas you should wait until spring before you plant.
Kaffir lime (Citrus hystrix)
Kaffir limes will reach 1.5 metres (5′) tall, but because the leaves are constantly being picked for cooking, the plants usually remain small in size. They also make good pot specimens. The leaves of the Kaffir lime are an essential ingredient of many Thai recipes, including green curries, fish dishes and soups. The flesh of the fruit is usually thrown away, but the rind and zest is sometimes used. Each leaf is ‘waisted’, and looks like two leaves joined together.
Australian finger lime (Citrus australasica ‘Rainforest Pearl’)
Formerly known as Microcitrus australasica, the Australian finger lime grows from 3-10m (10-33′) tall. It is a hardy, spiny, shrub or small tree which is closely related to the domestic citrus. The fruit is long and narrow, and is a brownish red colour. It has a sour taste and is probably best used for Thai cooking, jams, garnishes, sauces and drinks. If possible, before you buy an Australian lime, taste the fruit to see if you like the flavour.
Best climate: Limes grow well in the warmer areas of Australia. Worth a try in cooler zones, but protect from frost when young.
Citrus care: A position in full sun is best. Keep trees well watered when the fruit is forming in spring and early summer. Trees growing in the ground should be fertilised in August and February. Complete Citrus Food alternating with Dynamic Lifter would be suitable. Feed citrus growing in pots every six to eight weeks. Once again alternate Complete Citrus Food with Dynamic Lifter, or use 3-4 month Osmocote applied in spring and early summer. Feed Australian finger limes with an organic fertiliser in late winter and spring. Water well before and after fertilising. Keep the area beneath your trees free of grass and weeds. Mulch with compost or other organic material, but make sure that the mulch does not touch the trunk of the tree.
Getting started: Tahitian and Kaffir limes are available from nurseries. They cost around $15-$25 for 200mm (8″) pots, and $25-$30 for 250mm (10″) pots, or 15 litre bags. Expect to pay around $25-$30 for Australian finger limes in 5 litre bags. These will probably be more difficult to find, and it may be necessary to order one from your local nursery.
Our segment was filmed at Engall’s Nursery, 997 Old Northern Road, Dural, NSW. Phone: (02) 9651 2735.