The ultimate guide to growing citrus

There are countless books, encyclopaedias and a labyrinth of online articles dedicated to citrus and the best ways to take care of them. But don’t let that discourage you. Citrus are relatively easygoing housemates – when you know the basics, that is.

I’ve done my best to synthesise the citrus syllabus and extract the juiciest pieces of advice below to give you some clarity and confidence to get growing your own.

Species and cultivars

Over the years, I’ve seen and tasted countless cultivars and have fallen head over peels for many beautiful fruiting trees. I think they look incredible when full of fruit and, with so many shapes and sizes available, one can be grown in any half sunny garden.

Citrus species include limes, lemons, mandarins, cumquats, oranges, chinottos, native finger limes, grapefruit, pummelos, tangelos and more. These species can have any number of cultivated varieties and hybrids, some of which you can buy to grow at home.

You can even have a lemon crossed with an orange called a “Lemonade” if you’re feeling a little fancy.

I would start by asking what you’d like from your citrus. These groups are based generally on taste and what you gravitate towards in the culinary department.

1. Sour fruits – lemons, limes, calamondin, cumquats, chinotto, citron, Seville orange
2. Sweet fruits – oranges, mandarins, tangelos
3. Large fruits and coloured flesh – grapefruit, blood orange, pummelos
4. Culinary leaves – kaffir lime
5. Native citrus – finger lime, wild lime, Russel River lime, desert lime

Then decide if your space allows for a full-size or a dwarf-size tree (if one has been cultivated).

If you’re planning a new garden consider a few of the above (full size if possible) such as a lemon, lime, mandarin and kaffir lime as your feature trees and then design the garden around them. You could also plant some of the smaller types in large pots such as finger lime, Nagami cumquat or dwarf blood orange.

Propagation by grafting

When you purchase a citrus tree from a nursery, it will have been grafted onto a more favourable citrus rootstock species by a commercial grower.

Grafting uses many techniques but, generally speaking, the aim is to cultivate the same plant so its overall size, fruit type and taste, (as well as its resistance to pests and disease, tolerance of low temperatures, etc) is more predictable.

The grafting process won’t matter much to you, however if you see any thorny looking shoots growing from the base of your citrus, cut them off as this is the rootstock trying to outgrow the fruiting canopy. And be sure to not buy any plants with this already occurring.

Growing

Sun – Your citrus will need at least five hours of sun per day to stay healthy and provide you with a decent amount of quality fruit.

Soil – For pots and large containers use premium potting mix – look for the Australian Standard Premium logo – this mix will hold water and nutrients for longer producing a more healthy and pest/disease resistant plant. Use the same mix if planting in the ground to provide a suitable soil structure for new roots to grow through. Mound up if you have heavy clay soil or consider raised beds so you can overcome drainage issues. Use pea straw or sugar cane mulch as a light cover, but always keep it off the trunk to prevent root and collar rot.

Feeding – Citrus are heavy feeders so add slow release organic plant food, or a specific citrus fertiliser plus liquid feeding when required. Seaweed and/or fish emulsion foliage sprays are good for adding minor nutrients if you can bear the smell.

Watering – Citrus have a shallow fibrous root system that can dry out quickly. In hot weather, potted citrus may need daily water. New trees need water every couple of days to establish a wider reaching root system. Established trees need water mostly when they’re flowering and fruiting – it’s a simple rule; no water, no juice!

Site – A windy site will dry out your tree quickly and frost will do damage. A sheltered, sunny, and warm and protected from frost is an ideal location. Just be sure to keep grass about 40 centimetres from the trunk to prevent root competition.

Pruning

Citrus trees are generally shaped to allow easy picking, to let light and air flow into the centre of the crown and the removal of dead, inward growing or crossing branches is good practice. You can remove most of the fruit from a young tree before planting if it’s heavily laden so it can focus its energy on root development.

Pest and disease

Citrus can fall victim to many types of pests and diseases ranging from cockatoos and possums to tiny mites and moths. Try to identify the problem (Google images is a great tool) and use the appropriate organic solution. We find having Eco Oil and Neem Oil handy can manage many of the common insect garden pests.