Skills books › Growing Fruit Trees in South Africa

How to grow citrus trees at home in South Africa

Citrus wants sun, shelter, soil that drains, steady water and feeding little and often. Give it those and it bears for decades with almost no pruning. Most problems in home gardens come from irregular watering, poor drainage, or a tree from an unknown source.

Which citrus?

• Naartjies: easy to peel, ripening from autumn to winter.
• Oranges: navels for eating in early winter, Valencias for juice in late winter and spring.
• Lemons: bear most of the year. One tree serves a household.
• Limes: the most frost-tender. Best in warm areas or in pots.
• Grapefruit: need long, hot summers to sweeten.
• Kumquats: small, hardy and good in pots.

A full-size orange grows four to six metres tall and wide. Dwarf citrus stays at about two to three metres. An early naartjie, a navel orange and a lemon together give fruit for much of the year. One tree bears on its own, without a partner.

Climate and frost

Citrus grows almost everywhere in South Africa except the coldest places. From most to least frost-tender: limes, lemons, grapefruit, oranges, naartjies, kumquats.

On the Highveld and in other frosty areas, plant in the warmest spot, against a north-facing wall, and protect young trees for their first two or three winters.

• Cover the tree on frosty nights with frost cloth held off the leaves and reaching the ground. Remove it in the morning.
• Water the day before a frost. Moist soil holds more warmth.
• Do not feed after late summer.
• If frost burns the leaves, wait until spring before you prune.

Water

Citrus has shallow feeding roots and keeps its leaves all year, so it needs steady water.

• Water deeply and regularly, more when the tree is flowering and setting fruit and in heat waves.
• Mulch the root zone, keeping the mulch a hand's width from the trunk.
• Never let the soil stay waterlogged. Citrus rots in wet soil.
• Irregular watering, dry and then soaked, splits the fruit and makes the tree drop it.

Feeding

Feed little and often with a citrus fertiliser that includes trace elements, spread over the root zone and watered in:

• in late winter, as growth starts;
• in early summer, after the fruit has set;
• in late summer, but not after about February in frosty areas.

Add a layer of compost under the mulch once a year.

Fruit problems explained

• Small fruit dropping: normal. The tree sets far more than it can carry and thins itself after flowering and again in early summer.
• A huge crop one year and little the next: thin the young fruit in the heavy year, and pick on time.
• Green but ripe: in warm areas, the skin stays green because the nights are warm. Taste, not colour, tells you that citrus is ripe.
• Dry, puffy fruit: left on the tree too long.

Citrus does not ripen further after picking, so pick it when it tastes sweet.

Pruning

Citrus needs little pruning. After harvest, remove dead and crossing wood, strong upright water shoots, and any shoots from below the graft. Trim the lowest branches to 30 to 50 cm above the ground. This keeps fruit off the soil and stops ants from climbing straight in.

Pests

Ants farm aphids, scale and mealybugs for their honeydew and protect them. Keeping ants off the tree often lets natural enemies clear the pests.

Citrus greening is a serious disease spread by an insect, the citrus psylla. Leaves show blotchy yellowing that does not match on the two halves of the leaf. Only a laboratory test confirms it, so ask a registered nursery or an extension officer. Buy only certified citrus trees.

This guide is based on Chapter 6 of Growing Fruit Trees in South Africa.