These trees are an asset in a garden with evergreen foliage, fragrant blossoms and decorative edible fruits
Throughout the year, citrus trees are an attractive feature in the garden. They are evergreen (some have variegated foliage) and produce scented blossoms in spring, followed in winter with colourful fruit rich in vitamin C.
Some varieties, such as the Meyer lemon, produce blossoms and fruit almost all year round. Citrus that have been grafted on dwarf root stock are well suited to growing in large containers on patios and for adding a touch of the Mediterranean to courtyards.
In the temperate regions of South Africa we are able to grow a variety of citrus outdoors: oranges from China and south Vietnam, lemons from south-east Asia, mandarins from Japan, limes from India and south-east Asia, and grapefruit, a West Indian hybrid.
The variety of citrus you grow will depend on the climate and local conditions. Choose a sheltered spot in windy gardens. Your local garden centre will advise you which citrus are suitable for your garden.
Lemons that are native to south-east Asia are among the most useful of the citrus family. They are used for flavouring food and drinks, for preserves, and in soaps, detergents and the perfume industry.
The thorny “Cape” or rough-skinned lemon is valued for the rind and juice.
Cultivars that flower more than once a year, such as the compact, almost thornless “Meyer” with thin rind, and the taller growing “Eureka” and “Genoa”, produce juicy, smooth skinned fruit most of the year.
Lime trees are only suitable for frost-free conditions. Their acid fruit is grown for juice, preserves and garnishes. Leaves of the Thai lime are used in cooking.
The first oranges were so bitter, they were almost inedible. The Portuguese were responsible for introducing superior varieties from China to Europe and then to Brazil. These are the oranges from which today’s superior cultivars have been bred.
The juicy, almost seedless “Navel” orange has early, mid and late season varieties. “Valencia” has smaller sweet fruit with thinner rind and no navel. “Seville” oranges are sour and used for making marmalade.
Mandarins, tangerines, tangelos and naartjies
These are all inter-related and have delicious fruit and juice. Tangelo is a tangerine crossed with a grapefruit.
Calamondins and kumquats
They are ideal for large pots in a courtyard or on a patio and are grown primarily for their ornamental value. Their miniature fruit is used in preserves.
Citrus for containers
Space in the garden is the deciding factor as to whether to grow citrus in standard or dwarf form or in containers.
In small gardens, citrus that has been grafted onto dwarf rootstock is best. If you have brak soil, growing citrus in large pots is recommended.
The most important requirements for growing citrus are full sun, excellent drainage and regular watering. Plant at the correct depth in composted soil. Fertiliser should be given only when the tree shows signs of new growth.
Citrus have shallow roots that extend beyond the branch ends. They do not like continuous disturbance around their roots, so mulching this area with bark chips or a ground cover is beneficial. Leave space around the trunk area to avoid disease.
A citrus tree in the garden will need the same fertilising as citrus grown in an orchard. Some growers recommend feeding citrus regularly in small amounts from late winter through to autumn. Others prefer a high nitrogen fertiliser three times a year – in July, December and March. The amount given should be relative to the size of the tree – about 300g for young trees, increasing the amount as the tree matures. Spread 75g of Epsom salts to the drip line of the branches three times a year. Always water well after fertilising.
It is natural for some blossoms and tiny fruit to fall. Limes are picked green, but most citrus fruit becomes sweeter if allowed to ripen on the tree. After fruiting, trees can be given a light pruning. Leave four to six branches that grow laterally and are referred to as “scaffold” branches. Remove crossed branches to allow in sunlight and for air movement. Remove any suckers.
Citrus psylla is a swelling on the upper surface of the leaves caused by sap-sucking bugs. Spray with Bioneem, Ludwig’s Insect Spray or Margaret Roberts Organic Insecticide.
Aphids produce a secretion known as honeydew, which in turn attracts ants. Spray with Oleum according to directions on the container.
Collect and destroy any fruit that has dropped to the ground to prevent fruit flies breeding. Do not add to compost heaps.