Colourful citrus for cold gardens

Published Jun 24, 2014

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Johannesburg - Lemons and oranges are two of the most popular citrus fruits, and apart from their health properties, they are desirable landscaping plants with year-round attractive form, glossy evergreen foliage, fragrant blossom and decorative fruit in season.

They can be grown as a feature in a lawn or in a border, but will need the same fertilising and spraying as citrus grown in an orchard. The most important requirement for growing citrus is excellent drainage. Where soil is poorly drained, citrus should be planted in a raised bed with compost and coarse sand.

Citrus trees can be trimmed into a desired shape, but if the lower branches are removed, the trunk should be protected from sunburn by painting it with one part water-soluble paint mixed with four parts water. An alternative is to wrap newspaper or hessian around the trunk, making sure the ties are loosened as the trunk expands.

Citrus roots extend beyond the branch ends, so mulching this area is beneficial, as it retains moisture in the soil. Citrus does not like continuous disturbance around its roots, so grow a permanent ground-cover such as plectranthus, bergenia or variegated lamium.

Some growers recommend feeding citrus regularly in small amounts from late winter through to autumn, alternately, use a high nitrogen fertiliser three times a year.

Fertilise with a balanced fertiliser such as 3:1:5 or 8:1:5 in July, December and March. The nitrogen content will promote leaf growth and the potassium promotes fruit production. Start by giving a mature tree about 1kg of fertiliser over a year, and then gradually increase the amount until the tree is getting 7.5kg a year. In addition, give the tree 75g of Epsom salts three times a year. Spread a mulch layer of compost and then spread the fertiliser around the trunk, going as far out as the drip line of the branches. Water well after application.

Varieties

The variety of citrus you grow will depend on the climate, as some citrus are more cold hardy than others. Lime trees require the most heat, followed by lemon.

There are several varieties of lime, each with its own flavour; the lemmetjie is sugary and sweet, while “Tahiti” bears large, almost seedless fruit. The West Indian lime is grown for its juice and for preserving.

Lemon trees are among the most useful trees and were grown in most old Joburg gardens. Early rough-skinned varieties, such as “Cape Rough” were valued for their rind and juice for cooldrinks, for flavouring desserts and fish dishes, and for preserves. The earliest variety in South Africa, they were thought to have arrived 400 years ago from St Helena Island.

Modern varieties, such as the compact “Meyer” or taller-growing “Eureka”, have the advantage of bearing juicy, smooth-skinned fruit most of the year. Both varieties are ideal for lemon juice.

Follow these instructions on how to make a fabulous, concentrated, home-made lemon juice:

* Place equal amounts of lemon juice and sugar in a saucepan and heat to just below boiling point. Don’t allow the mixture to boil.

* Stir until the sugar melts and then allow to cool.

* Dilute the lemon syrup with iced water to your personal preference.

If you have a sick lemon tree, dose the tree with the following:

* 1kg 2:3:2 (22) fertiliser

* 1kg magnesium sulphate (Epsom salts)

* 1/2kg urea

* 1/2kg potassium sulphate

* 1tbs manganese sulphate

* 1tbs zinc oxide

 

The two most popular garden varieties of orange are the juicy, almost seedless “Washington Navel” and the smaller “Valencia” with thinner rind. “Seville” oranges are grown for making marmalade.

Mandarins, tangerines and naartjies are all interrelated, and there are some interesting crosses – “naraja”, a cross between naartjie and orange, and “mineola”, a naartjie crossed with a grapefruit.

Space in the garden is the deciding factor as to whether to grow citrus in standard or dwarf form. In small gardens, citrus that has been grafted onto dwarf rootstock is best.

Calamondin has fruit-like tiny oranges and is very decorative when grown in a container.

Their primary use is ornamental, as the fruit is sour, although the skin and flesh are good in marmalades.

 

GENERAL GARDENING TIPS

* Water the garden early in the day, as water left on leaves can freeze on cold nights.

* Pansies and violas love the cold. There is still time to plant out seedlings to fill gaps. Lobelia, viola, pansy, nemesia and dianthus establish quickly. Seedlings that are already flowering in the trays are tempting, but the quality of the plant is also important. Healthy seedlings will have sturdy green leaves. Cut off faded flowers on annuals to encourage continuous flowering, and remove side shoots and unnecessary tendrils from sweet peas.

* Feed winter-flowering bulbs and annuals with the appropriate fertiliser. Include plants in containers in your regular watering and feeding routine. Remove any weeds as soon as they appear in the garden and in pots, as they absorb nutrients and water needed by plants. Give containers a fresh look with paint in a colour that pleases you.

* Spring is only six weeks away. The sap in plants will begins to rise and buds will soon can be seen on spring flowering azalea, rhododendron, camellia, magnolia, mock orange (philadelphus), deutzia and viburnum. They will need regular watering or their buds may abort. Remove dust and grime on statues and garden ornaments in shrubberies using soapy water and a cloth.

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