Oranges

The orange (Citrus x sinensis) is a very popular backyard citrus tree for gardens. It is not only a good-looking tree with its green foliage and sweet-smelling orange blossom, but it also rewards you with juicy, tasty fruit.

Like most citrus, oranges can also be grown in the garden or a large container. In a sunny garden, the trees grow 2.5-5m high and wide. For a large container, sunny courtyard, or small garden, select an orange grafted on dwarf rootstock.

These evergreen trees can be planted at any time of the year, but avoid extremely hot or cold conditions. To reduce transplant stress, water with Seasol at planting. Continue to apply Seasol fortnightly for healthy, strong growth.

Visit your local hardware or garden centre for a variety to suit your garden or pot. Here are a few to consider

• Washington Navel supplies seedless tasty oranges in mid-winter. It is a small to medium tree (3 to 4 metres) with glossy green leaves and small scented white flowers.
• Valencia named after Valencia in Spain, is a top performer with a large yield of sweet tasty fruit. It is a small compact tree with rich green foliage all year round.
• Seville is slightly more cold-tolerant than most orange varieties. Its fruit is bitter and sour to taste and is often used for marmalade. Growing 5 to 7 metres, it has larger, dark, green leaves.
• Blood oranges have a neat compact growing habit and are ideal for a pot or in a food garden. They have red-tinged flesh and skin and produce red juice.
• Dwarf Valencia and Washington Navel are available for larger containers, growing to around 2m. For sweeter fruit, leave the fruit longer on the tree.

Fruit ripens from mid-autumn to spring and can be harvested as needed. It is safe to leave fruit hanging on the tree until it is harvested. Growing two different varieties extends cropping for months.

Oranges are eaten fresh, or juiced, are the basis for delicious cakes (such as gluten-free orange and almond cake), and of course, are finely sliced to make marmalade. The rind can also be candied.

Growing conditions

Aspect Orange trees need a bright, sunny location with sun from the morning onwards. They can tolerate a little afternoon shade, especially in hot climates. Protection from cold conditions is vital.

Soil They grow in a wide range of soils but require excellent drainage. In areas with poor drainage, grow in raised garden beds (raised at least 30cm) or in large containers. In containers, use a good quality, free-draining potting mix such as Seasol Advanced Potting Mix. Before planting into the ground add homemade compost and organic matter and/or Seasol Super Compost.

Climate Although oranges are subtropical plants, they grow in temperate frost-free climates. In cold areas, they need complete protection from cold winds and frosts, especially over winter. Plant them in a pot or in the ground close to a north-facing brick wall. In a pot move them around the garden to catch the sun. Washington navel and blood orange are more tolerant of cold conditions.

General care

Watering Adequate, even and regular water is critical for fruit formation and development. Lack of water can lead to loss of flowers or fruit. Deep water at least weekly especially when plants are in new growth, flowering or good fruit formation. Water more frequently if plants are in hot, dry or exposed conditions or if they are growing in containers. However, overwatering after the fruit reaches maturity can lead to fruit splitting.

Feeding and mulching Oranges are heavy feeders. Feed every season with a complete fertiliser, especially for citrus like Seasol plus Nutrients Fruit & Citrus. Supplement feeding with a liquid fertiliser, such as PowerFeed PRO SERIES for Fruit & Citrus every two to four weeks. Plants in containers can be liquid fed regularly every two to four weeks while they are growing, flowering and fruiting using PowerFeed PRO SERIES Fruit & Citrus.

Pruning Oranges produce fruit without regular pruning however it is necessary to remove dead wood or congested branches. Older trees can be renovated by hard pruning in spring (avoid pruning in summer as the bare branches can be sunburnt).

Watch out

• Pests The main pests that attack mandarins include aphids on new growth, scale on leaves and stems, and citrus leaf miners which cause silvery trails in new growth. Use an organic pesticide such as EarthCare White Oil insect spray to treat these pests.
• Bugs These include spined citrus bugs and bronze orange bugs that attack developing fruit. These pests can be treated with an organic oil such as EarthCare White Oil insect spray. Spray for bugs in winter when they are likely to be present in immature stages (known as nymphs). Adult bugs often infest trees in large numbers, especially in summer. They can be removed by hand (wear gloves) and drowned in a bucket of soapy water. Always take extreme care around these pests as they can eject a defensive spray of liquid that may damage eyes or skin (also keep pets away from stink bugs).
• Fruit fly In fruit fly zones, oranges may also be attacked as they ripen by fruit fly. Protect crops with splash baits.
• Fruit production Oranges can be heavy bearers every second year with much reduced crops in the intervening years. Thinning fruit in heavy cropping years can reduce the effect of biennial bearing.
• Tree establishment Oranges put more energy into flowering than growing in the first two years. Remove flowers for the first two years so the tree can put all its energy into healthy strong growth and tree establishment.
• Dry tasteless Orange fruit are likely to be dry due to earlier than usual fruit development and lack of regular fertiliser, water and sunlight during this time. Reduce the likelihood of dry fruit by regular deep watering and feeding the tree during all stages of development from plant growth to flowering and fruiting as above.
• Fruit Colour While oranges turn from green to shades of yellow and orange as they ripen, the skin of ripe oranges can return to green. This is a natural phenomenon to protect the fruit from sun damage. The fruit is still ripe and ready to eat.
• Split fruit Split fruit (caused by overwatering or heavy rain late in ripening) can lead to rotting fruit. Damaged fruit may also attract vinegar flies. Remove split fruit from the tree.