Orange Tree

The sweet orange (Citrus sinensis) is a spiny, evergreen tree that grows about 8 to 13 feet (2.5 to 4 m) tall, with fragrant white flowers followed by round orange fruit. It spreads about 3 to 5 feet (1 to 1.5 m) across. Citrus trees are often grown in containers, and many home growers keep them indoors or in a greenhouse in cold areas.

Sowing from seed. Seed can be sown in spring. Seed-grown citrus can be grown, but the size and flavor of the fruit may be inferior. Seedlings also differ from the parent plant, and seed-grown citrus often has long, sharp thorns and can grow very large.

Sow seed in spring, knowing the seedlings will not match the parent fruit. Seed-grown trees are less likely to flower and fruit, and when they do, the fruit is typically inferior.

If you want the same fruit as a named variety, stem cuttings are the most reliable method. Cuttings can be taken in summer. Buying a grafted young tree is another option, since young grafted oranges typically need about 5 years to flower and produce fruit. Larger specimens often produce fruit sooner.

For a container, use a well-drained mix. One suggested mix is 4 parts shredded aged pine bark to 1 part peat moss or coir. Choose a container with drainage holes.

Light. Give the tree full sun outdoors. Indoors, it needs a bright south-facing window and at least 6 hours of direct light daily.

Water. Keep the soil moist but never soggy, and let it dry slightly between waterings. Potted trees need more frequent watering than trees in the ground.

Soil and feeding. Citrus do well in soil with a pH of 5.5 to 6.5. Citrus are heavy feeders and need more nitrogen than phosphorus or potassium. Yellowing leaves may mean the tree needs more fertilizer.

Cold. Temperatures below 25 °F (about −4 °C) can cause significant damage, so move container trees to a protected spot before cold weather.

Pests on citrus can include brown soft scale and two-spotted spider mite, as well as spider mites, whiteflies, and scale. Root rot can occur when the potting mix is poorly drained. The plant is generally disease-free according to one profile. In South Carolina, citrus cannot be sold or shipped out of certain counties because of the Citrus Greening Quarantine.

Oranges take about a year to ripen. Citrus fruit ripens only on the tree, and it can stay on the tree in good condition after it is mature. Most citrus is self-pollinating. Indoors, you may need to hand-pollinate flowers to get fruit. Potted trees often drop some fruit, which is normal.