Orange trees are thought to be native to southern China. These trees are beautiful when grown indoors, with their shiny green leaves and bright-coloured fruit that ripens around midwinter. White fragrant flowers bloom in May and add a sweet scent to your home. But caring for an indoor orange tree requires a little know-how to keep it in top shape.
Light, Watering & Fertilizer
Orange trees need plenty of bright light. Sit an indoor tree near a large window, preferably one that faces south. If necessary to provide enough light for the tree to thrive, use full-spectrum fluorescent lights; hang them approximately 4 to 5 inches above the tree. Watch for scorched leaves, which signal too much bright sunlight. If this happens, move the tree away from the window and use grow lights, or place in front of a window that doesn't get hot afternoon sun.
Water every day or two just to keep the soil moist. Check the soil before watering to see if it is dry. It should be dry down to about 1 to 2 inches before watering. If the tree is dropping leaves it can be a result of insufficient watering. Yellow leaves may signal too much water. It may not be necessary to water as much during the winter months. A layer of mulch can be added to the pot to help hold in moisture.
Fertilise with a citrus plant fertiliser every three months during the growing season. Do not fertilise in the winter months.
Pruning & Pests
Orange trees respond well to pruning. Prune your tree in early February before new growth begins. Trim off all dead branches and thin to three of the strongest branches. Do not cut off too many leafy branches; the tree stores its food in the leaves, and cutting off too many will reduce the fruit production.
Spider mites and mealy bugs are the most common pests found on orange trees. Check your tree often for signs of these pests, which include webbing and small holes in the leaves. Use either a commercial pest spray or make a 1:1 mixture of rubbing alcohol and water; spray the leaves with the 1:1 alcohol mixture, wipe down with a clean cloth and respray. Recheck in a few days for the pests; if there are still signs of them, use the alcohol spray again.
Potted orange trees are root bound, meaning that they are grown in shallow containers to help maintain the tree's small size. Replant about every three to four years to keep these trees growing their best. Do not plant in a container that is any more than twice the width or depth of the root ball. Replant either early spring or in the summer; it is best to replant before or during the growing months, not during the dormant season in the winter.