All citrus trees are easy to grow in the home landscape. If you live in a warmer climate zone, such as zone 9 or higher, you can grow most citrus outdoors. But in cooler climates, you must protect your citrus tree from frost. A good way of doing this is to grow it in a large container, which you can bring indoors when winter approaches. Whether your citrus tree lives outdoors or in your home or greenhouse, insects can attack it. Most insects are easy to control, but be sure to “nip them in the bud” when you first discover them.
Watch for ants. Although ants do not harm your citrus tree, they bring insects that do. Both aphids and scale insects secrete a sweet substance called honeydew that the ants eat. When you first notice ants on your plant, spray it with a sharp stream of water to knock them off and then smear a product called Tanglefoot around the trunk to prevent them from returning. Follow label instructions on the package. Ant stakes that you stick into the soil can also help.
Spray with insecticidal soap if aphids, spider mites or young scale insects appear, especially on the undersides of the leaves. Soap sprays are available at your garden center or you can make your own with 1 tbsp. of mild dish washing soap mixed with one quart of water.
Control adult scale insects by mixing 1 tbsp. of cooking oil, such as canola, with your insecticidal soap. Because older scale insects develop a tough “armor,” they can be harder to eliminate than the younger, soft-bodied insects. The oil spray prevents them from breathing.
Protect your citrus tree from snails and slugs. Prevention is the best cure, so scatter iron phosphate granules or diatomaceous earth around the base of your tree and refresh your application of these products periodically, according to label instructions.
Hang sticky traps to control white flies if they should appear around your citrus tree. These traps are typically yellow--you can purchase them at any garden department.