Orange oil, technically called d-limonene, is the result of crushing and extracting the contents of the orange fruit's rind. The effects of the oil's enzymes and natural acids may have a beneficial influence on garden plants. For example, orange oil can act as a natural insecticide to ward off pests and help plants devote all of their energy toward proper growth and development. In some cases, the effects may be on par with that of synthetic plant treatments, making orange oil an effective and all-natural solution to common garden problems.
Sterilize the soil. This can help kill fungus and soil-borne insect pests that may be hampering plant root growth, and may be especially beneficial for potted plants where fungus can be a critical problem. Mix 2 oz. orange oil with a gallon of fresh water. Pour onto the soil.
Kill bug pests, such as aphids, beetles and ants. Orange oil's acids penetrate insects' exoskeletons and quickly kills them. Pour a quart of water and 1/10 oz. orange oil into a plastic spray bottle.
Close the bottle and shake it to mix the contents thoroughly. Mist onto problem areas on your plants to kill the bugs.
Clean your plants to destroy any mold and fungus growth. Such growth can be significantly troublesome on house plants. Mix 1/4 oz. orange oil with 2 qts. water. Slosh the solution over your plant to thoroughly soak all of its foliage.