Dwarf citrus trees provide year-round interest to the garden. They are evergreen, with shiny green foliage and sweetly fragrant flowers in spring. They bear full-sized fruit that ripens between late autumn and early spring. When grown in the ground, they can reach heights between 10 and 12 feet but can easily be pruned to any size. Container-grown citrus rarely grow taller than 8 feet.
Choose a sunny location with well-drained soil that is protected from strong winds. Some species can do well in partial shade but will not produce a good crop of fruit. The site should be large enough to accommodate a full-size tree, and 6 to 8 feet from any buildings.
Plant the container-grown tree in a prepared planting hole, making sure to plant it at the same height as it was in the container. This is important because most dwarf citrus are produced by grafting. The planting hole should be twice as wide as the container. Add plenty of organic material (manure, compost, leaf mold) to the soil that has been removed, and use it to back fill around the plant. Do not add fertilizer at this time. Water gently to settle the soil around the roots of the plant. Some trees may require staking their first year.
Fertilize your trees three times a year. In Florida, trees are fertilized between mid November and the end of April. In other areas, such as Arizona and California, the applications should be later, between February and May. Citrus trees are heavy feeders and need additional nitrogen. A balanced fertilizer with a slightly higher percentage of nitrogen is recommended. In some areas, special citrus fertilizer can be purchased at garden centers.
Water your citrus weekly during dry spells. Citrus will tolerate dry conditions, but fruit production will be poor. At the same time, citrus will not tolerate wet feet. The soil must be well drained.
Prune weak, dead or diseased branches as well as any branches that emerge below the bud union. These are called suckers and emerge from the root stock. You can locate the bud union a few inches above the soil line. It is recognizable by the diagonal scar or bulbous shape. Thin out the branches to increase air circulation. Citrus adapt well to pruning and can be cut back to maintain a desired size.
Identify any problem before treatment. Most insect infestations can be knocked out with a forceful stream of water. Citrus trees can withstand some insect damage with few consequences. For heavier infestations, a reputable garden center can recommend a solution. Common insect problems include spider mites, white fly, California red scale and aphids. Common fungus diseases include anthracnose, leaf spot, scab and greasy spot.
Protect your citrus plants when freezing temperatures are expected. Most citrus can withstand temperatures as low as 28 degrees. Water plants thoroughly. This will allow the soil to release more heat around the plants. Cover smaller trees with blankets. Citrus trees grown in containers will freeze sooner that those planted in the ground. If possible move them to an unheated indoor location.