A Semi-Dwarf Orange Tree Will Not Grow

Variety

• The semi-dwarf tree may have reached maturity if it is between 9 and 12 feet tall. If that's the case, it won't grow any taller. Full-sized orange tree scions -- the branching part of the trunk -- are grafted onto a dwarf trunk or rootstock. It could be your semi-dwarf tree is just finished growing.

Sun

• Citrus trees, and semi-dwarf orange trees are no exception, need full sun. If the tree is in a location where it receives less than six hours of sunlight per day, its growth will slow down considerably. If the orange tree is being shaded by taller trees, prune back the taller trees to expose the orange tree. As the seasons change, make sure that your tree's location is still receiving full sun. A location in full sun in midsummer may be shaded most of the day at other times of the year.

Water

• Lack of water prohibits growth. The tree may be receiving enough to keep on living but not enough to thrive. Too much water drowns the roots, which stunts a tree. Orange trees should be watered deeply once a week during hot summer months. Water with a hose placed in the basin around the tree so that the basin is full for at least an hour and the soil is wet to a depth of 3 feet. Cut the watering to every two weeks in the shoulder seasons.

Root Bound

• If your orange tree is growing in a container or in the Southwest desert, it may be root bound. In the desert, the soil has a hard layer of caliche -- calcium carbonate -- from 1 to 3 feet below the soil. The caliche prevents proper drainage and keeps the tree's roots from spreading. In a container, the pot holds the roots in check and the tree grows slowly, if at all. (It's similar to the technique of growing bonsai plants.)

Fertilizer and Nutrients

• Nutrient-poor soil affects the growth rate of plants. A lack of iron in the soil, or soil that's consistently damp, which prevents the plant's roots from absorbing the iron, results in chlorosis. The leaves turn yellow while the veins remain green. New growth is more affected than old growth. Eventually the tree stops growing. Add iron chelate to address this problem. Lack of nitrogen causes an overall yellowing of the leaves. New growth becomes smaller and smaller. Add fertilizer high in nitrogen. Test your soil with a kit and add soil amendments as necessary. If you don't want to test, call your agricultural university extension and ask what you should add.

Disease and Pests

• Leaf miners tunnel into the leaves of a semi-dwarf orange tree. Eventually the leaves curl and fall off. Aster yellows spread by leaf hoppers cause the oranges to be fibrous rather than juicy. A number of pests and diseases affect semi-dwarf orange trees. Examine the plant. If you don't know what's causing the problem, describe the symptoms to your local plant nursery, or clip off a branch and bring it down to the nursery for treatment recommendations.