What Causes Oak Tree Leaves to Stop Developing?

Iron Chlorosis

• Iron chlorosis causes leaves on an oak tree to stop developing by depriving the tree of the iron it requires from the soil to maintain health. The problem stems not from too little iron in the soil, but rather from the oak tree's roots being unable to absorb it. A pH level of 7.0 or above indicates that the soil is highly alkaline. Ideally, for the roots of the oak to uptake iron, the soil should include some acidity, with a pH level below 7.0.

Effects and Solution

• Iron chlorosis is clearly identifiable when the leaves of the oak tree take on a yellow color while the veins maintain a prominent green. In severe cases, the leaves will die and fall prematurely from the tree; the death of individual branches, and potentially the entire oak, is possible. The direct application of iron chelates and iron sulfur, in addition to foliar sprays, help to provide the tree and leaves with the missing iron.

Oak Galls

• The foliage of an oak tree is susceptible to infestation from an insect whose presence and feeding patterns slow the development of the leaves. Oak galls are housing and feeding structures built on the leaves of an oak by wasps. Application of insecticide is rarely effective, as the insects are well-protected inside the hard shell of each gall. Fortunately, the damage these pests cause is primarily cosmetic.

Oak Wilt

• The fungus known as oak wilt is brought on by the pathogen Ceratocystis fagacearum. It is a lethal disease that not only stops oak leaves from developing, but nearly always results in the death of the entire tree. The disease first presents itself in the crown of the oak and begins to work its way downward, causing the growth of foliage to be stunted through a wilting, browning and drying of the leaves. The majority of oaks die within one year of infection. There is no cure for oak wilt; the tree must be removed and destroyed.