Soil Acidity

• The pH of your soil affects how the roots of your white oak interact with the nutrients in the soil. Changing the acidity of the soil can limit your tree's ability to absorb nutrients. Certain types of fertilizer, naturally occurring substances and heavy rainfall can affect your soil's pH rating, with detrimental affects for your trees. Performing a soil test will provide information about the current pH levels of your soil. Soil testing services are often available from county or university cooperative extension services. Having the soil tested before you attempt to change your soil pH will provide valuable information about the current pH and buffering capacity of the soil. Buffering capacity indicates your soil's resistance to changes in pH and the amount of acidic or basic material required to change it.
  
  

Impact

• White oak trees planted in a soil with a high pH rating will not absorb nutrients from the soil properly. Under these conditions white oak trees are subject to a condition known as chlorosis. Chlorosis is one of the first signs of a nutrient deficiency resulting from a high soil pH level. In white oak trees, chlorosis is often the result of an iron deficiency although pH levels above 8.0 will also limit the ability of your tree to absorb other minerals. Highly acidic soils with a pH below 5.0 are also a hazard for white oaks because they increase the availability of iron, manganese and aluminum in the soil to potentially hazardous levels.
  
  

Symptoms

• The most common symptom of pH problems in white oak is chlorosis of the leaves. Trees suffering from chlorois exhibit yellowed leaves that can appear whitish in extreme cases. The key defining attribute of chlorosis is that the veins of the leaves remain green while the rest of the leaf is yellow. Mild cases of chlorosis will affect only certain branches of the tree or only appear sporadically. White oaks suffering from chlorosis are often more susceptible to fungal infections of the leaves. More serious cases of chlorosis will affect the entire tree and weaken or kill it unless the problem is treated.
  
  

Soil Ammendment

• Soil amendment is the process of changing to properties of the soil using a mechanical or chemical process. In areas where you need to decrease your soil pH levels, there are several natural and chemical options. Powdered sulfur is a common method for gradually lowering soil pH. Applications of aluminum sulfate will produce faster results but is toxic to plant roots if applied incorrectly. In areas with an overly acidic soil, applications of powdered lime are an effective method for increasing the pH level of the soil.