• Tree diseases can occur in the roots, trunk or bark of a tree.birch tree detail image by Stephen Orsillo from Fotolia.com
  
  Caring for plants and trees requires more than just providing adequate sunlight, water and soil. Plants and trees are subject to a number of diseases and infections that can not only reduce the aesthetic appeal of plants and trees, but untreated diseases can permanently damage or kill plant and tree life. Many tree diseases are invasive and can be resistant to treatment. Preventative methods are the most effective methods of deal with flower and tree diseases.
  
  

Armilliaria Root Rot

• Root diseases attack and spread through the elaborate root structures of trees.the root image by Marek Kosmal from Fotolia.com
  
  There are several varieties of root diseases that can affect trees, but one of the most common is called Armilliaria root rot. Oak and fir trees are the most commonly affected trees, but most tree varieties are susceptible to root rot. The invasive fungus that caused root rot is transferred to trees through carrier parasites. The fungi feed off the nutrients of the tree, causing trunks, leaves and branches to die due to lack of sufficient nutrition. Root diseases are difficult to detect because they occur beneath the surface of the soil. By the time the effects are evident, most trees are too ill to be saved and will eventually die from the fungal infection.
  
  

Beech Bark Disease

• Healthy beech bark is free of holes or cankers.beech bark texture with algae, bw image by Scott Slattery from Fotolia.com
  
  Beech bark disease is caused by an insect that damages the bark of beech trees. The insect's incision in the bark leaves the tree susceptible to a fungal infection that causes large holes, called cankers, to consume the outside of the tree. The cankers spread over time until the tree is so rotted that it dies or becomes too weak to hold its trunk upright. Management of beech bark disease is mostly focused on controlling or destroying the insect that begins the process of the disease, though widespread efforts to control the insect have proved too costly to be viable.
  
  

Gray Mold

• Gray mold is one of the most common afflictions of flowering plants. Gray mold occurs when high levels of precipitation are coupled with below normal temperatures. Water-logged leaves become breeding grounds for the mold, which targets older flowers or foliage. The mold overtakes the plant parts in a furry coating of gray mold. The mold can be managed with a bacterial spray that feeds off of and kills the mold spores. Preventing gray mold requires avoiding overwatering and keeping plants in well-circulated areas.
  
  

Powdery Mildew

• The spores that create powdery mildew survive best in high humidity climates, so tropical plants and greenhouse plants are most susceptible to powdery mildew. Mold spores cling to leaves and other plant foliage, coating them in a white film that dehydrates the plant. Though most plants will not die from powdery mildew, the infection can weaken plant structures and cause the plants to droop. Powdery mildew can be prevented by treating the leaves of the plant with horticultural oil prior to infection and throughout the growth season. A spray made with baking soda and water can also be applied to plants as a home remedy.