Unhealthy Apple Tree

(Question)

We have a med / large Apple tree in our back yard. It never produce healthy Apple .
How to treat it for healthy Apple ?

(Answer)

Thank you for your question regarding your apple tree. It is definitely frustrating if you have an apple tree that doesn’t produce a healthy crop of apples. You mention that your tree is medium to large in size so it appears that it is not a newly planted tree. Below are several reasons for issues with apples. It is difficult to narrow down your problem without more specific information such as age and variety of the tree, the location on your property (sunny or shady area, in the lawn or a garden bed). A photo of an apple with the problem would be helpful.

The tree isn’t producing any apples.

  1. Apple blossoms may be killed by an early frost. The average last spring frost in Toronto is April 30. See frost dates here Ontario Frost Dates
  2. Apple trees are not self-fruiting. They require a second apple or crabapple to cross-pollinate. Both trees should bloom at about the same time of year to ensure good cross-pollination. Read about cross-pollination. (An interesting side note is that there are trees available that have 3 or more varieties of apples grafted onto one tree. This allows for cross-pollination in one tree.)
  3. Once an apple tree produces fruit, it will benefit from a light application of a complete fertilizer (such as a 10-10-10 mix) in early spring. Follow directions on the fertilizer bag. If the tree is grown in a lawn, applications of nitrogen-only fertilizer for the lawn may produce an abundance of leaves instead of blooms.
  4. Once an apple tree produces fruit, it will benefit from light pruning in early spring (before the new buds swell) to remove weak, damaged, or crowded branches, as well as suckers.

The tree produces apples but the apples are diseased.

  1. Sanitation is very important to help manage diseases and insect pests. Make sure the tree has an open canopy to allow light and good air movement into the middle. Clean up infected or diseased leaves, branches and fruit. Do not add to your home compost pile.
  2. There are several diseases that affect apple trees such as apple scab, rusts, cankers and fire blight. Here is a list of diseases that may help you to identify your problem.
  3. There are few chemical options for the home gardener to control diseases and insects in Ontario. The Ontario Pesticide Act does not allow the use of restricted pesticides by homeowners for non-essential or cosmetic uses. You may be able to purchase copper and sulphur containing products to control fungal and bacterial diseases.

The tree produces apples but the apples are damaged by insects.

  1. There are many insects that affect apple trees but several that attack the fruit directly are codling moth, oriental fruit moth, plum curculio and European apple sawfly. If you notice webbing in the spring, it could be the Eastern tent caterpillar — it will eat the leaves of the tree and the tiny fruitlets will not develop. Here is a list of pests that may help you to identify your problem.
  2. As mentioned above, there are few chemical options for home gardeners. Insecticidal soap is an option for soft-bodied insects but would be difficult to use in this case as it must come into contact with the insect to be effective and applications may need to be repeated as per directions on the label. Dormant oil may be applied before the buds break dormancy in early spring to manage outbreaks of scale, aphids or mites. However, dormant oil sprays do not control common home garden pests like the apple maggot.