How to Cure Brown Leaf Disease in Shrubs

Remove Stress Factors

• 1

  Check for appropriate drainage around the shrub. When the leaf turns brown on the edges, stress is normally the culprit. Roots sitting in soggy soil are stressed. Stressed shrubs are more susceptible to disease. Adding sand or organic matter increases drainage. Reduce watering if necessary.

• 2

  Remove other stress factors, such as underwatering. Most shrubs need 1 to 2 inches of water per week from naturally occurring rain or manual watering. Watering deeply when the shrub is young encourages deep root development. Deep roots need less watering and eliminate stress.

• 3

  Water the shrub at the base; avoiding wetting the foliage. Overhead irrigation encourages brown spot disease such as Septoria or Gloeosporium leaf spot.

• 4

  Check for insects that are notorious disease carriers. If insects are present, remove them with a blast of water from the hose, a thorough spraying of insecticidal soap or a fungicidal drench.

• 5

  Prune damaged or diseased limbs. Clean the pruners between each cut with an alcohol or bleach solution. Air circulation among branches discourages brown leaf disease by decreasing humidity.

Encourage a Healthy Shrub

• 6

  Fertilize the shrub if not done so recently. If new leaves appear near damaged ones, fertilization is likely not needed.

• 7

  Make sure soil around the plant is not compacted. If water cannot get to the roots, leaves may turn brown and die. For compaction problems, incorporate organic matter into the soil.

• 8

  Remove several damaged leaves and take them to your local Cooperative Extension office for diagnosis. These horticulture professionals stay current on disease issues and can diagnose if your brown leaf disease is fungal, bacterial or viral. Agents and master gardener volunteers can offer solutions for whatever disease is present.