My Shrubs Are Turning Black / Brown

My Shrubs Are Turning Black/Brown : Learn What’s Causing The Problem And How To Fix It!

Black Shrubs

Sooty Mold On Eucalyptus Tree

My Shrubs Are Turning Black:

In 90% of cases of shrubs turning black, the cause is a fungus commonly known as Sooty Mold. Sooty Mold is a fungus that grows on the excretions of a plant-sucking insect.

In small amounts, Sooty mold is typically not harmful, but in large amounts, it can coat leaves of your shrubs to the point where they cannot absorb sunlight. This means that the process of photosynthesis is interrupted and they will not be able to produce the nutrients they need for survival.

To treat sooty mold you need to suppress the plant-sucking insect population. Once the insect population is in check the sooty mold will begin to disappear.

My Shrubs Are Turning Brown:

Unlike black shrubs, shrubs that are turning or have turned brown can be caused by a number of issues. The three main issues that would result in browning shrubs are drought stress, winter damage, and disease.

Drought Stress:

With drought stress, the leaves wilt, begin yellowing, and turn brown from the outside moving inward. You can combat drought stress by thoroughly watering trees and mulching around the base of the tree to retain moisture. To find out how much water your tree needs to thrive check out our watering article.

Brown Shrubs Winter Damage

Winter Damage On Evergreen Shrubs

Winter Damage:

Most of these negative effects of winter stem from the fact that trees and shrubs lose moisture through their pores which are located on their leaves/needles. During the winter months, the dry air and wind accelerate this effect leading to leaves increasing their water demand from the roots in order to survive. However, the root system usually has a hard time keeping up with the leaves’ demands. The result: leaves and needles turning brown and dying. This cycle is called winter burn.

Because our last frost was late this year and trees/shrubs had started pushing out new growth, winter burn is prevalent around the DC metro area.  


Brown spots and the browning of leaf veins while the rest of the leaf is still green are tell-tale signs of shrub disease. If your shrub is suffering from an overall browning and you have ruled out winter damage or drought stress, it may have a root disease. Common diseases in this area include anthracnose, leaf spot, Armillaria root rot, and Phytophthora root rot.  To correctly identify the type of disease your shrub is suffering from a Certified Arborist will need to inspect your shrub and its leaves.

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Samantha Huff

Samantha Huff is the marketing coordinator at RTEC Treecare. She enjoys learning about the technical aspects of trees and the insects and diseases that prey on them. She hopes that these articles can help homeowners gain control of their tree and shrub maintenance by being aware of the signs and symptoms of unhealthy trees.

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2 thoughts on “My Shrubs Are Turning Black / Brown”

  1. Munire Nilson says:

    Especially our Azelea bush branches are turning black and there are white spots on them, which are probably the insects that are mentioned in the article. Can you please recommend a form of treatment / or a chemical to treat this disease.
    Thank you,
    Munire Nilson

    1. Rtectree says:

      Ms. Nilson,

      Thank you for your comment!

      There are numerous plant-sucking insects that could be creating your sooty mold problem (black spots) and treatment is specific to the certain type of insect. To make sure the problem is taken care of correctly one of our Arborists would need to inspect your Azaleas. We’d be more than happy to send the Arborist who has serviced your property in the past out to take a look. I will email you directly so we can discuss further.

      Thank you,
      RTEC Treecare

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