Blight Killing Branches on Flowering Cherry Trees

By Gene Sumi

Flowering cherry trees at their best - no disease.

Flowering cherry trees, especially the late-blooming Kwanzan variety, have been hit with widespread dieback of branches and stems on their flowering cherry trees.  The branch tips die back, leaving clusters of dead, brown leaves.  The cause is a fungal disease called Brown Rot Blossom Blight.  The blight attacks fruit trees such as fruiting and flowering apricots, cherries, nectarines, peaches and plums.

Fungus spores infect the tree blossoms in the spring, when the blooms begin to age. Many tiny black spores begin to cover the dying flowers.  The spores become active and start to kill the branch tip and work back towards the trunk.

Once the dieback begins, the disease cannot be controlled.  The only recourse is to prune off the dead portions of the branches and dispose of them in the trash.  However, you can help prevent the reinfection of your plants by cleaning up all ground litter from the tree – it may still be harboring the blight spores.  The tree should then be sprayed in early spring with a fungicide recommended for control of that fungus.  They should be applied when the flower buds swell and begin to show petal color.  The tree should be sprayed again after all the petals fall. The applications are done to kill any spores that may be present on the tree.

For the prevention of Brown Rot Blossom Blight, these are the recommended fungicides to be applied to fruit trees in early spring:

  • Infuse, by Bonide.  Active ingredient:  Propiconazole
  • 3-in-1 Insect, Disease & Mite Control by Bayer Advanced.  Active ingredient:  Tebuconazole.
  • Serenade, by Agra Quest.  Active ingredient:  QST 713 strain of Bacteria subtilis.
  • Sulfur Plant Fungicide by Bonide.

Sources:  Oregon State and Scott Aker, horticulturist at the U.S. National Arboretum.

5 Responses to Blight Killing Branches on Flowering Cherry Trees

  1. Saffron says:

    I have a quick question: Does this particular fungus look like little grains of white rice? A cherry blossom of mine died last summer from a fungus and this same fungus has now spread to 2 of my lilacs.

    Thank you in advance:)

  2. Gene Sumi says:

    From your description and photo of the answer to your question is no. The spores of this fungal blight should appear on the blooms a small black specks, almost like uniform-size round ground black pepper. The round white balls are more indicative of powdery mildew fruiting bodies, which commonly appear on the leaves of lilacs in mid-summer. Powdery mildew may be found on the flowering cherry, but it does not usually kill its host.

  3. Paperfldr says:

    My huge, gorgeous double-flower ornamental cherry has had this disease for years – despite being treated for it by a supposedly reputable tree care company. This year it has been especially bad & the tree looks terrible. Should I look for a different company to treat my tree? What else can be done? They sprayed it in mid February and again in mid May, but with what, I don’t know.

  4. Christine says:

    Our Kwanzan cherry trees did not bloom this year, they have very few leaves and some of those are dying and falling already. There are new shoots coming out from the trunk. We had a hard winter (in Michigan) and we attributed the lack of flowers to that but know I am not sure. We previously lost trees to the Emerald Ash bore, is there something else going through Michigan that is now killing cherry trees?

    • Rachel Baumgarten says:

      The problem could be a tree borer. For cherry trees, it could be one or more of several species of insect tree borers. The Peach Tree Borer, Lesser Peach Tree Borer, Plum Borer or Dogwood Borer are all possibilities on cherry trees. All of these borers damage the Cambium layer which lies just under the bark of the tree. In damaging this layer, they also damage the vessels that bring water up from the roots and sap down from the leaves. Extensive damage to this important part of the tree trunk and major branches can mean that nutrients, water, and food may be cut off from the leaves and roots. This means severe wilting of leaves immediately and you can see the death of the tree branches affected in a matter of days. Please check with the Michigan State University Extension for specifics as to what borer may be doing the damage and its recommendations on a control for it.

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