Question
Weeping Cherry tree has a jelly-looking sap at base of trunk. It is only 1 1/2 years old. Is this a diseases? Will it kill my tree?  What can I do? What caused this? Some of the leaves are turning orange. Thanks for your help.

Answer
This sounds like Gummosis. Weeping cherry is a grafted, ornamental tree, often used near water features in the landscape for its delicate, trailing habit. This little tree is tough and will attract few pests and diseases when given an open area to grow and substantial shelter from wind and harsh weather. Gummosis is a nasty condition that is more common to larger cherry trees like black cherry or sour cherry, than it is to the weeping cherry. Still, if you see evidence of this blight, often caused by phytophthora fungus, take quick action.

Look for the signs of gummosis: an orange or dark-red, gummy substance, much like sap. It may be present on the trunk of a weeping cherry if it's been injured by a grass whip or mower, or it can collect in the crotches of branches injured by wind or scalded by too much sun.


Prune off affected branches with pruning shears. Discard immediately in yard waste bags. If that's not an option, bury the affected limbs under at least 1 foot of soil.

Generally the gum will be coming from an injured place on the weeping cherry tree, or a canker. You may find cankers that are not producing gum; however, they will in the future. The cankers will look like a black spot or a bruised spot on the trees branch or trunk.

Scrape away any gum using a sharp knife. Use your knife and cut out the canker or damaged spot in the trees trunk or branch. Cut down into the branch or trunk, until you reach green or white healthy wood. Keep cutting until the entire canker or damaged spot it removed.

Treat gummosis on the trunk of a weeping cherry by cutting away the diseased bark with a sharp knife. Cut away a small amount of healthy bark to create a buffer zone between intact bark and diseased areas. Dispose of the cut bark immediately.

Apply a light spray of fungicide containing copper as soon as you have finished cutting, to prevent gummosis from spreading or affecting nearby trees.

Wash the blades of the pruning shears and knife with hot, soapy water, to prevent gummosis from spreading to other plants.

Allow the cut areas to dry out. Check to be sure that mulch is not contacting the base of the tree. The moisture retention of mulch can create bark rot--the perfect environment for gummosis to redevelop