Thats what a neighbour asked me recently. See the picture above? A lot of amber-colored, jelly-like goop was coming out of his cherry tree’s trunk and branches.
That sticky goop is called gummosis and its a sign that a tree is under stress. But what causes gummosis? And how can you prevent and treat it? Well explore that in this article.
Nothing strikes dread into the heart of a cherry tree owner like the sight of sap bleeding from the bark. This troubling condition, known as gummosis, can indicate serious issues that threaten the tree’s health. Understanding what causes oozing sap on cherry trees is key to resolving the problem.
What is Gummosis?
Gummosis refers to sap exuding from wounds or cankers on woody fruit trees like cherries, peaches, plums, apricots, and citrus. The sap appears as globs, drips, or streaks on the bark. It often smells sour and feels gummy or sticky to the touch.
While some leakage of sap naturally occurs in trees, excessive oozing indicates a more serious underlying issue It’s the tree’s desperate attempt to compartmentalize damage or disease. But too much sap loss saps the cherry tree’s vigor over time.
Common Causes of Gummosis
There are several potential explanations when sap starts oozing from cherry bark
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Canker diseases – Fungal infections create sunken dead areas (cankers) that ooze sap. Common culprits are cytospora, valsa, and perennial canker.
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Borers – Larvae of insects like peachtree borers tunnel under the bark, causing sap flow. Sawdust-like frass near sap is a telltale sign.
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Environmental stress – Extreme weather, poor soil, insufficient water, and nutrient deficiencies stress the tree, leading to gummosis.
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Mechanical injury – Damage from lawn mowers, string trimmers, frost cracks, and other physical wounds can trigger sap oozing as the tree tries healing.
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Improper pruning – Cutting branches improperly allows disease entry, leading to canker development and gummosis.
Catching gummosis early allows you to identify and address the cause before major harm occurs.
Dangers of Gummosis
While a minor sap leak here and there is no big deal, extensive gummosis weakens and threatens cherry trees in several ways:
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Structural instability – Cankers create weak areas prone to breaking, especially with heavy fruit loads.
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Nutrient loss – Oozing sap saps energy reserves needed for growth and production.
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Pest vulnerability – Sap and cankers attract insects and diseases.
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Reduced yields – TREE GOES INTO SURVIVAL MODE, PRODUCING LESS FRUIT
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Lower cold hardiness – Gummosis leaves trees more prone to winter damage.
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Spread of decay – Cankers expand, allowing rot to take hold.
Swift treatment of gummosis is required to avoid decline and death of affected cherry trees.
Solutions for Oozing Cherry Trees
If your cherry tree is bleeding sap, here are some corrective steps to take:
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Identify the cause – Look for cankers, insects, wounds, and other symptoms pointing to a source. Have a professional inspect if unsure.
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Improve growing conditions – Rule out environmental stressors like drought, extreme heat, or poor drainage.
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Apply fungicides – Protect healthy bark and spray cankers to prevent fungal spread.
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Use insecticides – Target borers and other pests attacking the wood.
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Prune out cankers – Cut 6 inches below and beyond visibly diseased bark. Sterilize tools between cuts.
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Protect wounds – Paint pruned areas and wrap injuries to prevent reinfection.
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Provide extra care – Mulch, fertilize, water, and prune properly to support recovery.
With diligent treatment guided by the sap’s clues, gummosis can be overcome and cherry trees returned to flush, abundant fruiting.
Identifying Cytospora Canker
The most notorious cause of gummosis on cherry trees is cytospora canker, a fungal disease. Some clues pointing to cytospora:
- Cankers form on scaffolds and main branches
- Dead bark is reddish-brown and sunken
- Oozing occurs early spring through fall
- Leaves wilt suddenly on affected branches
- Entire branches rapidly die back
Cytospora enters through bark injuries and pruned sites. It causes extensive gummosis, dieback, and decline when left unchecked. Vigilant pruning of diseased wood is required to save the tree.
Preventing Gummosis
While gummosis treatment is aimed at the cause, prevention focuses on minimizing risks:
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Choose disease-resistant varieties like ‘Montmorency’ or ‘Meteor’
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Prune judiciously in dry weather to avoid wounds
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Disinfect pruning tools between trees
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Allow proper spacing for air flow
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Maintain vigor with regular fertilization
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Irrigate during droughts to reduce stress
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Protect trunks from lawn damage
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Apply preventative fungicides and insecticides
With good cultural care and hygiene, you can stop gummosis before it ever starts!
When to Worry About Oozing Sap
Occasional sap leakage from small wounds isn’t necessarily alarming. But extensive gummosis, especially from cankers, requires rapid response.
See a professional if oozing can’t be explained, spreads aggressively, or if the cherry tree shows sudden decline. In severe cases, removal may be required to prevent infection of other trees.
While gummosis in cherry trees is always serious, solutions exist in most cases with prompt action. Identify the source and treat appropriately to preserve the tree and bountiful harvests to come.
Bacterial canker as a common cause of gummosis in cherry trees
There are many things that can hurt your cherry tree, but a bacterial disease called Pseudomonas syringae, which is also called bacterial canker, makes things worse. This pathogen affects other stone fruit trees as well like plums, apricots and peaches.
Brown spots or holes on the leaves and the death of new shoots and young branches are also signs of bacterial canker.
There are many possible causes of gummosis in cherry trees
So, what are the causes of gummosis in cherry trees? There are a number of possibilities:
- A string trimmer or mechanical injury can cause gummosis.
- Gummosis can happen when a branch is broken, torn, or pruned wrong.
- A sunburn on the tree’s trunk can turn into gummosis.
- Or an insect, like a peach tree borer, can set it off.
- Most of the time, though, gummosis is caused by an infection with bacteria or fungi. What makes those infections get into the tree? Well, they take advantage of any chance they get! These pathogens get in when the tree gets hurt in one of the ways listed above!
Lets see how tree wounds develop.
- The tree was hurt by a string trimmer, a bad pruning cut, or an insect that got through the bark.
- A canker, or sunken spot, appears on a tree’s branch, bark, or trunk. That canker might be a darker color than the trunk, and it might get hard and curl up around the edge.
- The branch might get bigger, and the tree will start letting out sticky sap.
In the early stages, it may be easy to miss a fungal or bacterial canker, but these cankers are easy to spot when the tree’s sap starts to leak. Think of the gummosis as your fruit trees call for help. As the grower you need to resolve this problem. before it is too late!.
Cherry Gummosis – This Week in the Garden
FAQ
How do you treat gummosis on cherry trees?
Is the sap from a cherry tree poisonous?
What to do if a tree is leaking sap?
Why is my cherry tree sap oozing?
If the sap oozing from cherry trees is free of sawdust and more than a foot above the ground, you’re probably looking at canker disease. There are a few types of canker disease that cause sap oozing from cherry trees, and all of them result in sunken, dead material (or cankers) around the ooze.
Why is my fruit tree oozing sap?
If you notice one of these trees oozing sap through fissures in the tree and the sap is killing grass below it, it’s likely bacterial wetwood. 2. Cytospora Canker (Gummosis) Gummosis most commonly affects stone fruit trees (trees that produce fruit with pits, such as peaches, cherries, plums, etc.).
What causes gummy sap leaking out of a fruit tree?
However, gummosis can also be caused by any wound to a stone fruit tree, including winter damage, disease damage, or damage from a gardening tool. If you see gummy sap leaking out of your peach, plum, cherry, or apricot tree, it is probably gummosis.
Why is gummy sap leaking out of my peach tree?
If you see gummy sap leaking out of your peach, plum, cherry, or apricot tree, it is probably gummosis. Once you understand what causes gummosis disease – wounds to the bark of a tree – you can begin to think of gummosis prevention. Any action you can take to prevent bark wounds will also assist with gummosis prevention.
What does gummosis mean on a cherry tree?
It’s called gummosis, a sign that your cherry tree is under some sort of stress. That’s right, trees can get stressed! Gummosis is not a disease but can be associated with disease or insect damage to the tree. Gummosis is most common on stone fruit trees such as plums, peaches, nectarines, and cherries.
Why is my Cherry Tree oozing?
Sap oozing from cherry trees can be brought on by a few different things. It’s so common in fruit trees, in fact, that it has its own name: gummosis. One very obvious cause is injury. Have you used the weed whacker a little too close to the trunk recently?