Xtremehorticulture

Plum Sap Not Always Disease or Insects

Q. My plum tree has sap
coming from it in bubbles. Does it have some sort of disease?


A. Sap coming from a tree is a response by the tree to
some sort of damage. Damage that causes sap to ooze in bubbles from the trunk
or limbs can be caused by the environment, disease or insects.
Plums
are normally very sappy. When plums are pruned during the growing season they
respond to fresh wounds by releasing a large amount of sap. Trees that produce
sap in response to damage or an attack is their method of protecting
themselves.

Sap losing from cut limb on plum

When
insects that burrow into the tree and attack it, such as borers, the release of
sap can engulf these burrowing insects and suffocate them. If the burrowing
insect is still active, chewing and feeding away when sap is released, these
bubbles of sap will be dark in color but cloudy. The sap is cloudy because it
is full of sawdust or wood chips from the feeding by these chewing insects.
If
the tree successfully engulfs and kills this destructive critter, the sap continues
to be dark but free of sawdust or wood chips and therefore clear. Sap also
helps flush disease organisms from wounds.
The
presence of sap from plums and apricots does not always mean there are disease
or insect problems. Sometimes environmental damage to the tree can cause
sappiness. Environmental damage can occur from intense sunlight, heat and water
stress.
Take
a sharp knife and remove the bubbles of sap all the way to the surface layer of
the tree. Remove the surface layer of the tree so that you can see what’s going
on just under the bark. Look at the exposed area under the bark and inspect it for
insect damage. You may find the insect itself.
Regardless,
it is a good idea to remove the sap bubble and inspect the exposed limb or
trunk just under the bubble. If an insect or its damage is present, clean out
the damaged area so that everything looks healthy and the tree can heal on its
own.

There
is no reason to apply anything to this wound afterwards if the knife was sanitized first. Use alcohol
to sanitize the knife, heat from a lighter or household sanitizer such as Pine-Sol.
Be careful with bleach, (even though it is a good sanitizer) because it rusts
tools and destroys clothing.

1 thought on “Plum Sap Not Always Disease or Insects”

  1. Looks like you have a sapsucker bird problem. The sapsucker makes (bores) holes in the tree and then comes back to eat the sap and the insects that stick to the sap. Usually it attacks one tree predominately, a younger tree with sweet sap. If you do not catch it in time, the tree will bleed out and die off as it is riddled full of holes. Solution: Wrap aluminum foil around the trunk of the tree and go get some bird netting, and put that around the tree. Its a little unsightly but it works. Do a search for "sapsucker" on the internet. They usually attack low at the base of the trunk and not so much up high on the limbs. Good luck.

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