Spring is the perfect time to get up close and personal with our trees, whether we’re admiring their new blooms or checking their health.
Colleen, a Davey blog reader, was doing just that when she asked, “I have a non-fruit bearing plum tree that seems to have some kind of sap coming from the trunk. Only a few branches feel fresh and healthy. The others feel dead and dry. Is this OK?”
Symptoms like these might point to a pest or disease. If you’ve seen something similar on your fruit tree, see what’s happening and how you can help.
Fruit trees leak sap for two main reasons:
Borers have infested them.
They could be suffering from a disease called cytospora canker.
Most commonly peach, nectarine, plum or cherry trees ooze sap, but why?
Insect borers and a fungus called cytospora canker creep into trees’ injured roots or branches. When tree roots are scratched by lawn mowers or nicked by unsafe pruning cuts, the wounds create an opening for pests and diseases. Trees weakened by weather stress are also easy targets.
Both pests and disease cause distinct symptoms you’ll see in early spring on your fruit trees:
Brown, sunken spots called canker sores that ooze brownish-orange sap
Dead twigs or full branch death
Droopy, wilted leaves that turn yellow or brown
If you also see large holes in the bark, it’s likely borers.
If you suspect borers… Control using preventative insecticides before the start of next year’s growing season. Treatment won’t reverse damage, but can help fight future infestations.
If you think it’s cytospora canker… Unfortunately, there is no cure, and it will often kill trees. Keeping trees healthy is the best way to stop sap before it starts.
To do this:
Take special care not to injure trees with lawn mowers or pruning cuts. Try raising lawn mower blades, so they’ll be less damaging to exposed roots. Or better yet, mulch your trees!
Fertilize and water trees proactively. Don’t wait until a problem appears.
If the tree is already experiencing cytospora symptoms, reach out to a professional and see if you can improve the health of your tree. Often, trimming dead or infected branches can help. And proper plant health care is always beneficial.
Sap dripping because of a pest or disease is much, much different than the tasty tree syrup we get from maple or birch trees. Your best bet is not to eat sap from unfamiliar tree species or from trees that display symptoms of infection – like those mentioned above.