We have a maple tree in our front yard, facing south. We have a maple tree (type?) that lately has been leaking black stuff on our sidewalk. Does it need to be cut down?

A maple tree leaking black sap could indicate several issues, including fungal cankers, bacterial wetwood, or insect infestations. Black sap is often associated with diseases or conditions that damage the tree’s tissues, such as slime flux (bacterial wetwood) or bleeding canker, which are visible as dark sap or slime oozing from the bark.
Here’s a more detailed breakdown of possible causes and what to do:
Possible Causes:
· Bacterial Wetwood (Slime Flux):
This condition is caused by bacteria entering the tree through wounds, producing a slimy, blackish ooze and potentially fermenting into alcohol.
· Fungal Cankers:
Cankers are lesions on the bark caused by fungi or bacteria, and can ooze dark sap.
· Insect Infestations:
Certain insects, like aphids, can feed on the tree’s sap, causing a sticky, sugary substance that can attract ants and other insects.
· Bleeding Canker:
This is a disease that causes cankers on the tree’s trunk, often accompanied by dark brown or black sap.
What to do:
· Identify the Cause:
Observe the tree closely for signs like dark spots, cankers, or insect activity.
· Remove Cankers:
If the tree has cankers, carefully remove them and treat the wound with a 10% bleach and water solution and then use an ‘end cut’ product to cover the wound.
· Address Insect Infestations:
If insects are the problem, try organic solutions like soap and water or dormant oil. If you want to use dormant oil the window closing quickly and you would need to do it now.
· Manage Stress Factors:
Ensure the tree has adequate water and sunlight, and consider fertilizing if needed. Trees under stress are more vulnerable to disease and insect infestations.