Q.Weeping Hole in Magnolia Tree Trunk
We have a magnolia tree that has started to weep from the intersection of two trunks. It’s a dark coffee colored substance. No bugs appear to be present but it looks unhealthy and concerned this will lead to a weak trunk or the beginning of the end of our beautiful magnolia. What do we do to address this?
Cankers on trees should be pruned out to prevent the spread.
I'm not sure of the location of this canker on your tree.
There are several types of cankers and identification may be best done by a certified Arborist.
Here are some links with more information.
http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/cankerdiseases.html