My black tulip magnolia has some damage to its trunk. How can I repair this? The bark is stripped to the bare trunk – about nine inches and there is a crack in the trunk. I do not want to lose this tree. I am still waiting for it to flower.
Thank you for contacting the Toronto Master Gardeners with your magnolia question.
Black Tulip Magnolia is best grown in moist, well-drained, preferably acidic to neutral soil in sun or partial shade. Although magnolias are quite pest and disease resistant, they can be susceptible to several bark diseases. They have thin bark and any injury or pruning damage can allow bacteria or fungus to enter the tree. Some of the possible bark diseases are Nectria Canker, Wetwood and Armillaria Root Rot. I have attached a link to a site that explains these three diseases and what you can do to help your tree. If the condition continues, you may wish to consult a certified arborist who may be able to help you save your tree.
https://www.gardenguides.com/117212-magnolia-tree-bark-diseases.html
Because of their thin bark, magnolias are also susceptible to bark damage from frost cracking and sunscald, particularly if the damage is on the south or southwest side of the tree. Click here for an article that explains this occurrence.