Our Norway Maple had its tree bark splitting this spring. Initially it appeared as a 3 foot split (length), with an exposure of the undertree by a width of 2"-3".

What is causing this and what can be done to preven tree loss?

Thanks.

Hey, Diane! What you've described is probably a frost crack. It is very common on Norway and red maples, due to their thin bark. It usually occurs on the south or southwest side of the tree and is a response to extreme fluctuation in temps between night and day. A sudden drop in the temperature causes the outer layer of wood to contract more rapidly than the inner layer, which results in a long vertical crack at weak points in the trunk. But trees have their own way of healing themselves, without help from us...The wood around the wound begins to produce special compounds in its cells that put up a barrier to stop decay. This is called compartmentalization. Any attempt to "help" on our part can breach that barrier and further problems can result. My advice is to wrap the trunk during the winter months for the next few years, until the tree is older, to help moderate the temperature fluctuations, and visually monitor the overall tree health!

My Crimson King Maple is quite large and old and has always had some bark loosening on the south side of the tree. However, it is becoming more pronounced and causing deeper cracks in the tree trunk. Could this be fatal to the tree, and should there be some intervention? It is gorgeous tree and would be a huge loss to the property.

Thank you for your help.

Kay - It sounds like you are probably dealing with older frost cracks that have healed over, but could still be hosting fungi that can rot the heartwood. When you look up from that side, is the canopy thinner than the rest of the tree? You might want the opinion of a professional arborist, particularly if it is in proximity to your home.

Just a follow up question..I did call a very reputable tree guy and he said it was frost crack and healing just as you mentioned..but it is continuing up the tree and each branch on that south side is now dying = two more this year so far. It's a kind of "hidden" side..so I'm fine with that..but will it eventually stop moving up? (about 7foot high now on a 28' tall tree)

Cecilie - According to Dave Robson, one of the Extension Specialists "The cracked zone in the heartwood never completely heals, even though the surface may be sealed by callous formation; and the same cracks tend to open again each winter. The repeated splitting and healing eventually results in a mass of callous over the crack. Some trees eventually grow large enough in diameter or grow enough bark that cracking ceases. Until that happens, there is little that can be done." So, yes, hopefully the tree will outgrow it.

Really! Cool..well we will hope for the best. Should we wrap it this winter..and with what? (or a website that says how..is fine too) thank you so much for the answer! gives me hope.

Cecilie - From what I've read, wrapping does NOT help existing cracks. Good luck! I'll keep my fingers crossed for you!

I think it's no luck..we're losing a limb a day all leaves wilting and shriveling...this has all happened in about 3 weeks... Just before this happened, I had an arborist out who did a fertilizer into the ground all around all shrubs and trees..(VERY reputable arborist group)...but that couldn't have exacerbated the problem..could it? We're going to wait to cut down till next spring..just in case. Very sad.

I'm so sorry! But sometimes the lowest cut is the kindest - I'd hate to see you invest time and money babying a tree for a lifetime!

Well the maple is about 75% dead...we're going to cut it down as mentioned last year...any suggestions on a hardy tree for Chicago winters? thanks for all the info.

This website will help you choose a tree by exposure, use, size, tolerance, etc! http://urbanext.illinois.edu/treeselector/ These are also great: http://www.mortonarb.org/files/14CT_Northern%20Illinois%20Tree%20Species%20List.pdf and http://www.mortonarb.org/files/15CTP_Tree%20Selection%20Planting_BRCH_ReaderSpread_0331_sm-1.pdf