August Leaf Color Change On Many Of The Large Poplars

Many of the membership have approached me in the last month about the obvious early leaf loss on many of the large poplars on the golf course. I had a theory and did some research on the subject. Without going into great detail I then called Verna Mumby of Mumby Tree Services. She is our professional consultant that knows the trees here better than anybody and a well respected voice in tree care throughout Western Canada.

It is as I suspected. Basically nothing to get too concerned about. I'll list the variables in point form and then detail Verna's thoughts.

Consider the following:

• Poplar roots span out across many of our fairways.
• The fairways were subjected to many flood events this past summer thus the root systems had a very healthy supply of water in many locations.
• The poplars are the tallest trees on the course and were subjected to the high winds associated with the many thunderstorms we had in June and July.
• Temperatures were quite warm as well.
• Northwest poplar are not usually susceptible to conditions such as Bronze Leaf. That disease is more common in Swedish aspen and columnar poplars. Our poplars are so large they can generally "brush off" many diseases, blights, insects, etc.

All of the above can lead to early leaf loss. Many of you noticed what appeared to be a mold or fungus on the leaves on the trees or on the ground. Keep in mind that when the leaves are changing color they are basically cut off from life support. They are dead or dying and decomposition is underway, hence maybe some fungus or mold. 

If you have read all of the above and understand things to this point here is where it all comes together.

Trees spend most of the summer building up energy to survive the coming winter. A large part of that energy is used in the production of new buds (usually in August) for the next growing season. Once those buds are ready the tree begins the process of leaf removal. That usually occurs a few weeks later than we saw this season but the poplars had their buds formed earlier than usual (in late July) due to the above mentioned points. They were well fed, healthy and ready to "shut down" in late August instead of early to mid September. Not all the poplars responded in the same manner. Environmental conditions across the golf course are varied so the timing of leaf change and loss will also be varied. Just as we are seeing at present. Verna believes we have nothing to be concerned about.

I hope this blog topic has been informative and put some minds at ease. I know the poplars looked great before the early leaf loss began so I'm optimistic that things are alright.

By the way, we are topdressing the last 3 fairways today and that finishes the aeration process in 6.5 work days. The great weather helped even though there were a few hiccups and a few muddy fairways on Tuesday. Thanks for your patience over that last couple of weeks.

Wade