Despite changing leaves, we haven’t hit fall yet [UPDATED]Published 3:57am Tuesday, September 3, 2013 Updated 5:58am Tuesday, September 3, 2013
We Minnesotans treasure fall with its cooler weather and beautiful fall colors. However, August is not fall, so why are some of the tree leaves turning color? Stress!
Actually, it is normal for some color this time of year. Shrubby sumac is quite red in many of the ditches and Virginia creeper, a vine is right on time for color change. Our native butternut tree will start coloring up as early as July, but if your maple is changing color, it’s in trouble.
Trees change color because the day gets shorter. Like fall blooming mums, who only start blooming when the days are shorter than the nights, trees start to color usually in last August or early September.
There are many things that can stress trees: disease, insects, storm damage, planting too deep and lack of water. Since we had a dry late summer and fall, many trees went into the winter short of moisture. They weren’t able to store up enough water to get through the winter. Dry soil freezes deeper and gets colder than damp soil damaging tree’s roots. If your suspect tree is on a hill, it can be because of gravity; water runs down hill and the tree didn’t get enough of it.
Another stressor is girdling roots. This can be the case of a container grown tree whose buyer didn’t inspect the roots before planting. The roots grow around the main stem of the tree which can cut off the flow of water eventually killing the tree. To prevent this costly mistake, dump the tree out of the container, shake or wash the soil off and untangle the roots or, if you can’t, cut off any that circle before planting. Plant with the top root only one to two inches below the soil.
Bev Johnson is a Master Gardener in Otter Tail County.