Anthracnose on Trees
We are starting to see anthracnose on sycamore, maple and ash leaves.
Other types of trees that can be affected by anthracnose include birch, elm, walnut, and oak. Sycamore is known to be prone to this disease and often shows symptoms with the greatest severity.
Anthracnose is a fungal disease that is favored by cool, wet weather.
Young leaves may wither and turn black. Older leaves may form brown areas that follow the major veins of the leaves.
In some cases, the petiole )leaf stem( is infected, which causes leaf drop. The leaf may look perfectly fine, so look for browned areas on the petiole.
In severe cases, the tree drops heavily infected leaves and may be completely defoliated. Normally, trees will leaf out again in a few weeks. Defoliation this early in the year does not affect overall tree health.
Trees have plenty of time to produce new leaves and make the energy reserves needed to survive the winter.
Because anthracnose seldom causes significant damage to Kansas' trees even when they are completely defoliated, chemical controls are unnecessary.
Also, fungicides do not cure infected leaves, and spraying after seeing symptoms is a waste of time and money. Therefore, applying fungicides now is not recommended.
Mowing and Watering — Do It Right
If I could identify two of the biggest problems in lawns in our area, they would come under the larger heading of mistakes made in mowing and watering.
Starting with mowing, most people try to mow their grass too short. There is a notion that if it is mowed short, they won’t have to mow as often.
So the grass gets tall and then it’s whacked off way to low. Tall fescue really needs to be mowed at 3½ inches and bluegrass at 3 inches.
Root development in grass is directly correlated to length of the leaf blades. More leaf blade makes more food within the plant and more food within the plant creates more roots to make your grass thicker and healthier and better able to withstand periodic dry weather.
Mowing short reduces vigor and root development, AND it opens up more soil surface to the sunlight. When you have sunlight reaching the soil surface, you will have weeds, period.
Remember, weeds are not a problem, they are a symptom of a problem. The problem is an uncompetitive stand of grass often caused by mowing too short.
Now, as for watering lawns......
There is no need to be watering your lawn until it dries out, warms up and actually starts to show some stress.
If you do water your lawn, do not water it a little bit every day. Give it one or two deep irrigations a week applied in the early morning.
Daily irrigations will keep the soil surface only moist, that’s where the grass plant will develop roots and then you have a problem.
Pratt, Kan. —
