October 10, 2007
An occasional sight in late summer, especially in southern Iowa, is the accumulation of small broken twigs on the ground under oak, hickory and other shade, nut and fruit trees. The foliage at the ends of twigs turns brown prematurely before the twigs fall to the ground. The dropped twigs that look like they were neatly cut from the tree as with a pruning shear are the work of the twig girdler, Oncideres cingulata.
Garden mums (Chrysanthemum x morifolium) often don't over-winter well in Iowa. Repeated freezing and thawing of the soil during the winter months can heave plants out of the ground and cause severe damage or even death. Damage is most likely in poorly drained soils.
Sulfur shelves are one of the most noticeable fungi. The bright yellow to orange lobed fruiting body, composed of many overlapping shelves, may be up to a foot in diameter. Sulfur shelves can be found growing on a large variety of deciduous and coniferous trees, both living and dead. The most common species of sulfur shelf is Laetiporus sulphureus. Shelves grow directly from the trunk of a tree, without stalks, and tiny pores on the undersides of the shelves produce spores. Shelves typically appear in the summer or fall.