Trees - Elm

Foliage diseases: Anthracnose, black spot and powdery mildew. Black spot and powdery mildew can cause premature leaf shedding. Although fungicides are approved to control these foliage diseases, seldom are symptoms observed in time to apply effective treatments.

Like all elms, cedar elm trees are susceptible to the bacterial disease slime flux. The bacteria causes a fermentation of the tree's sap. This results in pressure in the tree and a brown sap flows from weak crotches or old wounds on the tree's limbs or trunk. It is the most resistant of the elm trees to the soil borne disease cotton root rot.

Slippery Elm (Ulmus rubra) is an elm that is frequently found in the Texas Hill Country but is limited to soils along streams. It is moderate in height reaching around 40 ft. and has a trunk diameter of 6 inches. The top is wide spreading. Growth rate is moderate. it should not be planted in upland soils.

Foliage diseases: Anthracnose, black spot and powdery mildew. Seldom are fungicides suggested.

The trees are also susceptible to slime flux and Dothiorella twig die back. It is also one of the more susceptible cultivars to cotton root rot.

American Elm (Ulmus americana) is an excellent tree for the landscape. When mature it reaches a height of 60 ft. and has a trunk diameter of 3 ft. The trees have an upright growth habit. it requires a somewhat deep soil. For maximum growth. It has not been widely planted because of its susceptibility to Dutch Elm Disease. This has destroyed many of the American elms in other areas of the United States. Recently there have been trees diagnosed as having Dutch Elm Disease in East Texas and also just south of the Red River in North Central Texas.