Content by John Ball

hand holding three green apples with a dimpled, lumpy appearance

Apple Issues

Learn to identify and manage common apple tree issues including: apple maggot injury, apple scab, cedar apple rust, and fruit cracking.

An ash tree branch with ash flower gall damage.

Ash flower galls are appearing on the twigs of ash throughout the state. The brown to black “balls” hang in clusters beneath the branch shoots. The galls are due to the feeding activity of the ash flower gall mite (Eriophyes fraxiniflora) and this mite only feeds on the male flowers of ash.

Aphids On Trees

Aphids are appearing on many trees at this time of year and their activity is generally noticed by the abundance of honeydew they excrete on the lower leaves and any plants or objects beneath the tree.

A sample of green leaves with noticable bumps at their bases.

Cottonwood Galls

Just about every year I receive samples of fallen cottonwood leaves with a “bump” at the base and the first one for this year was from Winner. This is the cottonwood petiole gall formed by the feed activity of a very small green aphid.

spruce tree seedling with weeds beneath it

Weeds Around Spruce Seedlings?

I have many producers call wanting a control for the broadleaf weeds coming up around their young Colorado and Black Hills spruce seedlings. At this time of year we are looking at post-emergence herbicides to control weeds that have become established.

ash leaves with orange to yellow gall-like spots

Tree Rust Diseases

Ash rust and crown rust are two common rust diseases that impact South Dakota trees.

apricto leaves with several small holes throughout

Shot Hole Disease in Apricots

Shot hole disease of apricot trees can be identified through symptoms on leaves and fruit. Small holes will appear on leaves while brown lesions with a deep purple band will show up on fruit.

Trees growing in an re-purposed feedlot.

Trees for Abandoned Feedlots

Finding trees to plant over former feedlots or surrounding existing ones is not an easy task.

Common Ash Borers, Bark Beetles, and More

Green ash is still one of the most commonly planted trees in South Dakota, and considering the number of trees in windbreaks, along urban streets, and in yards already, it is a surprise anyone would think we need more. In addition to the numerous pest problems we already have with this tree, the looming threat of emerald ash borer should make us a little more cautious about wholesale recommending the use of this tree.

Sawyer Beetles and Pine Wilt Disease

A sample came in from a recently felled Scotch pine tree down in Southeastern South Dakota. The hole and sawdust is due to a sawyer beetle that had infested the tree.