The “horns” that give Horned Oak Gall their common name are popping through the surface of the galls in southwest Ohio. The horns are just the tip of the iceberg with this gall-making wasp. They also produce leaf galls.

An invasive species is an organism that is not native to a defined location and did not evolve in that present ‘new’ environment and therefore has few to no natural enemies. Often this organism can out compete native organisms, and therefore can become a problem by throwing nature out of balance. Examples of invasive species can be found in all classes of organisms including plants, animals, insects, and microorganisms. Two examples of invasive insects that will have a major impact in Ohio are Spotted Lanternfly and Box Tree Moth. We will look at how fast these population can grow.

Participants in the “Diagnostic Challenge” held during the 2026 Ohio Forest Health in Columbus this past week observed tiny Elm Leafminer Sawfly adults (Fenusa ulmi (= Kaliofenusa ulmi), family Tenthredinidae) bagged in Southwest Ohio. The tiny, shiny-black adults look like gnats on steroids, buzzing around the leaves of their namesake host.

Poison Hemlock and Wild Parsnip are beginning to “bolt” in southwest Ohio. This means it’s time to apply selective or non-selective postemergent herbicides to manage these dangerous non-natives. Both belong to the carrot family Apiaceae (= Umbelliferae)) and both present serious human health risks, but in very different ways

Spring is in the air but don't let the warm days trick you into planting annual flowers and vegetables to early.

A weekly summary of horticultural happenings and reports from across Ohio for the week of March 31, 2026.

The Spring 2026 Buckeye Turf Newsletter is now available online. This edition includes seasonal guidance, applied turfgrass research updates, and timely management recommendations from the Ohio State Turfgrass Team.

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As the diagnostic season begins to ramp up, we are seeing a steady increase in sample submissions and a growing diversity of plant health issues. The following is a brief summary of diagnostic activity from January through March, highlighting key trends in crops, disorders, and pathogens observed during this early part of the year.

This Week's Observations

Pest Identification

Several insect specimens found in homes were presented for identification, including:

• A small (1–2 mm) strawberry root weevil. These are "accidental invaders" that do not burrow into wood or reproduce inside homes, but do feed on a wide range of weeds outdoors. Read more at this MSU link for Strawberry root wevil.
• A mysterious larva that could not be...

This Week's Observations

Diagnostic Issues

• Canaan Fir Tip Blight.  The diagnostic lab received Canaan fir samples showing tip dieback with Phomopsis/Diaporthe spores identified. The fungus is likely opportunistic, triggered by environmental stress (rain → drought cycles, cold, transplant stress). Stress likely predisposed seedlings, but is not considered ...