What disease first limited the use of Kentucky bluegrass?

• A. Melting out
• B. Take-all patch
• C. Pythium root rot
• D. Snow mold

Answer: (A)

Melting out is the disease that first limited the use of Kentucky bluegrass. This problem causes crowns to collapse and patches of dead turf under cool, wet conditions, so stands literally seem to “melt away.” In the early days of introducing Kentucky bluegrass, this rapid, patchy decline made it difficult to establish uniform, dependable turf, especially in climates with frequent wet springs or cool summers. The result was a clear and early limitation on how broadly Kentucky bluegrass could be used.

Snow mold tends to show up under snow cover in winter and is more of a seasonal reliability issue than an early factor in establishment. Pythium root rot targets seedlings and young plants, with problems mainly during establishment rather than long-term use, while take-all patch becomes a concern under certain soil and drainage conditions but didn’t historically curb the initial adoption of Kentucky bluegrass to the same extent as melting out.