Since 1995, large numbers of oaks and tanoaks have been dying in California. Since then, many other types of plants have been found to be infected or associated with this disease, referred to as sudden oak death, ramorum leaf blight or ramorum dieback, or by regulation as Phytophthora ramorum. Since April 2004, the disease has been confirmed in  numerous West Coast counties. 

Kentucky has been identified as a high risk area for sudden oak death because of the extensive oak forests within the state.  This could have a severe effect on an economy that depends on the revenue generated from the sale of logs and wood products.  Detections in nurseries that ship widely throughout the United States have increased concerns that this disease could appear in other U.S. nurseries and hence move to susceptible species in the surrounding environment. To address these concerns and because of the potential and documented movement of the disease on nursery stock, we surveyed nurseries in Kentucky for the presence of sudden oak death (Phytophthora ramorum) as part of a national survey for this disease.

We inspected high risk genera (Rhododendron, Pieris, Kalmia, Camellia, and Viburnum) for symptoms such as foliar blight and shoot dieback. Samples taken from suspicious plants were processed at the University of Kentucky Plant Pathology Diagnostic Laboratory in Lexington, KY or the Pennsylvania Department of Agriculture Plant Pathology Lab, depending on the year.

Year	Number of Nurseries  Number of Trace Forwards (TF)	Plants Inspected Samples Tested All samples negative	Map
2024	18 nurseries 1 TF	Plants Inspected: 446 Samples: 70
2023	20 Nurseries 3 TF	Plants Inspected: 788 Samples: 79 TF Samples: 3
2022	20 nurseries 12 TF	Plants Inspected: 1,372 Samples: 80 TF Samples: 73
2021	20 nurseries 9 TF	Plants Inspected: 1,510 Samples: 68 TF Samples: 37
2020	24 nurseries	Plants Inspected: 2,282 Samples: 122
2019	25 nurseries 2 TF	Plants Inspected: 944 Samples: 111
2018	30 nurseries	Plants Inspected: 2,290 Samples: 165 Water Bait Samples: 6
2017	24 nurseries	Plants Inspected: 1,625 Samples: 98 Water Bait Samples: 8
2016	30 nurseries	Plants Inspected: 2,177 Samples: 126 Water Bait Samples: 17
2015	30 nurseries	Plants Inspected: 1,658 Samples: 123 Water Bait Samples: 18
2014	31 nurseries	Plants Inspected: 3,015 Samples: 164 Water Bait Samples: 20
2013	35 nurseries	Plants Inspected: 4,738 Samples: 284 Water Bait Samples: 20
2012	50 nurseries	Plants Inspected: 4,985 Samples: 255 Water Bait Samples: 34
2011	20 nurseries	Plants Inspected: 3,602 Samples: 114
2010	40 nurseries	Plants Inspected: 2,470 Samples: 197 Water Bait Samples: 29
2009	20 nurseries	Plants Inspected: 2,349 Samples: 93
2008	20 nurseries	Plants Inspected: 622 Samples: 91
2007	20 nurseries Samples from 19 additional nurseries	Plants Inspected: 3,057 Samples: 149
2006	21 nurseries Samples from 14 additional nurseries	Plants Inspected: 10,353 Samples: 190
2005	99 nurseries