Editor's note: Due to unfavorable weather conditions, the elm tree spray at University Park originally scheduled for July 17-18 has been delayed by one day and will now take place during the evening of Tuesday, July 18, and the morning of Wednesday, July 19. Updated details about the spray are provided below.

UNIVERSITY PARK, Pa. — The Penn State Office of Physical Plant (OPP) will conduct the second part of its annual elm tree spraying July 18-19 at the University Park campus to combat Dutch elm disease and elm yellows.

Ground-based spraying will begin at 10 p.m. Tuesday, July 18, and end at approximately 3 a.m. on Wednesday, July 19. Aerial application by helicopter will take place from approximately 4-7 a.m. on Wednesday, July 19. Both aerial and ground-based applications are weather-permitting. Signage will be posted in the affected areas, and ground support crews will be present.

OPP sprays the elm trees each year in May and July to slow the spread of Dutch elm disease and elm yellows and protect the remaining iconic elms on the University Park campus. These applications are carefully timed to best control the pest and benefit the trees, while being as minimally invasive as possible to the campus community and the trees’ diverse ecosystem.

OPP thanks the campus community for understanding the need to spray the trees and cooperating with this important program aimed at preserving the campus’ elm trees.