Plant Health Care Report issue 2017-3

May 5, 2017

The scouting report of The Morton Arboretum for May 5, 2015.

PDF iconPlant_Health_Care_Report_2017_3 (PDF)



Bartlett Tree Experts, Presenting Sponsor of the Plant Clinic


Quick View

What indicator plant is in bloom at the Arboretum?
Horse chestnut (Aesculus hippocastanum) is in early flower

Accumulated Growing Degree Days (Base 50): 171.5 (as of May 4)
Accumulated Growing Degree Days (Base 30): 1326.5 (as of May 4)


  • Wise use of pesticides
  • Replacing ash trees (or just planning for an additional tree in the landscape)

Insects/other pests

  • Viburnum leaf beetle
  • Euonymus webworm
  • Boxwood psyllid
  • European elm flea weevil
  • Hackberry nipple gall psyllid
  • Pine bark adelgid
  • Slugs



  • Crown gall
  • Rust on buckthorn



  • Ficaria verna, a weed of many names