My local diagnostic place is:
Cornell Cooperative Extension of Rensselaer County
99 Troy Road
Suite 203
East Greenbush, NY 12061
518-272-4210
I have attended a lot of workshops/classes sponsored by this Extension office. The staff are knowledgeable and very helpful. Today I called to sign up for Spring Garden Day, which is a yearly event organized by the Master Gardener volunteers. It is a full day of multiple class choices, a nice soup lunch, extensive book sale, plant sale, and prize give-aways. I signed up for native plants class, and unusual fruits for the garden.
At this location, I have also previously taken a workshop on pest identification, and a series of home-gardening once-a-week classes focusing on growing tomatoes, herbs, etc. Also, the Extension Agent there, David Chinery, has taught us how to identify turf pests and diseases.
In the past, I have sent garden and crop soil samples to the Cornell Soil Health Laboratory for diagnostics including pH and nutrient levels.
https://soilhealthlab.cals.cornell.edu/testing-services/
Also, I have talked with, and sent pest samples to, Dr. Timothy McCabe, who is the entomologist at the New York State Museum. He was very kind to help answer questions for young children about the insects they found.
timothy.mccabe@nysed.gov
A couple of years ago, I found a spotted lanternfly adult on my doorstep, and since it is an invasive that requires reporting of sightings, I made a formal report to the New York State Department of Environmental Conservation at:
https://survey123.arcgis.com/share/a08d60f6522043f5bd04229e00acdd63
My favorite books for identification/scouting are:
Encyclopedia of Trees and Shrubs by Michael Dirr… a huge tome that identifies trees and shrubs by many characteristics, lists propagation techniques, describes common pest/disease problems, and compares attributes of cultivars. This is NOT a lay-person book! I have had customers at plant sales literally pull it from my hands to read it, only to give it back with a disgusted look on their face. It is irreplaceable in the nursery trade.
Diseases & Pests of Ornamental Plants by Pascal P. Pirone… detailed descriptions of problems and what causes them… 584 pages
Weeds of the Northeast by Joseph M. DiTomaso, Richard H. Uva, Joseph C. Neal… full color pictures of weed seedlings and mature plants including seeds
I will post my greenhouse scouting update and weed identification separately.