Self-seeded trees and shrubs dying off this year?
Thank you for contacting "Ask an Expert." I have polled a number of Master Gardeners and Horticultural professionals and still don't have a definitive answer for you. The question is broad and to begin to attempt to answer it would require a more information. What plants (specifically) are affected? Are/were they established plants or young plants? What are the symptoms? Are they all in the same area?
This past winter was particularly difficult for a lot of plants. Some didn't recover as well as could be expected and others had an incredible flourish of growth.
If you can get some samples of the plants' leaves which exhibit the pests or symptoms I would recommend that you bring them to the local Extension office so they can our diagnostics team can take a look.
Again - thank you for using our service. Please let us know if you need any further assistance.
UDNCC Master Gardener