Hello,

Yews are hardy plants that are not susceptible to many diseases. However, there are conditions which may cause the needles to turn brown, including poorly draining soil, improper fertilization, winter burn and winter salt damage. Read more here: https://yardandgarden.extension.iastate.edu/article/2006/5-17/yew.html

And here: https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/yew-problems

And here: https://www.canr.msu.edu/news/winter_brings_evergreen_damage#:~:text=Browning%20needles&text=Salt%20may%20get%20on%20evergreens,eventually%20it%20melts%2C%20salt%20included.

Because these are older plants, winter damage could be the culprit. Yews do not tolerate wet soils—has an unusual amount of water, perhaps from a faulty eavestrough been falling on the plants over the winter? When evergreens are pruned and the temperature increases the hot sun may burn the tender new buds.

The plants are showing plenty of new growth. Properly keep them watered (not too much) and they will recover.

To properly identify what agent is at fault, send a picture or sample to MSU Extension’s Plant and Pest Diagnostic Lab at: https://www.canr.msu.edu/pestid/.

Thank you for contacting Ask Extension.