Q.shrubs
One of my Capitata yews is starting to get yellow needles. These are very expensive plants. I want to prevent it from dying. What is your suggestion?
The yellowing needles could be water issues, mineral deficiencies, insects, or or a fungus.
Make sure the shrub is not in overly wet soil and that the area is well draining. The Yew is tolerant of most soil conditions except wet soil.
Root rot will cause yellowing needles.
The Yew prefers soil that is a ph of 6.0 to 6.5. Adding chelated iron to the soil can help.
Lack of magnesium can also cause yellowing needles. You can use magnesium tablets or a fertilizer with magnesium in it.
A soil test can help you correct soil nutrient issues.
Black Vine Weevils, scales and mealybugs attack Yew's. Search for insects and treat with Neem Oil if you find these bugs.
https://www.gardeningknowhow.com/ornamental/shrubs/yew/growing-yew-shrubs.htm
