Hello, we have 5 boxwood around the turret of our house and they all seem to be suffering from a bug or fungus or something else. Some of the leaves are covered with very small little white dots, and make the leaves look not as true green as others. Some interior leaves are turning yellow and falling off. Sometimes when I'm watering I notice that very teeny tiny white bugs are flying around .
Montgomery County Maryland
Your boxwood leaves have stippling spots from boxwood mites. Scroll down on this page for information: https://extension.umd.edu/hgic/topics/boxwood-preventing-and-managing-common-pests-and-diseases
If you decide to apply a horticultural oil or soap, follow label directions very carefully regarding air temperature so it does not burn the leaves.
The yellowing leaves may be due to stress. May was fairly dry. They may need watering during dry spells. Or this could simply be old leaves dropping off, which is normal.
Be sure mulch does not touch the base of the plant (or any plant). Keep it back a few inches.