In our small garden in central Toronto, several boxwood bushes are getting discoloured, dry leaves. Some have visible insects, especially on underside of leaves. A photo is attached. How can I deal with these problems? A photograph is attached below.
Thank you for whatever advice you can offer.
Most affected areas receive about 5 hours of sunlight.
Thank you for contacting Toronto Master Gardeners with your question.
Unfortunately the picture isn’t attached. Your description confirms that your boxwoods are attacked by Boxwood Leafminer (Monarthropalpus flavus). The leafminer is the larva (immature form) of a small, orangish mosquito-like fly. Here is a link to a previous Toronto Master Gardener post on ‘time to deal with boxwood leaf miners’, which you may find informative: https://www.torontomastergardeners.ca/time-to-deal-with-boxwood-leaf-miners/
Good luck!