Additional photographs for the original question

We viewed your photos. This does not look like boxwood blight. https://extension.umd.edu/resource/boxwood-blight

We see some symptoms of volutella, a fungal disease https://extension.umd.edu/resource/volutella-blight-disease-boxwood and some leafminer damage, an insect. This is normal on boxwood and can be controlled through pruning. https://extension.umd.edu/resource/boxwood-leafminer-shrubs

We also see lichen (pale blue-gray residue on the bark) which is harmless. They can appear or increase in number on branches which are dead or dying due to the increase in light levels on the wood (since there are fewer leaves shading it). They may also grow on a mature slow growing plant. https://extension.umd.edu/resource/lichens

The round nodules on the branches looks like dead/aborted ripe seed pods. They look old and ready to fall off. This is not a problem. 

 No chemical controls are recommended. The boxwoods need to be thinned back into shape, not sheared.  At this point, we recommend that you prune out the dead/affected foliage when it is dry. Remove old fallen leaves and diseased leaves that have accumulated in the branch crotches. Thin the boxwoods to improve air circulation and light penetration. See the above link for a pruning video and how to manage and diagnose boxwood problems. 

Also, it looks like your boxwoods are located in full sun. In general they prefer some afternoon shade. They have a shallow root system so water during dry periods and make sure mulch is no thicker than an inch or two  and away from the base of the plants. https://extension.umd.edu/resource/boxwood-diagnose-manage-and-prevent-common-problems

Marian 

Dear Marian,

Thank you again [you may recognize my earlier pleas for help on other matters] for your knowledge and terrifically helpful answers and attendant links.  I will follow through as you have directed and start watering them regularly to atone for the ever hotter direct sunlight.

I do have some more related questions regarding feeding. What about fertilization? Does the addition of fertilizer help boxwoods? Would foliar feeding be beneficial?

Thank you,

John

• Boxwoods need well-drained soil and will not tolerate sites that are constantly moist. Do not overwater. 
  

Fertilizer is not a remedy for landscape problems. Get your soil tested if you expect a nutrient deficiency.  The plant will only uptake what it needs and overfertilized plants are susceptible to sucking insects. Here is our page on soil testing https://extension.umd.edu/resource/soil-testing-and-soil-testing-labs

https://extension.umd.edu/resource/fertilizing-trees-and-shrubs

Marian

You are welcome.

Marian