Hello and thank you for contacting Ask Extension. I think you both might be right. Yews are typically very hardy plants, and are not susceptible to many diseases. However, several stress factors can cause yews to turn brown. One of those stress factors is winter damage. Winter injury occurs as a result of rapidly changing temperatures during the winter, bright sunshine, and inadequate water reserves in the root system of the plant. Plants usually show the first symptoms of winter injury in late winter through spring, and browning is most pronounced on the south and west sides of the plants. Although foliage turns brown, if buds remain green and viable, the plant may recover as the spring progresses.

Yews are quite sensitive to deicing salts used on roadways and sidewalks. Plants that have been affected by these salts typically turn brown starting from the side closest to the area salted. Symptoms usually first appear in the spring. When salts have washed into the soil under a yew, leaching the soil with a large amount of water may help.

Wounds to the bark of branches can also cause portions of yews to turn brown. Such wounds can be caused by animals or inadvertent injury by people. Yews are not very tolerant of wounding. From your pictures it looks like the top of many of the outside branches have been nibbled off, possibly by deer. The branches closest to the house are not nibble off and are still green so I believe this may be your problem.

Yews also don't like "wet feet" and can develop root problems if their roots are kept too wet. Although considered relatively drought-tolerant, too little water can also cause problems. Choosing an appropriate, well-drained site for the yew and watering during very dry periods is the best defense against these problems.

When yews turn brown, their site and recent history should be reviewed to determine a cause. Yews affected by salts or winter damage may recover over time, and it is wise to not prune out the brown tissue immediately in case the branch tips are still viable.

Here are some suggestions to reduce winter injury on yews:

• Plant yews on the north and northeast sides of buildings or in areas protected from wind and winter sun.
• Prop pine boughs or Christmas tree greens against or over evergreens to protect them from winter wind and sun.
• Construct a barrier of burlap or similar material on the south, southwest, and windward sides of evergreens. If a plant has exhibited injury on all sides, surround it with a barrier, but leave the top open to allow for some air and light penetration.
• Keep evergreens properly watered throughout the growing season and into the fall. Never stress plants by under or over watering. Decrease watering slightly in September to encourage hardening off, then water thoroughly in October until the ground freezes.
• Do not prune after August as pruning can induce the growth of new foliage.
• Anti-desiccant and anti-transpirant sprays are not effective for protecting evergreen foliage.

Brown needles will not green up. But the buds are still viable, they will often grow and fill in the dead areas.

• Wait until mid-spring before pruning out injured foliage.
• If the buds have not survived, prune dead branches back to living tissue.
• Fertilize injured plants in early spring and water them well throughout the season.
• Provide appropriate protection the following winter.

The best way to protect your yews from deer browsing is to use physical barriers to prevent them from getting to your plants. There are also repellents you can spray on your plants but they need to be reapplied after rain or irrigation. Granular forms are also available that can be sprinkled on the ground. Both of these are available at your local garden center.

Here are some links to articles that may help you bring your yews back to life.

https://www.canr.msu.edu/news/winter_brings_evergreen_damage

https://yardandgarden.extension.iastate.edu/article/2006/5-17/yew.html

https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter#how-to-reduce-evergreen-winter-injury-1264311