Q.The flower buds on my pieris japonica have all turned brown over winter.
What is causing them to dry up before opening in the spring? The plant was covered with buds last fall before all turning brown.

Certified GKH Gardening Expert
There are a few things that could be the issue here.
They need yearly fertilization. Lacking in phosphorus and potassium can cause a problem with flowering. They also need acidic soil, so make sure that you are feeding them with and acid lovers blend. Calcium and magnesium can be lacking in acidic soil, so supplementing a little bit can help has well.
This article will help: https://www.gardeningknowhow.com/ornamental/shrubs/japanese-andromeda/grow-japanese-andromeda.htm