My caryopteris shrub is slowly 'fading' -- leaves on a branch go limp and then die. Does it have a disease; if so, how do I treat it? Or could it be from the harsh rain and wind we had several weeks ago?
If you had a lot of rain, then it could simply need time to dry out some. It may even have developed a fungal infection as a result. You can cut away any unhealthy branches and treat the shrub with neem oil or other suitable fungicide.
I cut the dead wood back in the center when it was leafed out - in May - there are no flowers at all and many of the leaves are yellowing the plant is about 4 year old help
So, the center of the plant was dead in spring. Do you mean regular winter kill? Did you remove more than half the plants leaves? You may have just really stunted its growth for this year. Make sure it is getting enough water and only use a side dressing of compost, not fertilizer. Caryoptersis blooms in late summer to early fall. It is said to tolerate summers in zone 9 so if you are having a zone 10 type summer, it may be heat stressed.
When is the best time to plant the Longwood Blue Blue Mist Shrub? Thank you.
You can plant in spring or fall.
https://www.gardeningknowhow.com/ornamental/shrubs/blue-mist-shrub/caryopteris-blue-mist-shrubs.htm
I live in zone 5: I have a Bluebeard Caryopteris which was planted last summer. It only shot up one branch during that growth period. It has wintered over very nicely. What should I do this spring? When do I cut it back and do I continue to pinch out growing tips to encourage a bushy growth habit?
The shrub will probably die back to several inches from the ground. If you watch the plant, you'll see buds start to swell. Cut it down to the live buds - 5-6 inches from the ground. Those buds should develop into branches. If it flowered last year, you may find seedlings nearby! However, if your bluebeard is a cultivar, seedlings will not look exactly like the parent plant. https://www.gardeningknowhow.com/ornamental/shrubs/blue-mist-shrub/caryopteris-blue-mist-shrubs.htm
The die back occurs most winters, sometimes as much as 3/4 of the bush. I cut the dead out and by late summer It has filled out and bloomed. It gets about 6 -7 hours of sun and is in a border planting with larger shrubs behind it. I do not water it. We generally get adequate rainfall. It's ugly in the spring and beautiful by September.
This is normal behavior from the shrub. Here is an article with more information:
https://www.gardeningknowhow.com/ornamental/shrubs/blue-mist-shrub/caryopteris-blue-mist-shrubs.htm