I have vincas planted under a juniper tree. Their leaves are yellowed. I can't get them to grow or green up. Any advice?
Certified GKH Gardening Expert
Too much sun and too much water can cause the leaves to yellow and if the conditions persist, the plants can suffer root rot.
Vinca prefer to grow in dry conditions.
The links below will refresh you on the care requirements.
I also included a link that lists the most common diseases in Vinca.