I live in Southeast Oklahoma. I would like to have my wisteria a deep purple. At present it is light lavender. Is there something I can add to the soil to manage this on my own?
Certified GKH Gardening Expert
Unfortunately, there is no way to change the color of the wisteria. If it is a variety that is light purple, it will stay light purple and you will need to plant a new, darker flowered variety to get the color you like.