Our presumed dead wisteria began growing again a couple of years ago, and we were so excited we forgot to notice it was growing between deck boards. I suppose the two "trunks" are now about an inch in diameter. But the top is wonderful, covering the pergola like crazy. No flowers but the shade is what we wanted anyway. The bark got "skinned" on one of the "trunks", so I read up and somewhere I saw a thing that said wash with mild soap and rinse well and leave the rest to the lord. Another site said cover it with orange shellack (spelling?). We NEED this shade and don't know what to do. Please advise.
Wisteria Trunk Damage
Certified GKH Gardening Expert
Do not use the orange shellack. That will seal the wound, but could also seal disease and fungus into the wound.
The mild soap is a good idea, but I would actually take it one step further and say to treat the wounds with fungicide. The big worry with an open wound on a plant is that fungus will get into the wound and harm the plant. Soap and water is good to prevent this, but a fungicide is better.
It is wisteria and they are notoriously hard to kill, so I would not be too worried if I were you... But, just in case, you may want to also preemptively treat the plant with a pesticide. Stressed plants (such as ones whose bark has been damaged) are more susceptible to pest infestations. If you treat a stressed plant now, it can prevent more stress from pests later.