Erik I would go to the garden center and ask or look around for a liquid form of root stimulator. I use a product called Laters"Root Booster". I`m sure you will find something similar there. The product really helps with any transplant shock. Washy`s don`t really need it as much as other finicky palms. They just grow so much better with it.Another suggestion would be soil high in perlite for fast drainage,but you already knew that. Hope this helps.

John