Q: I have five edgeworthia plants. The one that has been most beautiful suddenly began to show wilt and appears to be dying. It gets morning sun and is in shade in the afternoon. Can you tell me what is killing it?
A: Paperbush, Edgeworthia chrysantha, is one of my favorite plants but sadly it is susceptible to Phytophthora root rot like its cousin Daphne odora.
In my experience, Phytophthora problems are caused by a plant growing in unaccustomed clay soil. Edgeworthia is a woodland plant, like azalea and rhododendron. They all demand highly organic, fast-draining soil. You can help woodland plants fight disease by adding plenty of soil conditioner to your clay soil before planting. Both composted hardwood and ground pine bark suppress root rot.
Remember that watering deeply once per week allows the soil to dry out between times and thwarts fungal growth. Try fertilizing with an organic nutrient source instead of synthetic fertilizer. Scatter a half-pound of cottonseed meal evenly under the branches of each plant in April after raking out all of the mulch. Replace the mulch with fresh pine straw.