Use caution when planting to be sure that planting stock is not infested. If yard soil is contaminated, plant shrub in a large container of sterilized soil. This is probably the most serious problem experienced by althea. Althea is very susceptible to attack by the cotton root rot fungus that occurs in the soils of central Texas. If this disease is a problem in the area, it may be necessary to grow the plant in a large container of sterilized potting mix or soil.
Infection is characterized by yellow-orange pustules on the lower leaf surface.
Fungicide control is usually not necessary.