Ask Mr. Smarty Plants

Purple Sage, Leucophyllum frutescens is also known as Cenizo, Texas Ranger, Texas Sage, Barometer Bush and Silverleaf. It is a tough-as-nails shrub native to south Texas.

Purple Sage is highly resistant to most insect pests and diseases. However, it is susceptible to Cotton Root Rot (Phymatotrichopsis omnivora) in poorly drained soil, in over-watered landscapes or during wet seasons. Once Cotton Root Rot, also known as Texas Root Rot, has infected one plant in a landscape, the pathogen stays in the soil and will infect other susceptible plants that replace it. The much-used Red Tip Photinia, Photinia xfraseri is particularly susceptible to Cotton Root Rot and is responsible for many of the occurrences of the disease that we see.

To positively identify Cotton Root Rot, it is best to pull a dead plant out of the ground, shake off as much soil as possible away from your landscape, and take the plant -- roots and all -- to your county agriculture extension office. For more information on this particularly pernicious fungal disease, see this article on Diseases of Urban Landscapes.