Home and Landscape

Phytophthora Root and Crown Rot (Red Stele) on Strawberries

  • Phytophthora spp.

Phytophthora root and crown rot may appear anytime during the season, and is first seen as stunted growth or wilted young leaves. Wilting spreads to the rest of the plant and some leaves may turn reddish. Crown tissue is discolored brown or reddish brown. Wilted plants eventually collapse and die. Stunted plants usually remain stunted for the rest of the season.

Identification

Phytophthora crown rot can be distinguished from other diseases by the appearance of crown tissue discoloration and decay. The decay usually starts at one point on the crown and spreads around the crown until the entire plant is girdled. The roots may remain healthy. If the diseased crown is sliced open, the affected area appears water soaked and uniformly brown; the discoloration is not confined to the vascular tissue.

Solutions

Root and crown rots tend to become problems when planting beds remain wet for prolonged periods. This is most likely to occur in heavy soils or if planting beds are watered excessively or too frequently. Root and crown rot can be minimized or avoided by preparing raised beds with well-drained soil, providing good drainage away from planting beds during rainy weather, avoiding overwatering, and replacing plantings every few years. Where the disease has developed, soil treatments including solarization can be used to reduce Phytophthora levels before replanting strawberries.

For more information, see the Phytophthora Root and Crown Rot Pest Note.

Sliced open crown tissue, showing darkening of diseased crown (below) compared to healthy crown; Sacramento; Credit: Jack Kelly Clark, UC IPM
Brown discoloration of crown tissue. Credit: Jack Kelly Clark, UC IPM
Brown leaves of young plant on white plastic mulch; Kelly Ranch test site for methyl bromide alternatives Credit: Jack Kelly Clark, UC IPM
Discolored and wilted strawberry plant. Credit: Jack Kelly Clark, UC IPM
Dark roots and crown and lack of healthy feeder roots (left) compared to healthy plant (right); Sacramento; Credit: Jack Kelly Clark, UC IPM
Healthy (left) and infected (right) plants. Credit: Jack Kelly Clark, UC IPM
The pesticide information on this page may become out of date as products and active ingredients change or become unavailable. Some of the pesticides listed are only available for use by licensed pesticide applicators. No endorsements of named products are intended, nor is criticism implied of products not mentioned.