Strawberry farmers face two serious diseases caused by a water-mold pathogen: crown rot that kills the whole plant and leather rot that spoils the fruit. Scientists sequenced the DNA of different disease-causing strains to understand why some strains can infect only fruit while others destroy the entire plant. They found that highly virulent strains have specific genetic changes in genes that help the pathogen escape the plant’s immune system, which could help develop better disease control strategies.