An early and a midseason cultivar of Jerusalem artichoke (JA) (Helianthus tuberosus) were better adapted than a late cultivar at Macdonald College and L’Acadie, Quebec, and Ottawa, Ontario. Diseases observed on JA were powdery mildew (Erysiphe cichoracearum), Sclerotinia rot (S. sclerotiorum), and apical chlorosis (Pseudomonas syringae pv. tagetis).Key words: Jerusalem artichoke, Helianthus tuberosus, adaptability, powdery mildrew, Sclerotinia rot, apical chlorosis