Sixty cultivars of lilac obtained from two commercial nurseries were planted 18 May 1994 and immediately placed under drip irrigation and fertilized regularly. Powdery mildew appeared in July. Each plant was rated in July, August, and September for powdery mildew on a scale of 1 (healthy) to 5 (totally mildewed). There were 22 cultivars in the most resistant group (0–1.8) in July, 13 in August (0–1.0), and 11 in September (0–1.0). Mildew-free were: `Miss Kim', `Royalty', `Palibin', `Summer Snow', `White Summers', `Minuet', `Ivory Silk', `Anna Amhof', `Donald Wyman', but these were not significantly different from `James MacFarlane' and `Superba' (<10%of plant mildewed). Data on growth will also be presented.