Calyx lobe tips are long, slender and very slightly pigmented. Corolla is small, pale lilac, or pale lobelia violet in center of each petal and white at edges. Anthers are empire yellow with pollen medium to poor. Tubers are oblong with a creamy buff smooth skin. Eyes are shallow except at apical end which is sometimes sunken.
Flesh color is white.
Ontario is highly scab resistant and has some resistance to late blight and Fusarium wilt. It has some tolerance to harvest bruising. It sets and sizes tubers late and maturity may be too late for regions with a short growing season. Vines are difficult to top kill. Tubers are susceptible to after-cooking darkening, particularly with late storage.