(Red Horsechestnut)
SIZE: Medium (Height: 20-35'; Spread: 20'-30').
GROWTH RATE: Slow.
FOLIAGE: Dark green serrated, palmate leaves with five oval leaflets, 4-8" long. New foliage is yellow-green. Fall foliage is yellow; tree is bare November-March.
FLOWER/FRUIT/BARK: Soft pink to red bell-shaped flowers in showy clusters on 8" stalks, bloom April-May. Hard, slightly prickly seed capsules, about 1" diameter, form in late summer. Slightly rough, dark gray bark.
MONTHLY WATERING NEEDS: In general, 15-20 gallons per week for the first 2 years; 15-20 gallons twice a month for the 3rd year; as needed after 3 years (varies by soil, sun, and wind conditions).
TREE CARE: Moderate. Requires occasional pruning, sidewalk clean-up during flower drop.
TOLERANCES: Prefers full sun or partial shade. Sandy or clay soils. Special Considerations: Uneven performance in San Francisco, leaves look burned much of the year. Does best in warmer areas of the city, does not tolerate wind. Needs extra water in sandy soils or hot or windy conditions. For good performance, needs monthly watering during dry months throughout lifetime. Susceptible to powdery mildew and leaf spot. Seeds slightly toxic if ingested. Notable Traits: Hybrid between eastern US (Aesculus hippocastanum) and European species (Aesculus pavia). Striking red flowers attract hummingbirds. Good under overhead wires.
ALTERNATE FORMS: 'Briotii' has rosy crimson flowers, 'O'Neill Red' has single flowers of bright red.