Zone Recommendation for a Waterfall Cascading Japanese Maple

Winter Hardiness

• The Waterfall Japanese maple survives winter low temperatures that plummet to minus 15 degrees Fahrenheit, correlating to U.S. Department of Agriculture plant hardiness zones 5b through 8. In zone 5, it's best to plant any Japanese maple in a wind-protected location so frigid, drying winds in winter do not cause twig dieback.

Sunset Climate Zones

• Particularly in the western United States, the USDA zone designations are not always effective in predicting plant performance due to variable elevations. Instead, an alternative zone system was developed by "Sunset Magazine." Sunset climate zones take temperature, soil, wind, rainfall, elevation and latitude into consideration to inform gardeners which plants do best in any specific area. Grow the Waterfall Japanese maple in Sunset climate zones 2 through 10, 12 and 14 through 24 in the western U.S. and in zones 31 through 41 in the eastern United States.

Heat-Zones

• The American Horticultural Society developed a zone map based on the number of days of temperatures at or above 86 degrees Fahrenheit each year. Know as the AHS Heat-Zone Map, 12 zones across the U.S. reveal areas where the summers are especially hot. All Japanese maples, including cultivar Waterfall, are naturally woodland plants and need cool, more humid summer settings to truly prosper. Grow them in heat-zones 8 and cooler, where no more than 120 days of temperatures over 86 F occur. This heat limitation prevents Waterfall from growing well in the Southwest deserts and in the Deep South along the Gulf of Mexico.

Growing Conditions

• Plant Waterfall Japanese maple in an acidic, humus-rich soil that is always evenly moist but well-drained. These maple trees develop fibrous, shallow roots that are quickly stressed from hot or dry soil. Cover the soil with organic mulch and maintain it at a depth of 3 to 4 inches. Irrigate during the first 12 months after planting to establish a good root system and irrigate older trees during periods of extended drought. In cool summer regions, it may tolerate full sun, but farther south, all-day sun causes browning of leaves and increases the need for irrigation. In hot summer climates, plant Waterfall in partial shade settings, with full shade during the hottest part of the afternoon.