By Gary L. Wade
and James T. Midcap
University of Georgia
The vibrant, snow-white flowers are showstoppers in the spring landscape. Then, as spring blossoms fade and other plants begin their summer growth phase, Summer Snowflake gears up for an encore performance. It flowers repeatedly throughout the summer and fall, often as late as November.
"It's a great transition plant," says Dottie Myers, an Atlanta landscape architect, "because it blooms when most other shrubs are done."
Planting tipsSummer Snowflake viburnum is a deciduous shrub, so it's best to plant evergreens nearby to mask its winter nudity. Little Gem magnolia, Henry Anise-tree or Japanese cryptomeria, three other Gold Medal winners from years past, are excellent companion plants.
Use Summer Snowflake as a single specimen or in groups of three to five plants for added interest in the landscape. It grows smaller and is more compact than many other viburnums, reaching 4 to 8 feet tall and 3 to 4 feet wide at maturity.
If Summer Snowflake viburnum has one flaw, it's a lack of drought tolerance. Water is essential during periods of limited rainfall. Drip irrigation will keep the plant looking its best.
But it's worth itSummer Snowflake's leaves are opposite, 2 to 4 inches long and 1 to 2 inches wide. It bears flowers in flat clusters 2 to 4 inches wide on top of the branches, giving the plant a layered effect.
Each flower cluster consists of many snow-white outer flowers surrounding a group of inner, less showy flowers. The flowers give way in late summer to clusters of bright-red fruit that fade to black. A wine-red leaf color signals the end to another growing season.
Few pests seem to bother Summer Snowflake viburnum. However, drought and wet feet will cause leaf scorching or dieback.
To look its bestMoist, well-drained soils are essential ingredients for success with Summer Snowflake. A full sun environment is ideal if irrigation can be provided during periods of limited rainfall. A place with morning sun and afternoon shade is OK, too.
Set plants 6 to 8 feet apart to allow them to reach their full potential as shrubs. Wait until they're well established before fertilizing. Then apply two to three light applications of a complete fertilizer, such as 16-4-8, during the growing season.
Prune the plants as needed after spring flowering by thinning excess branches within the canopy. Spring blossoms form on the previous season's growth. Repeat blooms form on new growth.
(Gary Wade and Jim Midcap are Extension Service horticulturists with the University of Georgia College of Agricultural and Environmental Sciences.)