Japanese snowball trees (Viburnum plicatum) are likely to win a gardener’s heart with their lacy white globes of flower clusters hanging heavy on the branches in spring. These large shrubs look like they could require a lot of maintenance, but Japanese snowball care is really quite easy. Read on for more Japanese snowball information, including how to plant a Japanese snowball tree.
I. Appearance and Characteristics
Viburnum plicatum is a species of flowering plant in the family Adoxaceae (formerly Caprifoliaceae), native to mainland China, Korea, Japan, and Taiwan. The Latin specific epithet plicatum means “pleated”, referring to the texture of the leaves.
Growing to 3 m (10 ft) tall, it is a deciduous shrub. The leaves are opposite, 5–10 cm (2–4 in) long and 3–6 cm (1–2 in) broad, simple ovate to oval, with a serrated margin.
Plants from Taiwan are sometimes distinguished as Viburnum plicatum var. formosanum Liu & Ou.
The flowers are produced in flat corymbs 5–10 cm (2–4 in) in diameter, comprising a central cluster of fertile yellowish-white flowers 5 mm (0.20 in) in diameter, surrounded by a ring of showy, sterile flowers 2–3 cm in diameter, which act as a target guide to pollinating insects. The fruit is an ovoid blue-black drupe 8–10 mm long.
Viburnum plicatum is a popular ornamental plant, both in its native area and other temperate regions. Some of the more popular cultivars are selected for having all of their flowers large and sterile with few or no fertile flowers; their flowerheads resemble a snowball, giving them the popular name Japanese snowball bush. Cultivars of this type include ‘Grandiflorum’ and ‘Rotundifolium’.
II. How to Grow and Care
Japanese snowball flourishes best in well-drained, moderately fertile soil, preferring locations with partial to full sunlight. Special care points include providing Japanese snowball with sufficient moisture, especially during dry spells, and pruning after flowering to maintain its attractive shape and promote healthy growth. Japanese snowball is considered generally low maintenance, making it a suitable choice for both novice and experienced gardeners.
Sunlight
Japanese snowball in a cold environment loves to grow in full sun on slopes and edging rocks in its natural habitat. Varieties adaptable to warmer climates grow well in full sun to medium shade; long exposure to strong light should be avoided. They can be shaded by buildings or big trees. A certain amount of scattered light is needed in the flowering phase to ensure enhanced and continuous flowering in warmer climates, but overall, plants in this genus perform well receiving 5-6 hours of continuous sunlight in a day.
Temperature
The optimum growth temperature range is between 5 to 27 ℃. It has good cold resistance; some native North American species can tolerate temperatures below -25 ℃. Its growth is poor at temperatures above 29 ℃, so it cannot survive in tropical summers. Germination requires 20 consecutive days of seed exposure to 24 ℃.
Japanese snowball needs occasional watering during hot and dry conditions. The average plant during its first 2 years of growth needs 1.2 to 1.5 cm water bi-weekly. Once established, it doesn’t need much watering.
Watering
Originating from regions with moderate climates, japanese snowball has adapted to withstand periods of lower water availability, making it relatively drought-tolerant. Its natural resilience translates into a preference for watering once every 1-2 weeks, ensuring the soil moisture levels are consistent without being waterlogged. Typically grown outdoors due to its size and ornamental value, japanese snowball thrives in well-draining soil that complements its need for balanced moisture during its active growing season.
Soil
Japanese snowball likes fertile, soft, slightly acidic soil with good drainage. It likes moist soil but does not grow well in waterlogged soils. It can grow in moderately fertile, fully drained soils that keep minimum moisture, but cannot withstand poor soil. The optimum soil pH range is 5.5-6.6. It can tolerate acidic media and drought with good air circulation in the root zone, which is made possible by the addition of peat moss or coco coir to the media. The best potting soil would be to mix 1 part of fully decomposed organic matter into 2 parts of garden soil.
Fertilizing
For optimal health and blooming, fertilize Japanese snowball in early spring with a balanced fertilizer. A slow-release formula ensures steady nutrient uptake. Monthly applications during growing seasons bolster vigor, but cease in fall to prevent new growth susceptible to frost. Use manufacturer guidelines for quantity, adjusting for plant size and soil fertility. Over-fertilization can harm, so be precise. During dormancy, Japanese snowball requires no feed. Regular soil tests help maintain fertility without excess. Incorrect application risks root burn; always water before and after fertilizing.
Planting Instructions
- Start by choosing a border, pot or container in a position that benefits from 2-4 hours of sunlight a day to plant your Viburnum plicatum in. Ideally, this position will benefit from morning sun and evening sun, rather than the stronger midday sun
- Once you have found your position, make sure that the soil is well-draining. If your soil is not, you can add sand or gravel to create drainage
- Dig a hole that’s 2-3 times as wide and deep as the roots. Add your root ball to the soil and backfill with the soil removed. Tamp the soil around the plant and settle in by watering
- If you are planting multiple Viburnum plicatum or neighboring plants, give 1m of space between each to allow their roots and top growth to spread. While your Viburnum plicatum is established, water 2-3 times per week.
Pruning
Light pruning to remove dead or dried branches or injured parts of the plant can be done at any time of the year. Japanese snowball doesn’t need severe pruning; how much depends on the type of variety and purpose of growing.
Pruning to shape and beautify can be done in the late winter or early spring. When growing for borders and hedges, cut only 1/3 of the branches if they are severely intermingled. In other cases, pruning can be initiated right after flowering but before the setting of fruit. To avoid frost damage, don’t prune during frost or severe cold.
Propagation
Japanese snowball is known for its attractive, rounded blooms and layered branches. To propagate japanese snowball, softwood cuttings are the most practical way to ensure successful rooting. Carefully select healthy, non-flowering shoots in late spring or early summer. Cut a 4-6 inch section, strip the lower leaves, and dip the cut end into rooting hormone powder to enhance root development. Plant the cutting in a well-draining potting mix, maintaining consistent moisture and warmth. A protective environment, like a plastic cover, can provide the necessary humidity.
Transplanting
The perfect timing to transplant a Japanese snowball is during the latter part of spring when active growth begins. Choose a semi-shaded location with well-drained soil for its new home. Remember, gentle and consistent care is key for a successful transplant.
Repotting
When repotting a Japanese snowball, a bushy deciduous shrub, choose early spring or after it blooms in late spring. Repotting every 2-3 years due to its moderate growth rate. Select a container a size larger with ample drainage to accommodate root development. Post-repotting, ensure the Japanese snowball is in partial shade and maintain moist soil to foster recovery and thriving growth.
Pests and Diseases
No serious insect or disease issues. Keep an eye out for aphids, scale insects, thrips, or viburnum beetles. Occasional disease problems include leaf spot and powdery mildew. Apply appropriate treatments as needed.
III. Uses and Benefits
Due to its ornamental features, Japanese Snowball is often used in mixed borders, as a standalone specimen, or even as a flowering hedge.
