Japanese Snowball Viburnum plicatum f. plicatum Newport = 'Newzam'

Water

Newport Viburnum requires consistent moisture for optimal growth, particularly during its first few growing seasons. It's best to water this plant deeply once a week, providing it with about 1-2 inches of water each time; this would be approximately 0.62-1.25 gallons for a small shrub. During hot or dry weather, you may need to water twice weekly to maintain the soil's moisture, but always check the soil beforehand to ensure it is not already saturated. Reducing watering frequency to every two to three weeks is usually sufficient during the cooler months. Make sure to water at the base of the plant to keep the foliage dry and prevent any potential disease spread.

Light

Newport Viburnum thrives in locations that receive full to partial sunlight, ideally around six to eight hours of direct sun per day. It can tolerate some shade, particularly in the hotter afternoon hours, so planting it where it can get morning sun and afternoon shade is beneficial. Avoid deep shade areas, as insufficient light can lead to poor flowering and weak growth.

Temperature

Newport Viburnum is hardy and can tolerate a range of temperatures. It prefers to grow in zones 5 to 8, with the ideal growing temperatures ranging between 60°F and 75°F. It can survive minimum winter temperatures down to -20°F once well-established. To maintain healthy growth, try to avoid exposure to extreme heat above 95°F for prolonged periods.

Pruning

Newport Viburnum benefits from annual pruning to maintain its shape, improve airflow, and encourage more vigorous growth and better flowering. The best time to prune this viburnum is immediately after it finishes flowering in late spring to early summer. During pruning, remove any dead or damaged branches and thin out older stems to rejuvenate the plant. Depending on the desired shape, light shaping or more formal pruning can be performed at this time.

Cleaning

As needed

Soil

Japanese Snowball 'Newzam' prefers well-draining soil with a rich organic content; a mix of loam, peat moss, and perlite would be ideal. The soil pH should be slightly acidic to neutral, ranging between 5.6 and 7.5.

Repotting

Japanese Snowball 'Newzam' does not commonly need repotting as it is typically grown as a landscape shrub; however, if planted in a container, it should be repotted every 3-5 years to replenish the soil and provide room for growth.

Humidity & Misting

Japanese Snowball 'Newzam' thrives in average outdoor humidity levels; it does not have specific humidity requirements, making it adaptable to various outdoor conditions.

Suitable locations

• Indoor

  Place in bright, indirect light and rotate periodically.

• Outdoor

  Plant in partial shade, ensure moist, well-drained soil.

• Hardiness zone

  5-8 USDA

Life cycle

The life cycle of the Viburnum plicatum f. plicatum 'Newport', also known as Japanese Snowball, begins with seed germination, where environmental conditions such as temperature and moisture trigger the emergence of a new plant from a seed. The seedling stage follows, characterized by the growth of roots, a stem, and embryonic leaves, which will develop into true leaves capable of photosynthesis. As the plant enters the vegetative stage, it focuses on growth, developing a robust root system and a fuller canopy through a process of branching and leaf production. The plant reaches maturity in the reproductive stage, where it produces characteristic white, globe-shaped flowers clustered in snowball-like formations, which are pollinated by insects and potentially capable of setting fruit in the form of small red-to-black berries if cross-pollinated. After pollination and fruit set, the plant enters a period of senescence yearly, where older leaves and potentially some branches die back, usually coinciding with colder weather. However, as a perennial, the plant will return from dormancy in the following growing season, repeating the cycle of growth, flowering, and senescence for many years.

Propogation

• Propogation time

  Early Spring

• The most popular method for propagating the Viburnum plicatum f. plicatum 'Newport', also known as the Newport Flowering Viburnum, is through softwood cuttings. This technique is best carried out in late spring or early summer when new growth is still flexible but also mature enough to survive on its own. To propagate by softwood cuttings, one takes a cutting about 4 to 6 inches (approximately 10 to 15 cm) long from a healthy branch, ensuring there are several leaf nodes present. The cutting's lower leaves should be removed, and the cut end dipped in rooting hormone powder to encourage root development. Afterward, the cutting is planted in a well-draining potting mix and kept in a humid environment with indirect sunlight until roots have formed, which usually takes several weeks. Regular misting during this time helps prevent the cutting from drying out. Once the new plant has established a sufficient root system, it can be transplanted to its final location.