Newport Plum (Prunus cerasifera newportii)

Plant Snapshot

Common Name: Newport Plum
Latin Name: Prunus cerasifera newportii
Hardiness Zones: USDA zones 4–8 with reduced winter damage in warmer zones and increased cold stress in colder zones
Typical Height: About 15–25 ft (4.5–7.6 m) at maturity
Typical Spread: About 15–20 ft (4.5–6 m) spread
Bloom Period: Early spring (typically March–April in the Northern Hemisphere)
Soil Preferences: Well drained soils preferred. Adapts to a range including heavier soils. Prefers fertile loam and neutral to slightly acidic pH
Light Preferences: Full sun for best flowering and leaf color. Tolerates light shade but may be less floriferous and lose leaf intensity
Toxicity: Leaves, stems and pits contain cyanogenic compounds. Ingestion of crushed pits or large amounts can cause cyanide poisoning in people and pets. Ripe fruit flesh may be edible but pits are toxic
Propagation: Grafting onto plum rootstock is standard to preserve cultivar traits. Seeds will not reliably produce the same cultivar. Nurseries also use budding and cuttings

Key Facts

Ornamental purple leaf plum grown for foliage and early spring flowers
Small to medium deciduous tree commonly used as a specimen or in groupings
Early spring single pale pink to white flowers appear before or with the leaves
Performs best in full sun for strongest leaf color and heaviest bloom
Prefers well drained soil and tolerates a range of soil types including heavier soils
Grafted plants retain cultivar traits while seed grown plants may not come true
Typical mature height about 15–25 ft (4.5–7.6 m)
Parts of the plant contain cyanogenic compounds and pits are poisonous

The Newport Plum (Prunus cerasifera newportii) is an ornamental purple leaf plum grown for dramatic foliage and early spring flowers. It performs best in full sun and well drained soil and makes a strong small to medium specimen or grouped focal point while carrying the tradeoff of cyanogenic pits that are poisonous.

Identification

This small to medium deciduous tree typically reaches about 15 to 25 feet tall with a similar spread. Leaves are purple and showiest in full sun. Single pale pink to white flowers appear in early spring before or with the leaves, creating a brief display that contrasts with the dark foliage.

Best uses and where to grow

Use Newport Plum as a specimen in small to medium gardens or plant several as a mixed border group for repeating color. It suits urban and suburban landscapes where a compact ornamental tree is needed. Avoid planting where dropped pits could be a hazard for children or pets.

Planting time and spacing

Plant in spring or fall when soil is workable and risk of extreme heat or cold is low. Allow space at least equal to its mature spread of about 15 to 20 feet between trees to avoid crowding and to let the canopy develop naturally. Set the root ball at the same depth as it grew in the container.

Soil light and watering

Full sun gives the strongest leaf color and the heaviest bloom while light shade will reduce intensity and flowering. Choose a well drained site and fertile loam if available. Poor drainage reduces vigor and raises risk of root problems. Water regularly during the first season to establish roots and then water as needed during extended dry spells.

After flowering care and pruning

Prune after flowering to shape the tree and to control spread while avoiding removal of next season’s flower buds. Light formative pruning helps maintain a single trunk or multi stem form. Remove any dead wood and thin congested growth to improve air movement and light penetration.

Propagation

Nurseries usually graft the Newport cultivar onto plum rootstock to preserve its purple leaf trait. Budding and cuttings are also used commercially. Seed will not reliably produce the same cultivar so seed propagation is best reserved for rootstock or breeding rather than for true to type plants.

Pests and toxicity

Parts of the plant contain cyanogenic compounds and pits are poisonous if chewed. Ripe fruit flesh of some plums can be edible but always remove pits before offering fruit to children or pets. Monitor for general Prunus health issues and keep fallen fruit and debris cleared to reduce problems.

Frequently asked questions

How fast does Newport Plum grow?: Growth rate varies with site and rootstock and depends on climate and care. Expect it to reach its typical 15 to 25 foot mature height over several years under favorable conditions.
Is Newport Plum hardy?: It is generally hardy in USDA zones 4 to 8 with more winter damage possible in the coldest areas and faster growth in warmer zones.
Are the fruits edible?: Some plum flesh can be edible but pits contain cyanogenic compounds and are poisonous if chewed. Remove pits before serving fruit to people or pets.
How should I propagate Newport Plum?: Propagate cultivars by grafting or budding onto plum rootstock to retain purple leaf traits. Cuttings and commercial methods are used but seed will not come true to type.
How close can I plant two Newport Plums?: Allow at least the tree’s mature spread between trunks about 15 to 20 feet to prevent canopy crowding and to reduce competition for light and root space.