Plum (Prunus domestica) — identification, habitat & look-alikes

Plum, also known as European plum, is the fruit tree behind the classic dried prune. It is grown in US orchards and backyards, and in parts of New England it has escaped to roadsides and old homesites. White spring flowers give way to fruit that can be blue-black, red, yellow, or green depending on the variety. It is also called prune plum.

Appearance

Growth form: A small tree or large shrub, usually 10–20 ft (3–6 m) tall, with thin, smooth bark and usually no thorns.
Leaves: Elliptic to obovate leaves about 1½–4 in (4–10 cm) long, with rounded teeth along the edge and fine hairs along the veins underneath.
Flowers: White, five-petaled flowers open in early spring, before or with the leaves, singly or in pairs.
Fruit: A fleshy fruit 1½–3 in (4–7.5 cm) long with a flattened, ridged pit that usually comes free from the flesh. Fruit is typically ready around September.

Look-alikes

Cherry-plumPrunus cerasifera

Cherry plum fruit is small and round, about 3/4–1¼ in (2–3 cm) across, and many planted trees have purple leaves. European plum fruit is much larger, about 1½–3 in (4–7.5 cm) long.

Why they get mixed upBoth have white spring flowers and plum-like fruit, cherry plum is common in yards, and it is considered a parent of the European plum.

American plumPrunus americana

American plum is a native shrub or small tree that often spreads into thickets, with flowers in clusters and small red-to-yellow plums in midsummer. European plum flowers come singly or in pairs, and its fruit is larger and juicier.

Why they get mixed upBoth are white-flowered plums that can turn up along roadsides and field edges.

PeachPrunus persica

Peach flowers and fruit sit almost directly on the twig, and the fruit is fuzzy. Plum flowers and fruit have clear stalks, and the fruit skin is smooth.

Where it lives

Typical habitats: Orchards
Gardens
Roadsides and old homesites
Range: Thought to have arisen in the Caucasus region and now known almost only in cultivation. It is not native to North America; in New England it has been recorded growing wild in Connecticut, Massachusetts, and New Hampshire.
Preferred conditions: Full sun and fertile, moist, well-drained soil. Because it blooms early, a spot sheltered from late frost and cold wind helps. Hardy in USDA zones 4–9.
Seasons: In the US
Fruit Sep

Growing it

Propagation: Usually grafted; it can also be grown from root cuttings or seed.
Toxicity: Listed as a problem plant for dogs, cats, and horses.

Name and classification

About the name: Long thought to be a natural hybrid of sloe (Prunus spinosa) and cherry plum (Prunus cerasifera), which would explain its six sets of chromosomes. Some later studies suggest cherry plum alone may be its wild ancestor.
Varieties and forms: There are many varieties, including prune types that dry well with the pit inside, round yellow mirabelles, and small, tart damsons. Greengages (Reine Claude) are treated as their own subspecies, Prunus domestica italica.

Conservation

IUCN Red List: DDData DeficientNot enough data yet to assess
Threats: Common orchard problems include codling moth, plum curculio, borers, and diseases such as brown rot and powdery mildew.