What Is a Beach Plum?

The beach plum, or prunus maritima, is a deciduous shrub in the plum family. It is native to North America, where it is found growing along the Atlantic coast. Sand dunes are the natural habitat of the beach plum, and thriving plants are sometimes seen half-buried in sand. These plants grow along the seashore from Maine to Maryland. The beach plum is considered endangered in Maine, where it is losing habitat due to intensive, commercial coastal development.

Beach plum plants thrive in bright sun and sandy soil with good drainage. They usually spread by underground suckers, but sometimes increase by tap roots, depending on the type of soil. Beach plums are commonly used to stabilize seaside sand dunes and control erosion because of their deep, spreading root systems. Although they are native to the seashore, these plants can also do well when cultivated inland in well-drained soil.

This fruiting shrub tolerates salt water and cold temperatures. It grows in thickets 3 to 7 feet (1 to 2 meters) high, but can grow as tall as 17 feet (5 meters) high when cultivated in a garden. The oval leaves are 1 to 3 inches (3 to 7 centimeters) long and ¾ to 1.5 inches (2 to 4) centimeters wide, and appear after the flowers have bloomed. Plum tree leaves alternate along branches that may bend under the weight of clusters of fruit that resemble large grapes. Its leaves are a vivid green on the top, and have pale green undersides.

The beach plum produces attractive blossoms that grow in clusters in the spring. Its flowers have five petals which are white until after pollination, when they develop a pinkish hue. The blooms have long, protruding stamens with large, yellow anthers on their tips. Plums ripen towards the end of summer and attract birds. These plums are stone fruits, which can be substituted in recipes for other stone fruits such as cherries and domesticated plums.

Ripe beach plum fruit is round and approximately ½ to ¾ inches (1 to 2 centimeters) in diameter. Before it ripens, the plum is hard with a red color and bitter taste. The ripe plum is purple or blue and commonly used to make cordials, wines, jellies, jams, and baked goods. A cottage industry has been developed in the northeast to market this tasty fruit. Harvested in colonial days for use in jams and jellies, the beach plum has become popular fare today in Atlantic seaside spas, restaurants, and resorts.