The “Oklahoma Plum” refers to native wild plum species thriving in Oklahoma, primarily Prunus americana (American Plum) and Prunus angustifolia (Chickasaw Plum). These resilient native fruit trees offer ecological benefits and an edible harvest. They are known for their adaptability and ability to form dense thickets.
Identifying the Oklahoma Plum
Prunus americana, or American Plum, grows as a small tree or large shrub, reaching 10 to 20 feet with a broad, spreading crown. Its bark is grayish, becoming scaly with age, and branches often have a thorny appearance. The leaves are alternately arranged, broadly oval with sharply toothed edges, measuring 2 to 4 inches long, and are dark green above with a paler underside.
Prunus angustifolia, known as Chickasaw Plum, presents as a shrub or small tree, usually growing 4 to 15 feet tall, though it can reach 25 feet. Its young stems are reddish, sometimes featuring thorn-like lateral branches. Bark is initially smooth, becoming scaly and shallowly furrowed as the plant matures. The leaves are narrow, oval-lanceolate, bright green, and 1 to 3 inches long with finely toothed margins.
Both species produce small, five-petaled white flowers in early spring before leaves fully emerge. The fruit of Prunus americana is round, about 1 inch in diameter, ripening from red to yellow in late summer, with succulent but often tart flesh. Prunus angustifolia produces smaller, cherry-like fruits, 0.5 to 1 inch in diameter, which are red and ripen to yellow from June to July. They are known for their sweet pulp, though can be tart until fully ripe.
Natural Habitat and Ideal Growing Conditions
These native plum species thrive across a wide range of habitats in Oklahoma and central North America. They are found in open woodlands, along stream banks, pastures, old fields, fencerows, and disturbed sites, often forming dense thickets.
For cultivation, both American and Chickasaw plums prefer well-drained soils, adapting to light (sandy), medium (loamy), and heavy (clay) types. They tolerate a range of soil pH from mildly acidic to mildly alkaline. Full sun to partial shade is suitable; full sun promotes better fruit production. While they prefer moist soil, they are drought-tolerant once established. Both species are winter-hardy: Prunus americana tolerates temperatures as low as -50°C (USDA Zone 3), and Prunus angustifolia is hardy in USDA Zones 5-9.
Cultivating and Caring for Oklahoma Plums
Planting Oklahoma Plums is best done when dormant, late fall or early spring. These plants are known for their suckering habit, spreading by root sprouts to form thickets. Consider this for spacing. If a single tree form is desired, regular removal of suckers is necessary. Initial watering is important for establishment, particularly in drier conditions.
Pruning maintains shape, improves air circulation, and encourages fruit production. For American Plum, prune dead or diseased branches and thin dense growth. Chickasaw Plum can be pruned to improve crown form, though it tends to sprout from the base. Fertilization is not required for these native species, as they are adapted to local soil conditions.
Oklahoma Plums can encounter common pests and diseases. Plum curculio and brown rot affect fruit; leaf spot, canker, and black knot impact foliage and branches. Aphids, scale, borers, and tent caterpillars may be observed. Good air circulation through pruning, monitoring for early signs of infestation, and removing infected plant parts help manage these concerns.
Uses and Ecological Benefits
Oklahoma Plum fruit is versatile. While plums can be eaten fresh, their tartness, especially from Prunus americana, often makes them better suited for cooking. They are processed into jams, jellies, pies, and preserves. The fruit ripens from late summer to early fall, offering a seasonal harvest.
Beyond culinary uses, these native plums offer ecological benefits. They provide food for wildlife, with fruits eaten by birds, deer, and small mammals. Dense, thorny thickets offer cover and nesting sites for songbirds and small animals.
Flowers are an early-season nectar source, attracting pollinators like bees and butterflies. Their extensive root systems are effective for erosion control and soil stabilization, particularly on slopes or stream banks. They also serve as windbreaks or natural barriers in landscaping.