Photo: Ryan Watson, CC BY 4.0 · Wikimedia Commons

Swamp Tupelo

Nyssa biflora

Also called swamp blackgum, Nyssa sylvatica var. biflora.

A tupelo for southern swamps and pond edges, with a swollen base, red fall color and spring flowers that bees make into tupelo honey.

Tolerates wet soilHoney treeFall colorWildlife value

Type: Large tree
Mature height: 60–80 ft
USDA zones: 6–9
Growth rate: Medium
Sun: Full, Part
Soil moisture: Average, Wet
Grows wild in: Floodplain forests, stream banks, swamps and wet flats
Native range: 17 states, north to New Jersey, south to Florida and west to Texas
List all 17
Alabama, Arkansas, Delaware, Florida, Georgia, Illinois, Kentucky, Louisiana, Maryland, Mississippi, Missouri, New Jersey, North Carolina, South Carolina, Tennessee, Texas and Virginia
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Swamp tupelo is the wetland cousin of black gum, and many botanists long treated it as a variety of that tree. It has narrower, leathery leaves, carries its female flowers in pairs, and swells at the base where it stands in water. A 2018 genetic study found its line has been apart from black gum's for 11 to 13 million years. The Apalachicola River bottoms of west Florida produce large amounts of swamp tupelo honey from its flowers. It belongs at a pond edge, in a wet swale or in a seep that stays wet all year.

Size, growth and what to expect

Swamp tupelo grows at a medium pace, about a foot and a half a year in our growth estimator. Dominant trees averaged 36 feet at 20 years and 65 feet at 50. Expect 60 to 80 feet with a narrow crown 20 to 40 feet wide. Sprouts from a cut stump have borne seed at 2 years.

Small greenish flowers open with the leaves from April into June, and bees are their main pollinators. The dark blue fruit, about half an inch long, ripens from August to October and falls through December. Robins and other birds eat the fruit and spread the seed.

It grows wild on the Coastal Plain from Delaware south to southern Florida and west to eastern Texas. It reaches up the Mississippi valley to southern Arkansas and western Tennessee. Its home is headwater swamps, ponds, river bottoms and estuaries that flood for much of the growing season.

How to grow Swamp Tupelo

Swamp tupelo wants full sun or part sun and a wet, acid soil of muck, clay or sand. It grows best where the soil stays saturated under shallow, slowly moving water, and still water in a pond can cut its growth by as much as half. Plant it 20 feet from a wall and more than 50 feet from overhead wires, and set trees 30 feet apart.

Saplings ship potted. The long taproot makes an older tree hard to move, so plant it young and leave it in place. Plant in the dormant season, in a hole wider than the pot and deep enough for the taproot. Set the root flare at the soil line, put the native soil back in, and mulch a wide ring clear of the trunk. Clean the pulp off the seed and hold it damp in the refrigerator for 30 to 120 days. Sow it in spring, half an inch deep, and keep the bed moist but not flooded. Untreated seed can also go into an outdoor bed in fall.

Water weekly through the first summer unless the ground stays wet. A seedling dies if a flood covers it for long while it is growing, though a winter flood does no harm. Deer find the seedlings and sprouts very palatable, so cage young trees for the first several years.

Trees are male or female, and only females bear the dark blue fruit, so plant three or more seedlings for a male and a female. Forest tent caterpillars and the tupelo leaf miner attack the leaves and can slow growth. It is very prone to sapsucker damage and is readily hurt by salt spray. The leaves turn red in fall.

Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.

Sources (12)