Photo: Krzysztof Ziarnek, CC BY-SA 4.0 · Wikimedia Commons

Gum Bumelia

Sideroxylon lanuginosum

Also called gum bully, woolly buckthorn, woolly bumelia, gum elastic, Bumelia lanuginosa.

A thorny native tree for dry, rocky ground, with fragrant white flowers in early summer and shiny black fruit that birds eat into winter.

Drought tolerantWildlife valueShowy flowersStreet tree

Type: Small tree
Mature height: 15–45 ft
USDA zones: 5–10
Growth rate: Medium
Sun: Full, Part
Soil moisture: Dry, Average
Grows wild in: Rocky ground, dry uplands, stream banks, sandy barrens, old fields and edges
Native range: 15 states, north to Illinois, south to Florida and west to Arizona
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Alabama, Arizona, Arkansas, Florida, Georgia, Illinois, Kansas, Kentucky, Louisiana, Mississippi, Missouri, New Mexico, Oklahoma, South Carolina and Texas
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Gum bumelia is a thorny native tree of the sapodilla family, whose tropical sapodilla tree gave chewing gum its chicle. Cut its bark and a milky sap oozes out, and the Kiowa and Comanche chewed a substance from the outer bark as gum. It grows in dry, rocky woods, glades, fencerows and old pastures, and along streams. In Missouri it is the last tree to bloom, save the fall-flowering witch hazel. Illinois, at the north end of its range, lists it as endangered. It suits a street with no sidewalk, or a highway median. Plant it along a property line, in a shelterbelt or on a dry, stony bank that gets little care.

Size, growth and what to expect

Gum bumelia grows at a medium pace, about a foot and a half a year in our growth estimator. Expect 15 to 45 feet with a crown 10 to 30 feet wide. Wild trees reach 18 meters, or 59 feet. On poor soil in the wild it grows slowly and stays stunted.

Clusters of small, fragrant white flowers open in June and July. The fruit, a shiny black berry up to half an inch long, ripens in September and October and hangs on into winter. Birds eat it, and people can too, but more than a little brings a bellyache.

It grows wild from South Carolina and northern Florida west to southern Arizona and northern Mexico, and north to southern Kansas, Missouri and southwestern Illinois. It is deciduous in the north of its range and evergreen in the south.

How to grow Gum Bumelia

Gum bumelia grows in full sun or part shade, in any soil that drains well, rocky ground included. It takes clay, sand, acid or alkaline soil, and once established it stands long droughts. Its winter hardiness is not well documented, so at the cold end of its range give it a sheltered spot. Plant it 15 feet from a wall and more than 50 feet from overhead wires, and set trees 20 feet apart.

Saplings ship bare-root or potted. Plant them dormant, from leaf fall until bud swell, in a hole wider than the roots and no deeper. Set the root flare at the soil line, put the native soil back in, and keep the mulch clear of the trunk. Clean the seed from fruit picked as soon as it turns purplish black. Chill it damp in the refrigerator for 60 days, and sow it in spring under a light cover of soil. It sprouts slowly, and tested lots came up at 21 to 44 percent.

Water every week or two through the first summer, then only in a long drought. Deer browse the leaves and fruit, so cage young trees for their first few years. Left alone, a young tree grows into a shrubby ball, so choose one leader early for a tree form. Wear gloves when you prune, since the branches carry sharp thorns.

Each flower carries both male and female parts, so there are no male and female trees to pair. Bees visit the flowers. It has no serious pests or diseases.

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

Sources (9)