Toothache Tree (Zanthoxylum americanum) is a native deciduous shrub or small tree that belongs to the citrus family, not the ash family as its common name might suggest. Growing 15 to 20 feet tall and equally wide, this aromatic, spiny plant thrives in hardiness zones 3 to 7 and earns its name from the numbing sensation its berries and bark produce when chewed, a property that made it valuable to indigenous peoples and early settlers for dental relief. This Missouri native colonizes naturally in rocky hillsides and open woods, tolerating poor soils and drought while attracting butterflies and birds with its showy fruit and fragrant spring flowers. It's an exceptionally hardy ornamental that doubles as a living piece of natural history, thriving in full sun to partial shade with minimal fuss once established.
Partial Sun
Moderate
3-7
240in H x 180in W
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High
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The spiny foliage and fragrant April blooms catch the eye, but the real draw is the showy fruit that follows, paired with the plant's genuine hardiness in cold climates and its tolerance for poor, rocky soils where many trees struggle. Giant swallowtail butterfly caterpillars feed on prickly ash, so you're not just growing a tree; you're supporting a critical part of the local butterfly life cycle. Freely spreading via root suckers, it naturally forms dense thickets and handles drought once established, making it a low-maintenance choice for naturalistic gardens or difficult sites.
Traditionally, the berries and bark were chewed or prepared as a remedy for toothaches, leveraging their numbing properties. Today, the plant primarily serves as an ornamental tree in native plant gardens, wildlife gardens, and naturalistic landscapes where its spiny structure, fragrant spring flowers, and showy fruit are appreciated for their aesthetic and ecological value. It also functions as a crucial host plant for giant swallowtail butterfly larvae.
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Prune Toothache Tree in late winter or early spring to manage the dense thicket growth and root sucker formation, or to maintain a more tree-like form rather than allowing it to spread into a shrubby mass. Remove any dead or crossing branches, and thin the canopy if needed for air circulation. The spiny stems require careful handling during pruning.
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“Zanthoxylum americanum is a native Missouri plant documented as occurring naturally on bluffs, upland rocky hillsides, open woods, and moist ravines across its range. Indigenous peoples and early settlers discovered the numbing properties of its berries and bark and used them for toothache relief, a folk remedy that earned the plant its enduring common name. This connection between the plant and its practical use, passed down through generations, anchors the Toothache Tree in American natural and cultural history as a plant people knew and valued long before ornamental landscaping became common.”