Where Does Sassafras Grow? Its Range and Habitat

Sassafras (Sassafras albidum) grows natively across a broad swath of eastern North America, from southwestern Maine south to central Florida and west to eastern Texas, with outposts reaching into southern Ontario and central Michigan. The tree thrives in disturbed, well-drained sites with moderate sunlight, and its ability to colonize old fields and forest edges makes it one of the more recognizable pioneer species in the eastern deciduous forest. But sassafras is not just a North American tree. The genus contains three species spread across two continents, and the pressures shaping where each one grows are shifting in real time.

The North American Range

The USDA Forest Service maps sassafras from southwestern Maine west through New York, extreme southern Ontario, and central Michigan, then southwest through Illinois, extreme southeastern Iowa, Missouri, southeastern Kansas, eastern Oklahoma, and eastern Texas, and back east to central Florida.¹ That footprint covers most of the eastern United States, from the Gulf Coast nearly to the Canadian border. The tree is absent from the Great Plains and the Rocky Mountain West, where conditions are too dry and winters too harsh in the northern stretches.

Within that broad range, sassafras is not evenly distributed. It is most common in the central Appalachians, the Piedmont, and the upper South, where it frequently turns up in second-growth forests, along roadsides, and at the edges of agricultural land. It becomes less common toward the northern and western margins of its range. Sassafras was once present in southeastern Wisconsin but is now considered extinct there, while at the same time it has been extending into northern Illinois.¹ Range edges are dynamic, not fixed lines on a map.

Habitat Preferences and Growing Conditions

Sassafras is flexible about soil but has clear preferences. It does best in moist, well-drained, sandy loam soils that are slightly acidic. Heavy clay that stays waterlogged will usually kill it. You can find it on ridgetops, hillsides, and in bottomlands, but it tends to be most vigorous on middle and lower slopes where drainage is good and moisture is moderate. It tolerates a range of soil fertility and is not particularly picky about pH, though strongly alkaline soils are unfavorable.

Light is arguably the biggest factor shaping where sassafras shows up. The tree is moderately shade-tolerant when young but increasingly intolerant as it matures. Seedlings can survive in partial shade for a few years, but sustained growth requires canopy gaps or open conditions. This is why sassafras is so strongly associated with disturbed sites: roadsides, abandoned fields, powerline cuts, and forest edges all provide the light it needs. In a closed-canopy mature forest, sassafras gradually loses out to more shade-tolerant species and either dies back or persists as an understory shrub.

This light requirement also helps explain why sassafras responds well to fire. Prescribed burns open the canopy, and sassafras seedlings in burned areas produce two to three times the total leaf area of seedlings on unburned sites, a response linked to the greater canopy openness that burning creates.² Fire does not just help sassafras survive; it gives the tree a competitive advantage by removing the overhead shade that would otherwise suppress it.

How Sassafras Spreads and Persists

One of sassafras’s most distinctive traits is its aggressive clonal reproduction. While the tree does produce seeds (small, dark-blue drupes carried by birds), vegetative spread through root sprouting is often the primary way sassafras populations maintain and expand themselves. Horizontal roots send up new shoots, sometimes at considerable distances from the parent trunk, creating what looks like a grove of individual trees but is genetically a single organism.

A detailed genetic study of a one-hectare sassafras stand identified just 31 genetically distinct individuals, or genets. Some of those clones were enormous: the largest comprised over 100 stems (ramets) and spanned more than 8,000 square meters.³ Clonal richness was low, meaning the vast majority of stems in the plot were clonal copies rather than seedlings that had established from seed.³ Different clones were extensively intermingled, so the grove looks random to the eye even though it is structured by underground root connections.

The root buds responsible for this clonal spread are not all created equally. Some are preformed in the root tissue and sprout as part of the tree’s normal expansion strategy. Others form in response to damage, sprouting from root cuttings or after the main stem is killed.⁴ This dual strategy means sassafras can spread steadily outward in good times and bounce back quickly after disturbance. It is one reason the tree is so persistent once established: you can cut it, burn it, or bulldoze it, and the root system will almost certainly send up new shoots.

Sassafras in Old-Field Succession

If you have ever driven through the rural Southeast or mid-Atlantic and noticed a wall of sassafras saplings colonizing an abandoned pasture, you have seen one of the tree’s signature ecological roles. Sassafras is a classic early-successional species, among the first woody plants to move into open land after farming stops. But unlike many pioneer trees that fade quickly as the forest matures around them, sassafras has a chemical trick that lets it hang on longer than expected.

Research in Tennessee found that sassafras uses allelopathy to suppress competing plants. The tree releases chemical compounds from its roots and leaf litter that inhibit the germination and growth of neighboring species. This allows sassafras to maintain relatively pure stands through multiple stages of old-field succession, far longer than a typical early-successional species would normally persist.⁵ Eventually, shade-tolerant hardwoods do replace it, but the allelopathic effect buys sassafras extra decades on the landscape.

Combined with its clonal growth, this chemical defense explains a pattern that surprises many people: sassafras stands that seem permanent in areas that were open farmland within living memory. The underground root network keeps expanding, the allelopathic compounds keep suppressing competitors, and the result is a dense, aromatic thicket that can dominate a site for a generation or more.

A Three-Species Genus on Two Continents

Most people think of sassafras as a single North American tree, but the genus actually contains three species distributed across eastern North America and East Asia, a biogeographic pattern known as a disjunct distribution.⁶ Sassafras albidum occupies eastern North America. Sassafras tzumu grows in central and eastern China, primarily in provinces like Zhejiang, Anhui, and Jiangxi. Sassafras randaiense is restricted to Taiwan. All three share the distinctive mitten-shaped leaves and aromatic bark that make the genus recognizable.

This east-Asia-to-eastern-North-America split is not unique to sassafras. Dozens of plant genera follow the same pattern, a legacy of ancient forests that once stretched continuously across the Northern Hemisphere before tectonic movements and ice ages fragmented them. For sassafras, the split means the genus’s full ecological story cannot be told by looking only at the North American species.

The Chinese species, S. tzumu, gives a window into how habitat shapes sassafras distribution under different conditions. A study of S. tzumu communities in Zhejiang province found that elevation and slope aspect were the major environmental variables determining where the species occurred.⁷ In China, the species is considered vulnerable and receives legal protection, a contrast with North America, where S. albidum is abundant and not threatened at the species level. The Chinese and Taiwanese species also face seed dormancy challenges that limit natural regeneration; breaking dormancy in S. tzumu seeds requires months of cold treatment combined with plant hormones.⁸

Laurel Wilt Disease and the Threat to Sassafras

The single largest active threat to sassafras across its range is laurel wilt disease, caused by a fungus introduced to the United States via the redbay ambrosia beetle, a tiny wood-boring beetle that arrived in shipping material from Asia. The fungus clogs the tree’s water-conducting tissue, and once symptoms appear, death usually follows within weeks. Laurel wilt first devastated redbay trees (Persea borbonia) along the southeastern coast starting around 2002, but it quickly jumped to sassafras and other members of the laurel family.⁹

The disease has been devastating in areas where it has arrived. Long-term monitoring plots in southeastern Georgia documented mortality of nearly 80% of sassafras trees in infected stands, with larger trees dying at higher rates.¹⁰ There is a faint silver lining: over a quarter of the killed sassafras trees produced epicormic shoots (emergency sprouts from the trunk) that survived for several years after infection, and smaller trees appeared to have some tolerance.¹⁰ Whether those survivors can sustain the population long-term remains an open question.

Geographically, the disease has so far hit sassafras much less than redbay in absolute terms. As of 2021, laurel wilt had invaded about 68% of counties containing redbay but only about 13% of counties with sassafras, affecting roughly 6% of total sassafras biomass.¹¹ That sounds reassuring until you consider that sassafras’s range extends far north and west of the current disease front. The disease can spread through sassafras even in areas where redbay is absent, which means it has a potential corridor deep into the interior of the eastern United States.¹⁰ Researchers have flagged this as a serious concern, not only for sassafras itself but because the beetle could use sassafras as a bridge to reach other laurel-family species farther west and south into Central and South America.

How Climate Change May Reshape the Range

Sassafras’s range has always shifted over geologic time, tracking the retreat and advance of glaciers. Today the question is whether it can keep pace with human-driven climate change. Modeling suggests the answer is mixed, and in some areas, probably not.

A 2024 study modeling forest composition through the end of this century projected that sassafras would be eliminated from four states, Mississippi, New Hampshire, Oklahoma, and Texas, under all climate scenarios tested.¹² Those states represent the tree’s range margins: the hot, dry southwestern edge (Texas and Oklahoma) and the cold northern fringe (New Hampshire). The core of the range, the central Appalachians and the Ohio Valley, is projected to remain suitable for much longer, though the composition of the forests sassafras grows in will shift as other species respond to the same pressures.

The losses at the range margins matter because they are not easily offset by gains elsewhere. Trees cannot migrate the way animals do. Sassafras relies on bird-dispersed seeds and clonal spread, both of which move populations slowly. Even if conditions become suitable farther north in coming decades, the tree’s colonization speed may not keep up with the rate at which southern habitats become inhospitable. The fact that sassafras is already extending into northern Illinois, as noted in USDA records, hints that northward movement is happening, but whether that creep can compensate for losses at the southern and western edges is uncertain.

Growing Sassafras Outside Its Native Range

Sassafras is occasionally planted as an ornamental outside its native range, prized for its brilliant fall color and distinctive leaf shapes. It can grow in USDA hardiness zones 4 through 9, which covers a wide swath of the continental United States. The tree is relatively easy to establish from nursery stock, and it adapts to a variety of garden soils as long as drainage is decent.

That said, transplanting sassafras is notoriously difficult. The tree develops a deep taproot early in life, and disturbing it often kills the plant. Starting from seed or buying small container-grown seedlings gives much better results than trying to move a larger tree. Once established, sassafras needs little maintenance, though gardeners in heavy clay should be prepared for the possibility that the tree will never truly thrive.

The clonal spreading habit that makes sassafras so persistent in the wild can be either a feature or a nuisance in a garden setting. A single tree will eventually send up root sprouts around itself, and in a small yard, this can become hard to manage. If you want a single specimen tree, you will need to mow or cut the sprouts regularly. If you have space for a naturalistic grove, letting the sprouts go can produce a beautiful multi-stemmed thicket that attracts birds with its fall fruit.

Sassafras and Soil Ecology

Sassafras litter chemistry has measurable effects on the microbial communities in the soil beneath it. When sassafras leaf litter breaks down alongside litter from other tree species, it shifts the balance of bacterial and fungal groups in the soil. Research on mixed-litter decomposition found that combining sassafras litter with larch litter increased the abundance of a fungal group responsible for breaking down organic matter while decreasing certain bacterial groups. Litter pH and total carbon concentration were the main factors driving these shifts in microbial community structure.¹³

This is consistent with the allelopathic story described earlier. Sassafras is not a passive member of its ecosystem. Its chemical outputs, both above and below ground, actively shape what grows around it and how the soil ecosystem functions. For land managers working with sassafras-dominated sites, this has practical implications: the soil chemistry under a long-established sassafras stand may not immediately support the same species composition you would expect elsewhere, and restoration projects that remove sassafras may see unpredictable shifts in plant community composition as the allelopathic and litter-chemistry effects fade.