Sassafras albidum

Description

Sassafras albidum is a medium-sized deciduous tree and the northernmost member of the largely tropical laurel family (Lauraceae). It typically reaches 15-20 metres in height with a rounded, irregular crown up to 12 metres wide. The bark on mature trunks is thick, deeply furrowed, and dark reddish-brown — mahogany-like and distinctive. Young shoots are bright yellow-green and mucilaginous, maturing to reddish-brown. The roots are thick, fleshy, and aromatic, and they freely produce suckers that can form extensive clonal thickets around a parent tree.

The leaves are the tree's most celebrated feature, occurring in three distinct shapes on the same branch: unlobed and elliptical, two-lobed (mitten-shaped), and three-lobed. All are 10-15 cm long, bright green, and highly aromatic when crushed. In autumn they turn spectacular shades of yellow, orange, and red — among the finest fall displays of any native tree. The specific epithet albidum refers to the pale or whitish undersides of young leaves.

S. albidum is dioecious: male and female flowers occur on separate trees. Both sexes produce small yellow-green flowers in loose, drooping racemes in early spring before the leaves emerge. On female trees, pollinated flowers develop into dark blue-black drupes about 1 cm long, each borne on a thickened, bright scarlet pedicel — a striking and ornamental fruit display in late summer.

Growing Conditions

Prefers rich, moist, well-drained, acidic sandy loams with a pH of 6-7. Naturally occurs in open woodlands, forest edges, fencerows, and disturbed sites throughout the eastern deciduous forest. While it prefers fertile soil and full sun for optimal growth, it tolerates a wide range of conditions including part shade, occasional wet feet, and nutrient-poor soils. Tolerates alkaline conditions better than most acid-loving species.

Hardy from USDA Zone 4 through Zone 9. In Ontario, it is restricted to the Carolinian zone, where it reaches the northern limit of its continental range. Seedlings tolerate shade but saplings and mature trees require full sun for good growth. The tree is allelopathic, producing compounds that suppress competing vegetation within its root zone. An excellent colonizer of disturbed sites and canopy gaps, where it can establish rapidly from root suckers.

Phenology

Flowers appear in early spring (March through May) before the leaves emerge, carried in loose, drooping racemes. The small yellow-green blooms are insect-pollinated and only female trees set fruit. The dark blue drupes ripen on their scarlet pedicels in late summer (August-September) and are quickly taken by birds.

Leaf-out follows flowering. The distinctive three-shaped foliage provides a long season of interest, turning brilliant yellow to orange-red in autumn. The tree is fully deciduous, dropping leaves by late October. Root suckers are produced most vigorously during the growing season, and seedlings establish in spring. The aromatic bark and roots retain their spicy fragrance year-round.

Ecology

Sassafras albidum is a keystone larval host, supporting caterpillars of 37 species of Lepidoptera. Among the most notable are the Spicebush Swallowtail (Papilio troilus), Eastern Tiger Swallowtail (Papilio glaucus), Palamedes Swallowtail (Papilio palamedes), and Pale Swallowtail (Papilio eurymedon). Giant silk moths including the Cecropia (Hyalophora cecropia), Promethea (Callosamia promethea), Polyphemus (Antheraea polyphemus), Imperial (Eacles imperialis), and Io (Automeris io) also use sassafras as a larval host.

The fruits are an important late-summer food source for birds, including thrushes, catbirds, flickers, and pileated woodpeckers, which disperse the seeds. Small mammals also consume fallen fruits. The aromatic foliage and bark contain volatile terpenoids including safrole, which deter most herbivores — deer browsing on sassafras is uncommon. However, these same aromatic compounds attract the invasive redbay ambrosia beetle (Xyleborus glabratus), vector of laurel wilt disease, an emerging threat to Lauraceae in eastern North America that may reach Ontario as the beetle's cold tolerance expands.

Propagation

Seeds require 30-60 days of cold-moist stratification at 1-5 °C. Collect fruits when they are plump and dark blue (only a small percentage of trees bear fruit — ensure collection from female specimens). Clean seeds of the fleshy pulp and stratify immediately or store in sealed, refrigerated containers. Sow stratified seed in spring in a nursery bed; germination is typically reliable.

Root cuttings taken in early spring before leaf-out root readily. Root suckers can be dug and transplanted from established colonies in spring or fall. Growth from root suckers is remarkably fast — shoots can reach 1.2 metres in the first year and 4.5 metres within four years. Seed-grown trees grow more slowly and may take 5-10 years to reach flowering size. In cultivation, root suckering can be controlled by mowing or by planting in a location where spreading is desirable.