Those sweetbay magnolias growing in the northern portion of the tree's range are smaller than those growing in the warmer zones. The northern trees average between 10 and 30 feet high, sometimes resembling a shrub. In southern areas, this magnolia grows to as tall as 60 feet, with a trunk up to 18 inches wide. The limbs grow upright and spread out, with the tree taking on various shapes, including a pyramidal form.
Geography determines whether a sweet bay magnolia remains evergreen or loses its leaves. The northern trees shed their foliage, while Magnolia virginiana retains its leaves all year or most of the year in southern locations. The leaves grow to be as long as 5 inches, with a dark, shiny green upper surface, but a frosty-silvery underside.
Flowers bloom on Magnolia virginiana sporadically throughout the summer, beginning in June. The attractive flowers feature between nine and 12 white petals. The flowers appear almost waxy, opening as wide as 3 inches. Flowers are difficult to see due to the amount and size of the leaves. They generate fruits as long as 2 inches, containing reddish-orange seeds that burst out when the pods open in early fall.
The younger sweetbay magnolia branches have a green color and are quite smooth. The trunks of the older specimens have a thin, aromatic, smooth grayish bark. One characteristic that makes Magnolia virginiana useful for wet landscapes is its ability to thrive in damp soil. The tree requires wet, acidic soil; cold and windswept sites cause slow growth. Magnolia virginiana does best in full sun locations.