Deciduous trees with leaves of variable size and shape, often on the same tree. Yellow fall color ranges from subdued to bright. Fruit resembles miniature black- berries and is eagerly gobbled by birds.
M. alba. WHITE MULBERRY, SILKWORM MULBERRY. Zones US, MS, LS, CS; USDA 6-9. Native to China, where its leaves are used as food for silkworms. Brought by European settlers to Jamestown, Virginia, where it escaped cultivation and quickly spread across the U.S., becoming a quite bothersome weed. Grows very fast, as much as 3 ft. per year. Takes rocky, alkaline soil; withstands just about any conditions, including heat, wind, salt spray, air pollution, and drought (but grows faster with regular water). Eventually reaches 3050 ft. tall and wide. Leaves are 6 in. long, often lobed; flowers are inconspicuous.
Male trees produce prodigious amounts of pollen, which can be a problem for allergy sufferers. In summer, female trees bear sweet, insipid white, pink, or purple fruit that stains pavement where it fallsand birds flock to the fruit, gorge themselves, and then proceed to sully any deck, car, driveway, or passerby unlucky enough to be below. Seedlings come up everywhere, and surface roots make it difficult to garden beneath the tree. 'Pendula' ('Teas Weeping'), is a low-growing, strongly weeping form, but a fruit producer. Fruitless (male) forms are better for home gardens, though they do produce pollen. Selections include 'Chaparral' (weeping), 'Fruitless', 'Kingan', and 'Stribling' (Mapleleaf').
M. bombycis 'Unryu' (M. australis 'Unryu'). CONTORTED MULBERRY. Zones US, MS, LS, CS; USDA 6-8. To 25 ft. tall and wide, with twisted, contorted branches useful in dried floral arrangements or for winter silhouette. Fast growth means that branches may be cut freely with no harm to the tree. Dark green, broadly oval, 6- to 7-in.-long leaves.
M. rubra. RED MULBERRY. Zones US, MS, LS; USDA 6-8. Native to eastern and central U.S. Well-behaved tree that resembles M. alba but is less weedy and produces less pollen and less fruit. Fruitred when immature, ripening to blackis somewhat larger than that of M. alba and has a better flavor. Does best in rich soil. 'Illinois Everbearing' is a hybrid between this species and M. alba; its fruit ripens throughout summer.