Mulberry Morus nigra L.; Morus rubra L.; Morus alba L. Moraceae

Species description Cultivated mulberries are deciduous trees and shrubs, with alternate, broad, many-lobed leaves. Red mulberry (Morus rubra) is the largest of the species and usually grown for fruit. Red mulberry leaves are sometimes lobed with blunt teeth, rough on upper surface and finely hairy underneath. Black mulberry (M. nigra) trees have rough and often unlobed leaves, and tend to grow as a shrub. White mulberry (M. alba) has generally thin, light green leaves, glabrous on upper side and finely hairy underneath. The flowers of these species are dioecious or monoecious, cylindrical wind-pollinated catkins. The fruit is obovoid to cylindrical, resembling a blackberry, sweet to somewhat tart, and the color ranges from white to red to black, though fruit color does not necessarily correspond to the species names.

Natural and cultural history Red mulberry is native to eastern North America, from southern Canada to Florida and west to central Texas, and many native peoples used it as a food source. Black mulberry is native to western Asia, where it was cultivated for thousands of years, and later transported to Greece, Rome, and the rest of Europe. White mulberry is native to central and eastern China, where it is grown for its leaves to feed silkworms. White mulberry has escaped into wild areas in North America and can be invasive. Many varieties and hybrids have been developed for improved flavor, increased production, and higher fruit yields. In the Himalayas, dried mulberries have long been a winter staple; the berries are finely ground and mixed with almonds.

Planting considerations and propagation techniques Mulberry trees grow 20-30 feet in height and in canopy diameter. Some species may live up to 300 years. Depending on the species and variety, some are hardy to 0ºF. Mulberries prefer full sun but will tolerate partial (50%) shade; the trees make a good overstory tree, attracting birds, wildlife and pollinators. Mulberry fruits can be messy, so avoid planting trees near driveways and sidewalks/walkways. The trees are wind pollinated and self-fertile, but cross-pollination provides greater yields.

Mulberry can be propagated from hardwood, softwood and root cuttings. Rooting hormone increases rooting. The seeds need at least 13-16 weeks of stratification for germination. Seed-grown plants require longer growing time to produce fruit.

Water needs Mulberry trees have medium water requirements once established. Mulberry shrubs and trees prefer rich, moist habitats and should be given regular deep irrigation in the summer.

Care Birds can be a serious pest, indeed mulberries are often recommended as trees to distract birds from other fruit trees. Mulberry trees may be susceptible to popcorn disease, cankers, scale, and general dieback. Young trees require training to develop a sturdy branch framework. Beyond training, no special pruning techniques are required. Remove dead and over-crowded branches; mulberries heal poorly from large wounds, so avoid larger cuts.

Harvesting and processing

Harvest the fruit when they ripen in August and September. Fruits may be hand picked, or sheets can be laid down beneath the branches, and the tree given a good shake. Ripe fruits drop easily. Ripe mulberries are extremely perishable and will not keep more than a couple days even under refrigeration. The fruit is delicious, however and may be eaten fresh, dried, or cooked into pies, jams, and jellies.

References and resources California Rare Fruit Growers (CRFG). 1997. Mulberry. https://www.crfg.org/pubs/ff/mulberry.html Ladybird Johnson Wildflower Center. Native Plants Database (NPIN). 2015. Morus rubra. http://www.wildflower.org/plants/result.php?id_plant=MORU2 Orwa, C., A. Mutua, R. Kindt, R. Jamnadass, and S. Anthony. 2009. Morus nigra. In, Agroforestree Database: A tree reference and selection guide version 4.0. http://www.worldagroforestry.org/treedb/AFTPDFS/Morus_nigra.pdf Plants for a Future (PFAF). n.d. Morus alba - L. http://www.pfaf.org/user/Plant.aspx?LatinName=Morus+alba Plants for a Future (PFAF). n.d. Morus nigra - L. http://www.pfaf.org/user/Plant.aspx?LatinName=Morus+nigra Plants for a Future (PFAF). n.d. Morus rubra - L. http://www.pfaf.org/user/Plant.aspx?LatinName=Morus+rubra Reich, L. 2008. Morus spp. Mulberry. pp. 504-507. Eds. Janick, J. and R.E. Paull. The Encyclopedia of Fruit and Nuts. CABI Publishing, Cambridge, MA. Stone, K.R. 2009. Morus alba. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2016, June 16] Suttie, J.M. n.d. Morus alba L. Food and Agriculture Organzation of the United Nations. http://www.fao.org/ag/agp/agpc/doc/gbase/data/morusalba.htm U.S. Department of Agriculture (USDA), Natural Resource Conservation Service (NRCS), National Plant Data Center. 2003. Red mulberry: Morus rubra L. http://plants.usda.gov/plantguide/pdf/cs_moru2.pdf

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