Common Name: White mulberry
Scientific name: Morus alba
Identification: White mulberry is a medium-to-large fast-growing deciduous tree up to 40’ tall with a rounded crown roughly equal in spread to its height. Some cultivated varieties have a weeping form. Young bark is orange-brown in color. The furrows in mature bark can also be orange brown. The leaves are simple, alternate, 2-7” long and up to 6” wide. They are rounded or heart-shaped at the base, and are toothed along the edges. Leaves can be undivided or lobed. Lobed leaves are often irregularly shaped while undivided leaves are ovate. Leaves are smooth, glossy and dark green on the top surface, and smooth dull green with hair only along the veins on the bottom surface. Yellow-green pendulous catkins emerge in early spring. Some white mulberry trees have flowers only belonging to one sex (dioecious), while others have both single-sex and perfect flowers. Only plants with female flowers can produce fruit. Fruits resemble blackberries, are ½ – 1” long, and usually ripen from white or pink to dark purple before falling in mid-summer.
Look-alikes: White mulberry is very similar in appearance to the native red mulberry (M. rubra), and the species are known to hybridize. Mature red mulberry trees are usually taller than white (up to 70’ tall in a natural setting). Red mulberry leaves are also somewhat larger, more flattened at the base, dull on the top surface (as opposed to shiny on white mulberry) and hairy on the entire bottom surface. Red mulberry requires higher quality habitat with rich, moist soil and partial shade, while white mulberry will grow in poor soils and prefers full sun. Purdue University has an excellent guide differentiating white mulberry from several similar species, including red mulberry, linked below. (Dirr and Warren 2019)
White mulberry is reported frequently throughout the southern most of the Great Lakes Basin but has not been reported in the northern regions of Minnesota or Wisconsin. It is most frequently reported near urban areas, including Cleveland, Chicago, Detroit and Toronto. On a continental scale, it occurs from coast to coast and has been verified in 48 states and three Canadian provinces. White mulberry is described by USDA as being hardy to -18oF (Zone 5a), which limits its distribution in the Great Lakes Region, though its range may shift northward in response to changes in climate.
Additional invasive species distribution data for specific Great Lakes jurisdictions is available via:
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- Midwest Invasive Species Information Network (Michigan)
- iMapInvasives (New York and Pennsylvania)
- EDDMapS Ontario
The seeds of white mulberry are spread locally by gravity and over longer distances by birds and wildlife, which eat the fruit.
White mulberry frequently occurs in sunny disturbed settings, including forest edges, old fields, riparian forests, and transport and utility rights of way. It can also invade prairies and grasslands and occurs in many types of secondary growth forest, but its intolerance of dense shade likely precludes it from older growth areas. It can also grow as a weed in agricultural crop fields.
White mulberry has been documented forming high-density single species stands in certain situations, but this behavior has not been noted in the Great Lakes region (Stone 2009). Although it occurs in many habitat types, its density is usually relatively low. However, white mulberry has the potential to threaten the native red mulberry through hybridization. Red mulberry is rare through much of its range and is a threatened species in Michigan. Hybrids of the two species disproportionately express white mulberry traits. White mulberry is generally much more abundant where the two species co-occur (Michigan Natural Features Inventory 2009).
The pollen of white mulberry is an irritant to people who suffer from tree pollen allergies. Pollen is produced in great abundance by male white mulberry flowers and is ejected at high speed, facilitating long-distance dispersal (Taylor et al. 2006).
White mulberry was introduced to the U.S. multiple times from China starting in the early 1600s with the goal of establishing domestic silk production (white mulberry foliage being the primary food of the silkworm). It has also been used as a landscape tree in difficult growing conditions due to its high level of adaptability (Missouri Botanic Garden). Today, female and polygamo-dioecious trees are not generally sold in ornamental horticulture due to the extreme messiness of their fruit. Male cultivars are still planted as landscape trees, though some municipalities in the Southern U.S. have banned their planting to reduce pollen levels (Fuller 2018).
Male cultivars of white mulberry do not produce fruit. However, they can pollinate wild growing female plants, contributing to invasive populations. They can also contribute to declines in native red mulberry populations through hybridization when planted close to forests.
Please see our Landscape Alternatives pages for more information about how the WIGL Collaborative selected alternatives.
| Alternatives for White Mulberry
Common name (Latin name) |
Large shade tree (>40ft tall at maturity) |
Tolerant of urban conditions |
Attracts birds and wildlife |
| Redbud (Cercis canadensis) | ~a | ~b | |
| Tulip poplar (Liriodendron tulipifera) | ✔ | ✔ | |
| Red mulberry (Morus rubra) | ✔ | ✔ | |
| American basswood (Tilia americana) | ✔ | ~a | ✔ |
| Ginkgo (Ginkgo biloba) Male cultivars (many) |
✔ | ✔ | |
| Little-leaf linden (Tilia cordata) ‘Greenspire,’ ‘Corzam’ CORINTHIAN® |
✔ | ✔ | ~b |
~ = trait is somewhat present but not as pronounced as in check-marked examples
a Redbud and basswood both have some tolerance to less-than-ideal soils, but redbud does not tolerate drought, and neither species tolerates exposure to road salt.
b Redbud and little-leaf linden both attract pollinator species, but neither attract a notably broad range of birds or mammals.
Green = native to part of the Great Lakes Basin
Blue = not native but not invasive
The WIGL Collaborative’s decision trees are designed to help site users, who are perhaps newly discovering that plants that are part of their home landscaping are invasive, prioritize which species should be removed first based on risk to the surrounding environment, economy, and occasionally, to human health. In a perfect world, everybody would remove all invasive plants from their landscaping right away, but in reality, removing mature woody plants involve a hefty investment of time and/or money. These diagrams can help people with multiple woody invasives in their landscaping prioritize to get the most benefit for their efforts.
To learn more about the methodology and information used to develop the decision trees and for helpful hints on how to answer the questions, please see the full report here (PDF).
The following is a brief overview of management techniques shown to be effective on white mulberry, though it should be noted that there is relatively little management information available compared to other woody invasive species. For more detailed information on how to use these techniques, visit our Management and Control page. For local assistance managing woody invasive species, please get in touch with a cooperative invasive species management group or a university extension program.
Timing and spread concerns: Whenever possible, plants with female flowers should be controlled before they begin producing fruit. If control is undertaken when fruit is present, it is best not to remove the plants from the site to avoid spreading seed.
Physical control: Small seedlings can be pulled from moist soil, and juvenile trees can possibly be pulled using equipment, though even young white mulberries have extensive root systems that may make pulling infeasible. Large trees can be cut down and the stump ground out with heavy equipment. Girdling (removing a strip of bark around the entire circumference of the main trunk) may be effective on larger trees. Top-killing methods such as mowing, felling, or grazing can be used to prevent fruiting and spread but will not provide long-term control.
Chemical control and combined approaches: In situations where white mulberry is not growing densely, targeted application methods prioritizing fruit-producing trees can prevent spread while minimizing off-target damage. Cut stump, basal bark, and stem injection application methods are effective (depending on trunk diameter) and can be conducted during most of the year, avoiding early spring.
With any treatment it will be necessary to monitor for and treat regrowth and new seedlings.
Resources on management of white mulberry:
- Dirr, MA and KS Warren. 2019. Morus alba In: The Tree Book: Superior Selections for Landscapes, Streetscapes, and Gardens. Portland, OR: Timber Press. 538.
- Fuller, CE. 2018. Blog post: Are mulberry trees causing your allergy problems? Texan Allergy and Sinus Center.
- Michigan Natural Features Inventory. 2009. Morus rubra (red mulberry). In: Native Species of Michigan Botanical Abstracts.
- Stone, KR. 2009. Morus alba. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. 9/5/19.
- Taylor, PE, Card, G, House, J, Dickenson, MH, and RC Flagan. 2006. High-speed pollen release in the white mulberry tree, Morus alba. Sexual Plant Reproduction. 19(1): 19-24.
Photo: Forest and Kim Starr via flickr.com
