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January 5, 2026

January Weed of the Month: Rowan Mountain Ash

A 3-year phase out of rowan mountain ash started Jan. 1

By Monika Chandler, Minnesota Department of Agriculture - Rowan mountain ash, Sorbus aucuparia, is an attractive tree with a rounded canopy, white flowers, and bright orange to red fruit. This species is specially regulated on the Minnesota Noxious Weed List. On January 1, 2026, a 3-year phaseout of the tree began giving nurseries across the state time to adjust their stock. This tree will not be allowed for sale in Minnesota starting January 1, 2029, to prevent the planting of more rowan mountain ash trees. There is no requirement to control existing rowan mountain ash trees now or past the 2029 phaseout.

Planted and pruned trees can have a rounded canopy.

Download photo here.

Rowan mountain ash trees have long been considered mystical, providing protection against evil spirits and misfortune. The protection theme is common to Norse, Druid, Celtic, and Greek folklore. In the present day, rowan tree’s mysticism is in the Harry Potter series with a character named Rowan Khanna and with rowan wands which are attracted to the pure hearted and create strong defensive charms.

This popular tree was brought to North America from its native ranges in Europe and Asia. It was well established in New England colonial gardens in the 1700s. The extent to which it was planted as an ornamental, medicinal, or to ward off witchcraft is unknown. Archeologists have found evidence of rowan trees planted at the corners of New England homes, and crosses made from the wood, which were believed to offer protection from witchcraft.

Unfortunately, rowan mountain ash escaped cultivation and spread into forests. Birds and other wildlife eat the fruit and move seed to new areas. Mature rowan trees form the canopy while their seedlings cover the forest floor. It can overtake forests and suppress natural regeneration.

Folklore considered the 5-pointed star shape on each fruit to be a pentagram that warded off evil spirits.

Download photo here.

There are two similar native trees: showy mountain ash, S. decora, and American mountain ash, S. americana. Both species do well in north central and northeastern Minnesota. Showy mountain ash was named for its beauty. There are many online resources for Identifying Mountain Ash Species in Minnesota.

Although there is no requirement to control rowan mountain ash, there are best practices to limit the spread:

• Seedlings can be hand pulled to control small, young populations.
• For larger populations, identify and control mature fruiting individuals first.
• Cutting stumps and applying basal bark herbicide to trees, as well as foliar applications to the leaves of seedlings and saplings, may be effective. For herbicide recommendations, contact your local University of Minnesota Extension office.
• If you prefer to hire a contractor, see information on how to hire a tree care professional.

More information on rowan mountain ash is available on the MDA website. 

For more information on noxious weeds and invasive insects, listen and subscribe to Smarty Plants, a Minnesota Department of Agriculture podcast. 

MEDIA: Contact Brittany Raveill, MDA Communications, at brittany.raveill@state.mn.us or 651-201-6131 for more information on Weed of the Month