Gardeners in Wisconsin should be aware that additional plants have recently been added to the Wisconsin Invasive Prohibited and Restricted Species lists.
With certain exemptions*, ‘Restricted’ and ‘Prohibited’ plants may not be transferred (bought, sold, given away), transported, or introduced (imported or planted) in Wisconsin. In addition, ‘Prohibited’ plants must be controlled.
Prohibited Species: Prohibited species are not yet widely established in the state and pose great economic or environmental threat. Prohibited species may not be transported, transferred, possessed or introduced without a permit. Control of existing populations will be required.
Some notable Prohibited Species added to the list include common barberry, Asian loeseneri bittersweet, Japanese/Chinese wisteria, Southern cattail, Graceful cattail, and Seaside goldenrod. Species previously listed as prohibited included Japanese honeysuckle and Japanese hops.
Restricted Species: Restricted species pose great economic or environmental threat, but are already widely established in the state. Restricted species may be possessed, but may not be transported, transferred or introduced without a permit. Control of existing populations will be encouraged.
Some notable Restricted Species which may already be found in many Wisconsin yards include Amur maple (all cultivars exempt), Black locust, Japanese barberry (some cultivars, varieties, and hybrids are exempt), Siberian pea shrub (Cultivars Lorbergii, Pendula, and Walkerii are exempt), Burning bush (straight species and cultivar Nordine are restricted-all other cultivars are exempt), Bishops goutweed, Wormwood, Yellow flag iris, Golden yellow loosestrife, and Moneywort (Cultivars Aurea and yellow and gold leaf forms are exempt), and Woodland forget-me-knot. Species previously listed as restricted included Common buckthorn, Glossy buckthorn, Russian olive, Morrow’s honeysuckle, Tartarian honeysuckle, Bell’s honeysuckle, Multiflora rose, Oriental bittersweet, Garlic mustard, Creeping bellflower, Plumeless thistle, Musk thistle, Canada thistle, Cypress spurge, Leafy spurge, Dame’s Rocket, Purple loosestrife, Narrow-leafed cattail, and Hybrid cattail.
Additional Regulated Invasive Plants in Wisconsin *: http://dnr.wi.gov/topic/Invasives/documents/NR40_handout_Rd2_Final_vcs5.pdf
Regulated Terrestrial Invasive Plants in Wisconsin: http://dnr.wi.gov/files/pdf/pubs/fr/FR0464.pdf
* The plants listed here were regulated by NR40, Wisconsin’s Invasive species rule as of May 1, 2015. ‘Restricted’ plants on this list that were in the state as of May 1, 2015 may continue to be sold, transferred, transported and planted until May 1, 2018 for herbaceous plants and vines, and until May 1, 2020 for trees and shrubs.
An additional list of non-regulated plants that have been designated as Caution Species (species that may have show evidence of invasiveness in similar environments in other states and could potentially spread in Wisconsin but more information is needed about their ability to survive here and where they are currently established) might be considered carefully before adding them to the garden. These include some species commonly planted in our area such as Norway maple, Globe thistle, Baby’s breath, English ivy, Orange ditch lily, Purple moor grass, Callery pear, Siberian squill, and Periwinkle (Vinca minor).
posted by Sue