Invasive Plant Species Removal at Smith College

What is an invasive exotic plant? 
     an alien plant spreading naturally (without the direct assistance of people) in natural or seminatural habitats, to produce a significant change in terms of composition, structure or ecosystem processes
   –Cronk, Q.C. and J.C. and Fuller, Plant Invaders, Chapman & Hall, 1995

Why do botanic gardens have invasive plants?

For centuries botanic gardens have been collecting and displaying plants from across the globe. The plants were studied, classified, preserved, propagated, and further distributed to other gardens. Over the years exotics were often introduced into commercial trade and became part of the landscape far from their native regions. At first no one realized there could be any negative consequences to introducing so many species. When some of the introduced plants escaped cultivation, a few of them grew in large numbers and spread, displacing native flora and disrupting the balance of ecosystems.

Assessment & Removal of Invasive Plants 

Student interns at the Botanic Garden of Smith College analyzed the problem of invasive plants on the Smith campus, assessing how many plants in our collection needed to be removed because they are now known to be invasive. We removed smaller species on the list and contracted out the removal of larger specimens. Students also worked on a remediation and restoration project along the Mill River in collaboration with the New England Wildflower Society. The removal of all invasives is an ongoing process that will take several years. Replacement plants have been installed in most locations. 

Tree, Shrub, and Vine Removal in the fall of 2006

3 Acer plantanoides, Norway maples between Lamont and Unity House
1 Acer plantanoides, Norway maple at Hopkins (towards College Lane)
1 Acer plantanoides,Norway maple at Hubbard House
1 Ailanthus altissima, tree of heaven near Ziskind House
1 Phellodendron amurense, amur cork tree at Park House
1 Phellodendron amurense, amur cork tree at Parsons
3 Euonymus alatus, winged euonymus at Wright Hall
1 Euonymus alatus, winged euonymus at Nielson Library
3 Euonymus alatus, winged euonymus near Admissions
3 Euonymus alatus, winged euonymus near 10 Prospect Street
1 Euonymus alatus, winged euonymus at Northrup southwest corner
5 Berberis thunbergii, Japanese barberry at Ziskind southwest
2 Berberis thunbergii, Japanese barberry at Capen Garden
1 Berberis thunbergii, Japanese barberry at Unity House
1 Lonicera morrowii, Morrow’s honeysuckle at Northrup north
1 Lonicera japonica, Japanese honeysuckle at Allbright House
1 Celastrus orbiculatus, oriental bittersweet at the Campus School

See Also: 

Student Research Projects on Invasives 

Regional legislation has been enacted to deal with this issue. The state of Massachusetts has guidelines published on line at: Massachusetts Department of Agriculture

What local environmental groups and wildlife experts are doing:
Native Plant Trust - (formerly New England Wildflower)