Invasive and non-native plant species are a major concern in the landscape. Many believe non-native, aggressive species out compete native species reducing biodiversity in our landscapes. Some states, including Massachusetts, have started to ban the growth or importation of some of these species in nursery yards. A very familiar non-native aggressive plant species is the Norway maple tree. There is so much to like/dislike about the tree- its beautiful yellow fall color, its ability to push leaves out very early in the spring and keep them long into the fall, its fast growing dense habit, its efficient and effective seed dispersal method, its shallow root system making planting underneath its canopy next to impossible. These are some of the very reasons it was planted in such large quantities as street streets, in parks and home gardens across the northeast. Some enthusiastic native-only proponents are eager to eliminate this tree on sight- no matter the situation. Although I agree that native plants ought to be given a priority in our landscapes, managed and wild, I also understand the value of leafy greens especially in our urban environments. Cutting down a mature Norway maple thriving in a confined urban environment would not be a priority in my view. Below is a partial list of the many resources available- take some time to learn more about invasive species.

Massachusetts Invasive Plants Advisory Group
http://www.massnrc.org/mipag/publications.htm#edlist

New England Wildflower Society- Controlling Invasive Plants at Home
http://www.newfs.org/protect/invasive-plants/removal

Massachusetts Department of Agricultural Resources
http://www.mass.gov/agr/farmproducts/Prohibited_Plant_Index2.htm with links to detailed plant information at the National Resource Conservation Service plant database including image gallery

United States Department of Agriculture, National Invasive Species Information Center
http://www.invasivespeciesinfo.gov/plants/main.shtml

Most agree that planting in the spring or fall is acceptable. It's true for perennials and bulbs, but not always the case with shrubs and trees. Fall planting is generally considered to begin in mid-August and extend through mid October depending upon the current climatic conditions, namely soil temperature.

Although not an exact science literature states that particular shrubs and trees struggle with fall digging and planting. Literature put out by the American Association of Nurserymen (AAN), University of Massachusetts Extension (UMass Extension), Horticulture Magazine and even some nurseries list problematic species in various ways. The AAN lists many favorites like Acer rubrum/Red Maple, all Betula/Birch, Platanus acerifolia/London Planetree, all Pyrus/Pears, all Quercus/Oaks, all Zelkova/Zelkova among a handful of others. A 2001 printing of UMass Extension's “Hort Notes” categorizes the species in terms of “successfully established in the fall” and “difficult to establish in the fall”. A September 1987 article in Horticulture Magazine groups plants according to their “significant risk of loss”, “some degree of risk”, and “not at great risk”. Although the resources are more or less comprehensive, many of the same plants appear in each. It is prudent to take note and to plan accordingly.

In conclusion, if planting in the fall cannot be avoided care must be taken to monitor plants carefully and regularly, water thoroughly and frequently and allow sufficient time (6-8 weeks) for root systems to establish prior to the first frost.  Then cross your fingers and hope for good weather!