October, 2009.  We are enjoying a spectacular autumn, far better than 2008.  A Tuliptree (Liriodendron tulipifera) that last year was just a sad browny-beige, is currently realizing its full potential for vibrant golden yellow.  Could it be because of the light frosts we had 10 days ago?  Dogwoods are purple, red maples are red, and the neighbor's front yard Freeman Maples (Acer x freemanii) are a spectacular orange-red. ( The Freeman Maple is a hybrid between Red Maple and Silver Maple, and it has the Silver Maple's quick, spectacular growth, plus the Red Maple's vibrant fall color.)  As for shrubs, my native Chokeberry (Aronia arbutifolia) is just now turning a soft red-purple. This is a shrub that could be planted in place of the exotic invasive Burning Bush.  It colors later than BB, but lasts longer, and its berries feed the birds. Looking for landscape design education in some form?  I have taught Tree Identification for the Town of Lexington's Tree Committee, and would consider taking on similar projects. ...read more

Invasive Species – Impact on Public Lands Most communities northwest of Boston have public lands are filled with aggressive invaders. These are minimally managed areas, such as the woods along a railroad or Bikeway, the edges of the conservation lands, and even property lines between homeowners, are host to an overabundance of Norway Maple, Buckthorn, Multiflora Rose, Oriental Bittersweet, Japanese Knotweed, Asian Honeysuckles, Barberry, Burning Bush, Garlic Mustard, Purple Loosestrife, Black Swallowwort and other exotics. The Commonwealth of Massachusetts has passed legislation that bans the import, sale, or propagation of 140 species of exotic plants. You can find the whole list at  http://www.mass.gov/agr/farmproducts/proposed_prohibited_plant_list_v12-12-05.htm. Many of the plants are weeds that one would not deliberately plant anyway, but there are also many commonly used landscape plants that are no longer permitted as of January 1, 2009.   Please note and AVOID planting any of these trees or shrubs: Norway Maple, including the dark-leafed varieties such as ‘Crimson King', Sycamore-leafed Maple,Japanese Barberry, Porcelain Berry, Autumn Olive,Burning Bush,Border Privet, any of the Asian Honeysuckles (Japanese, Amur, Morrow's, Tatarian, or Bell's), Amur Corktree, Black Locust, or Multiflora Rose.  Pull them out if you have them, and can reasonably do so. A native plant species in North America is usually defined as one that was present before the arrival of European colonists. A non-native, exotic species may become invasive depending on where it is, and the number of specimens present in an area. A particular plant species might be invasive in one state and not in another. When multiple plants appear at one site, crowding out other growth, it would be considered invasive. When a non-native tree such as the Norway Maple (Acer platanoides) is planted on a private property, typically the homeowners mow around it, pull up its seedlings, and take care of the property. In that spot, it is not a problem. However, the great quantities of seed it produces blow around the neighborhood and take root in minimally managed areas. This maple's rapid growth rate, shallow water-gulping root system, very dense canopy and longer growing season soon shade out anything else growing nearby, reducing the numbers of indigenous plants available to supply food to native animal life. The dangers of unchecked non-native plant invaders, besides the possibility of extinction of plant or animal native species, also include the diminishment of ecosystem functions of importance to humans, such as water filtration, wood production, and recreation, as well as the mounting economic cost of control efforts. As citizens of the Commonwealth, we can be responsible by learning more about invasive species, by eliminating them from our own land so they don't spread to public property, and by replanting native and non-invasive species.  ...read more

           Trees are an important but sometimes overlooked monetary asset to any municipality. They are an environmental boon, performing functions of scrubbing pollutants out of the air, breaking the force of rainwater, taking up excess moisture, reducing street temperatures by as much as 20 degrees in the summer, and reducing the need for air conditioning. They make the streets pleasant to walk on, and sustain birds and other wildlife.               There is monetary value to all these functions. Studies by the Center for Urban Forest Research (of the U.S. Forest Service) indicate that “each large, mature tree in an urban community provides environmental benefits valued between U.S. $100 and $200 per year.” Other studies find that large trees give a higher net benefit than small or medium trees, even though they are more expensive to maintain, and that people will spend more time shopping and spend more money in a well-treed commercial environment.               Homeowners!! A building lot with trees on it has been estimated to be worth 15% to 17% more than one that has none, and a mature beech tree in a front yard can add tens of thousands of dollars to the value of a property.               Nevertheless, it is sometimes difficult to put a hard number on the value of street trees. There are various formulae for determining the value of an individual tree. The variables have to do with age, species, condition, size, and whether it is in a prominent site. However, knowing these values can also help the town recoup insurance monies in case of damage by persons, vehicles, or in case of natural disasters (windstorms, flooding, or ice storms).               What is certain is that we often don’t get long-term value out of the money we currently put into tree planting. From minimally prepared planting sites, the results of compacted soils, impervious surfaces, heat irradiation, pollution, and other stresses, give to urban trees an average expected service life of only 10 to 25 years. Another factor in poor performance is excessive road salt application.               In the fact of declining municipal budgets for tree planting, managers need tools to prolong tree lifespan, and reduce maintenance costs of treating sick trees and removing failing ones.               What are these tools?  n     Planting a wide variety of species to avoid losses due to insect and disease outbreaks among monocultures.  n     Off-berm planting; that is, planting street trees on the other side of the sidewalk, where growing conditions are better and private property owners will give them better care. n     Preparing each planting site more carefully, using some or all of the following:            -- first-season regular watering using buried watering tubes            -- larger tree pits            -- structural soil to support new sidewalks            -- permeable materials for sidewalks surrounding tree pits (bricks, not concrete, etc.)   (The first of a planned series of occasional blogs by Karen Longeteig, Landscape Designer and community tree committee member)   ...read more