Go Green with Green Roofs

There are both small steps and big steps you can take to go green and show your commitment to the environment.  A small green step would be using canvas shopping bags, while a big green step would be purchasing a super fuel-efficient hybrid or electric car.  As gas prices climb higher and higher, buying that fuel-efficient car seems more and more like a big green step people are willing to take.  But if you already have a hybrid car, there are other big steps you can take to continue to “green-ify” your life.  Installing a green roof is one of these.  Green roofs offer a fantastic way to reduce your carbon footprint, and offer a space for you to experience your own little patch of Eden. 

Photo: Green roofs can provide both environmental benefits and beauty. Chelsea, New York City 

A green roof is a highly engineered extension of the roofing system that uses plant life to meet functional and aesthetic needs.  Green roofs are quite diverse and may consist of a thin mat of low-lying vegetation, or a highly diverse planting of perennials, shrubs, and even trees.  How your green roof is designed will depend on how much you are willing to monetarily invest initially, how much soil and weight your existing roof can support, and how much use and access you will need to the finished green roof.  The best green roof plants are drought- and cold-tolerant, and have low nutrient requirements and a shallow root system.  Plants that are evergreen are also favored because they are able to insulate a home year-round.  Many different types of sedums have performed remarkably well as green roof plants.    

Photo: Sedums like Goldmoss Stonecrop (Sedum acre) make excellent green roof plants

Like traditional gardens, green roofs offer both environmental benefits and beauty.  But green roofs will also save you money.  By insulating buildings, green roofs provide improved energy efficiency.  It is estimated that green roofs provide an 87% reduction in heat gain in the summer, and a 37% reduction in heat loss in the winter.*  Also, the lifespan of a green roof is 2-3 times that of a traditional roof, leading to lower roof maintenance and replacement costs.  Green roofs also help reduce stormwater runoff by absorbing, retaining, and cleaning rainwater.  Investments in green roofs and other green infrastructure, are extremely important for municipalities including New York City that have reached the functional limits of existing sewers and other grey infrastructure.

Although virtually unknown in the United States until a few years ago, green roofs have actually been in use for hundreds of years.  In Scandinavia, sod or turf roofs have been used for centuries in traditional home construction.    The first “modern” green roof dates back to 1914 in Zurich, Germany.  While green roofs are now fairly common in Europe, there is much potential for expansion in the U.S.  Many cities have recognized the environmental benefits provided by green roofs, and are now offering incentives to homeowners and businesses for green roof installation.  If you live in New York City, you’re in luck.  A tax abatement equal to $4.50 per square foot of green roof space up to $100,000 is now being offered.  (For more info, check out http://www.nyc.gov/html/dob/html/forms/forms_tax_abatement.shtml)  Make sure to obtain any required permits that comply with zoning and building codes before beginning green roof construction.

Photo: Queens Botanical Garden features a green roof and a stormwater catchment system that recycles water back into the gardens. Flushing, Queens

If you are looking for a little green roof inspiration, a great place to check out is the Queens Botanical Garden in Flushing (www.queensbotanical.org).   Their new Visitor & Administration Building features a walkable, gently-sloping green roof.  The 3,000 square-foot roof is planted primarily with drought-tolerant native perennials.  Stormwater that is not utilized by the green roof is recycled back into the gardens through a stormwater catchment pool. 

Whether you decide to install a green roof on your home or not, make sure all your steps are green ones!

*Source: A Temperature and Seasonal Energy Analysis of Green, White, and Black Roofs. Gaffin, S.R., Rosenzweig, C, et.al. Center for Climate System Research, Columbia University/Con Edison, April 2010.

Breakin' the Law - Illegal Plants

When I talk about illegal plants on Long Island, I’m NOT talking about a certain one used for “medicinal” purposes.  What I am talking about are invasive plants.  Two years ago, it actually became illegal to sell, transport, distribute, and propagate dozens of invasive plants in both Nassau and Suffolk Counties.   Invasive plants are not just harmless little weeds and dandelions - invasive plants are the thugs of the plant world.  They can cause considerable damage to natural habitats by invading ecosystems which they are not native to, and displacing the native flora.  The population of native plants is then reduced or even wiped out in some cases.  This in turn affects wildlife and other species which may be dependent upon the local flora for food or habitat.  The introduction and spread of invasive species is the second leading cause of global biodiversity loss. (Habitat loss is the number one leading cause.)  About 42% of species listed on the U.S. Threatened or Endangered Species Lists are at risk primarily due to competition or predation from invasive species.* 

Photo:  The invasive vine, Sweetautumn Clematis (Clematis terniflora), engulfing vegetation along the Peconic River in Riverhead

You may be asking, so how do these tough non-native plants overtake our “wimpy” native plants?  The answer can be explained by evolution.  Because a non-native plant did not evolve with the local species, it may have few or no herbivores or pests that like to eat it in its new location.  It also may have developed superior ways to acquire essential resources such as water or sunlight compared to the local species, which makes it a better competitor.  Like real thugs, these invasive plants also bring bigger and badder gats to the gunfight.  Certain characteristics allow a plant to adapt quickly to a new environment, thrive, and spread.  Most invasive plants possess one or more of these characteristics which include, abundant reproduction; rapid growth rate; short generation time; ability to occupy many different habitats; ability to adapt to changing environments; effective seed dispersal; long-lived seeds; and being poisonous or allergenic to other organisms.

Photo:  The invasive shrub, Autumn-Olive (Elaeagnus umbellata), colonizing an old field in Calverton

So what might look like some nice greenery, might actually be the battlegrounds of ecological warfare, where rampant, Oriental Bittersweet vines (Celastrus orbiculatus) are engulfing full-grown trees, Phragmites reeds (Phragmites australis ssp. australis) are choking out waterways, and Mugwort (Artemesia vulgaris) is invading our gardens.  The cost of controlling invasive plants is mind-boggling!  In 2005, the annual cost to the US economy for invasive herbaceous weeds (not including trees and shrubs) was estimated to be $27 billion in crop systems, $6 billion in pastures and rangeland, $1 billion in golf courses, and $500 million in residential yards and gardens!*

 Many people are working hard to control invasive plants, including park and wildlife refuge managers, botanists, environmental engineers, landscapers, and now even Long Island legislators.  But even the world’s top biologists and ecologists cannot predict what the outcome will be of this ecological war – will most species of native plants perish in the wake of invasive plants?  Will native and invasive plants establish an equilibrium and co-exist?  Will invasive plants die-out in a couple decades or centuries as the native flora and fauna evolve with them? 

Although the answers to these questions remain unknown, “thinking globally and acting locally” rings true in this situation.  Being concerned about global biodiversity can spur us to action in our own backyards and gardens.  You can start by learning how to correctly identify invasive plants and remove them from your yard.  Definitely make sure to not buy illegal invasive plants that are now banned on Long Island.  You may want to consider growing or planting species native to Long Island or the Northeast.  Native plants are a wonderful way to preserve local biodiversity and attract birds and wildlife to your backyard.  However, be sure to remember that there are also many non-native, NON-invasive ornamental plants that also make great selections, especially if you are planting in a tough location. 

For the list of illegal plants on Long Island, visit http://ccesuffolk.org/nursery-and-landscape-current-projects/.  This page will also give you suggestions for alternatives to long-standing ornamental plants that have been found to be invasive, like Norway Maple (Acer platanoides) and Japanese Barberry (Berberis thunbergii).  By each of us doing our part, maybe we’ll eventually be able to win the weeds war!

Photo: The invasive ornamental shrub, Japanese Barberry (Berberis thunbergii), can produce up to 9,900 seeds per plant, depending on cultivar

*Source:  Pimentel, D., R. Zuniga, and D. Morrison. 2005. Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological Economics 52: 273 – 288.

Trees for All Seasons

Everyone can appreciate a lovely, ornamental tree covered in springtime blossoms.  In April, the pears, plums, cherries, and magnolias don a canopy of delicate white and pink flowers, ushering in the new spring.  These charming little trees look absolutely stunning at this time of year.  But only after a few short days, the blossoms begin to wither, turn a mushy brown, and give way to new leaves.  With their showy flowers gone, these trees quickly fade into the nondescript, surrounding landscape.

 If you’re a person like me, who wants more from your garden than two weeks of flowers followed by BLAH, let me recommend two rather unusual ornamental trees – Paperbark Maple (Acer griseum) and Japanese Stewartia (Stewartia pseudocamellia).  These two trees are what you would call four-season plants, which are hard to come by.  Both Paperbark Maple and Japanese Stewartia add remarkable beauty to the landscape in every season, even winter. 

Paperbark Maple is a small, ornamental maple tree that grows up to 20-30 feet tall.  Originally from China, it grows slowly and is hardy in zone 5 to 7, sometimes 8.  Like its name suggests, Paperbark Maple has unique bark that exfoliates like the bark of a Paper Birch, in long, curling strips.  The bark begins exfoliating at a young age.  But the color of the bark is even more remarkable.  No other tree that I know of has such vibrant, deep, rust-colored bark.  Paperbark Maple is especially head-turning in winter when the orange-spice bark prominently stands out against white snow. 

Photo: Paperbark Maple (Acer griseum) at Planting Fields Arboretum, Oyster Bay

Paperbark Maple is adaptable to many different soil types and soil pH, although it performs best in well-drained, moist soil.  Paperbark Maple can be grown in partial shade or full sun.  This maple makes an excellent specimen tree and is a beautiful and stately addition to any home landscape.

Japanese Stewartia is also a small, ornamental tree that grows up to 20-40 feet tall.  If you absolutely must have a tree that flowers, Japanese Stewartia is a great choice.   

Photo: Summer flowers of Japanese Stewartia (Stewartia pseudocamellia)

Long after all the other trees have finished flowering, the 2-3 inch wide creamy white flowers of Japanese Stewartia open in the middle of the summer in July.  A couple months later, beautiful fall foliage displays scarlet, yellow, and wine-colored hues.  In the winter, plated exfoliating bark is its main attribute.  Hushed gray, brown, and pale orange bring interest to the winter landscape.  Japanese Stewartia is hardy in zone 5, sometimes 4, to 7.  This spectacular tree is best grown in moist, fertile, acidic soils in full sun. 

Photo: Exfoliating bark of Japanese Stewartia (Stewartia pseudocamellia) at Bayard Cutting Arboretum, Great River

Not surprisingly, Paperbark Maple and Japanese Stewartia are both Long Island Gold Medal Plant winners.  You may have to visit a few more nurseries to find these two trees, and you probably will have to pay more for them than the run-of-the-mill flowering pears, plums, and cherries, but they will certainly be worth the extra effort, especially in winter. 

Breaking the Ice

Although the shortest month of the year, February always seems like the longest to me.  The holidays are over and we’ve already endured months of cold.  After being pummeled with snow storm after snow storm, after ice storm, this year’s winter seems like it will never end.  Back-breaking snow shoveling, LIRR cancellations and delays, and sky-high heating bills have become the everyday drudgery of our lives.  Navigating around sudden potholes, snow-covered sidewalks, and black ice have made getting anywhere not only difficult, but also dangerous.  I see this hopeless frustration in the drawn faces of strangers on the street, in the disheartened facebook posts of friends, in the anxiety with which coworkers discuss the latest weather forecasts…  Seriously, we all seem to be sighing, will this winter ever end?!

Today, February 6^th, we finally seem to be getting a glimpse of the spring that will eventually come.  Although it’s only a high of 42°F, dozens of joggers are outside, gleefully smiling that they don’t have to run with a parka on.  The sun feels warm and the air smells fresh.  The hope and renewal of spring seems to have peeked into our collective unconscious.  Life doesn’t seem so bad as the ice and snow melt away.

After this winter, not only do our spirits need to be restored, but also our landscapes.  In particular, the recent ice storm has caused considerable damage to Long Island’s trees.  Ice accumulations can increase the branch weight of trees 10 – 100 times.  Branch breakage occurs when the weight of the ice exceeds the wood’s resistance to failure, or when the added weight further stresses an already weakened area.  On average, US ice storms cost $226 million annually in monetary losses to forests, trees, utility lines, property, agriculture, and commerce! (See Trees and Ice Storms by Hauer, Dawson, and Werner, 2006). 

Photo: Eastern Arborvitae (Thuja occidentalis) covered in ice, Commack

The first step in restoring trees after an ice storm, is to remove all trees deemed too hazardous to leave standing.  This can be determined by an ISA Certified Arborist.  For example, trees that have split in two, or that have been uprooted will likely need to be removed immediately.  Trees that have had over 50% of their branches broken will also likely need to be removed.  Evaluating which trees should be removed needs to be done on a case by case basis.  One tree species may eventually “recover” from damages, while the same damages may lead to decay and structural defects in another species.  Older trees will be less likely to recover from storm damages than younger trees.

Trees that have been damaged but do not need to be removed will need restorative pruning.  This involves properly pruning broken branches to the branch collar.  Promoting the development of a balanced crown should be a goal of restorative pruning.  Loose bark can be cut back to where it is solidly attached to the tree.  Tree mechanical support systems including cables and braces, may need to be considered in some situations.  Following corrective pruning, trees should be monitored regularly to ensure that decay has not spread and that a hazardous situation has not developed.

Photo: Although covered in ice, flower buds of Japanese Andromeda (Pieris japonica) give us hope of spring

Just as we need to be actively restored after a rough winter, so too do our trees and shrubs.  Instead of impatiently waiting for February to be over and done with, let’s use this month to prepare ourselves and our landscapes for spring.  Let’s recondition ourselves with positive thinking and let’s restore our damaged trees with corrective pruning.  Whatever the groundhog says, spring is coming!