Following a full day of soil science education and information exchange with consultant Eric “T” Fleisher, Swarthmore College’s Organic Lawn Care Initiative is one step closer to implementation. As I discussed in my last blog post, I am spending my summer internship helping the Grounds Department and Scott Arboretum transition the five-acre Mertz field into an organic lawn, and Monday, July 12 was a critical day in this process. T’s visit is the first pass toward a feasible and effective detailed program design.

We approached T after hearing about his work on Harvard University’s Soils Restoration Project, upon which our program is roughly based. T is the Director of Horticulture at the 37-acre Battery Park City Parks Conservancy (BPCPC) in lower Manhattan. Since 1989, he has been guiding the organization in the use of sustainable grounds management methods, based on the development of a balanced soil ecology, with an emphasis on composting, water conservation, and the use of non-toxic means of pest and disease control. BPCPC is the only public garden space in New York City to be maintained completely organically.

T presents his lecture “Managing the Environment: An Adaptive Challenge” in the Gillespie Classroom of the Wister Center. photo credit: C. Robertson

T began his Swarthmore visit with a presentation and question and answer session on his experience with organic horticultural practices. It was attended by 35 representatives of our staff, the college Sustainability Committee, the Pennsylvania Horticultural Society, local public gardens, Penn State research and extension centers, and local turf care companies. He explained to the audience that pioneering new techniques for managing environmental systems is an adaptive, rather than technical, challenge. Exploring new sustainable management practices requires philosophical and behavioral changes, moving beyond the established “quick-fix” answers that are effective in 85-90% of situations.

Applied to organic lawn care, an adaptive approach means understanding the turf as an environmental system before making any amendments. To attain this perspective, T spent the afternoon conducting a comprehensive site assessment. We gave him a tour of our compost facilities, showed him where we plan to install two solar-powered compost rotators, our compost tea brewing station, and explained what equipment and resources we own or have access to. Then, similar to what I performed last month, T used a spade to gather more soil samples. This set will be sent to a lab called Soil Foodweb, which specializes in biological content testing. Once the tests establish what microorganisms are already present in our soil and compost, T will help us further develop and modify our composting program (already 80% of the way there!), create the compost tea recipes that will best foster natural nutrient cycles in the soil, and adapt our irrigation, aerating, and mowing practices.

Revitalizing boxwoods in the North End Parks of the Rose Fitzgerald Kennedy Greenway. Top to bottom: late March, applying compost tea, early July. photo credit: T. Fleisher

T successfully uses organic management programs to restore the health of ailing landscapes. When the conventional strategy of adding more water, fertilizers, and pesticides to their dying boxwood hedges proved ineffective, the Kennedy Greenway Conservancy in Boston hired T as a private consultant. He soon discovered that the soil, recently disrupted by construction, had very poor natural nutrient cycling and was therefore unable to retain nutrients and nourish plants. Consequently, the boxwood root systems had weakened. T helped the Greenway Conservancy horticultural staff brew a bacteria- and protozoa-rich compost tea, which they injected into the soil.

Beneficial bacteria incorporate nitrogen into their biomass, preventing it from leaching out of the soil. Protozoa feed on these bacteria, metabolizing their carbon and nitrogen content at a ratio of 30:1. They release excess nitrogen as ammonium (NH₄) waste, a form readily utilized by plants. Their roots, in turn, exude substances that nourish bacterial populations. As the compost tea reestablished this natural nutrient cycle in the Kennedy Greenway Conservancy soil, the shrubs rapidly regained their health. Within two months, Boston enjoyed green, vigorous boxwoods in its newest park.

Gardener Nicole Lewis helps T prepare compost samples for biological content testing. photo credit: C. Robertson

Though T is skilled with advanced monitoring and testing equipment, he maintains that the best diagnostic tools are a spade, a soil corer, and his hands, nose, and eyes. Rubbing dirt from each of the three zones between his fingers and carefully examining its color, T made an estimate of the soil texture (the ratio of sand to silt to clay present) that almost exactly matched the UMass lab results: silt loam in the upper and lower thirds and loam in the middle.

Explaining that a very silty soil is an obstacle to easy infiltration, T was not surprised to hear that our cation exchange capacity (CEC) levels are low. CEC is a measure of the soil’s ability to retain and supply negatively charged nutrients such as calcium, magnesium, and potassium to plant roots. These nutrients cling to finely divided organic matter and clay particles in the soil. The microbes added to the soil in the liquid biological amendment (compost tea) will mitigate the effects of our low CEC by fixing these nutrients in their bodies. If their contribution is still not sufficient, we will add bulk compost to raise the level of organic matter present. The success of both efforts relies entirely on the quality of the compost we produce.

Casey Sclar, Ph.D. Plant Health Care Leader at Longwood Gardens, inspects a handful of compost from Swarthmore’s windrow at the municipal compost facilities. photo credit: C. Robertson

At the municipal compost facility, T and the other turf specialists reached into the middle of the maturing windrows, feeling the heat of the pile and extracting a handful of the rich, decomposing material for closer examination. In order to kill any weed seeds that might be mixed into the compost, the heap needs to be kept at a temperature of over 130º Fahrenheit for at least two weeks. If it strays above 160º, however, or does not receive enough air, anaerobic conditions alter the biodegradation process. The simplest method of detecting anaerobic compost, T taught us, is by smelling it: its hydrogen sulfide byproducts produce a scent similar to rotting eggs.

T, professors, Sustainability Committee members, turf specialists, and staff participate in a round-table discussion over lunch. photo credit: C. Robertson

In addition to discussing the technical details of our program, we also engaged T in a planning session on the study and documentation of our lawn care transition. Several professors and college community members joined us for lunch in a dialogue about prospective research projects, curricular tie-ins, and institutional assimilation. They entered a vigorous discussion about the feasibility and value of a scientifically rigorous approach versus a more qualitative life cycle assessment or demonstrative study. Regardless of which experimental design proves most suitable, we plan on monitoring changes in root development, thatch volume, turf density, soil compaction, irrigation requirements, and nitrates, phosphates, and pH levels in the soil and surface runoff. I will work with other students, faculty, and specialists to develop appropriate and replicable techniques to gather and analyze this data.

Examples of new equipment for the organic lawn project. From top to bottom: an Aeravator, lysimeter and hand pump, and a solar-powered rotary composter.

Based on T’s preliminary feedback and recommendations, the Grounds Department will begin researching and acquiring specific equipment, such as a pump for the compost tea brewer and an Aeravator to fracture deeply compacted soil with thin, vibrating metal tines. Andy Bastian ‘12, an intern with the Engineering Department, is hard at work assembling and modifying the design of two solar powered compost tumblers. Professor Carr Everbach is helping me calibrate and install a set of lysimeters to collect soil water samples to look at nutrient levels at different depths in the soil. By the time T returns in the early fall, our capacity to carry out and monitor an organic lawn care program will be significantly greater!

To learn more about T’s work, consider joining the Arboretum trip to Battery Park City Parks Conservancy on October 6^th or attending his next lecture here at Swarthmore at the Perennial Plants Conference on October 15th.

In the fall 2009, a New York Times article about an innovative organic lawn care project at Harvard University shook the assumptions of other higher education institutions regarding their own landscaping practices. A casual inquiry about Swarthmore’s lawn management by an alumnus who had read the piece sparked a flurry of discussion and activity that will culminate this fall in the implementation of the Scott Arboretum’s first organically maintained lawn.

Instead of applying standard synthetic herbicides and fertilizers to the five-acre field between Mertz dormitory and Magill Walk, gardeners will spread compost and spray compost tea. This organic matter will be carefully prepared and monitored to contain a balance of nutrients that fully nourish the soil, the microorganisms that dwell within it and, in turn, the grass. We currently use organic fertilizers and practice integrated pest management as a part of sustainability efforts. This summer we will begin testing organic lawn practices.

Based on favorable results at Harvard, we hope that our new lawn will improve the health of the turf and local ecosystem, minimize environmental impact by reducing mowing and irrigation needs, and offer a cost-saving alternative to conventional lawn care. Since the new approach requires closer monitoring and ongoing program adjustments, labor costs will rise; the cost of purchased supplies, however, will decrease. A project on a New York football field showed that once established, organic lawns can be 25% less expensive to maintain!

“A comparison of costs (dollars) for conventional and natural turf programs over a five-year period, based on data collected and analyzed by Charles Osborne and Doug Wood, Grassroots Environmental Education 2010.”

Next month, Eric T. Fleisher, the coordinator of Harvard’s organic turf program, will visit our campus to tailor his compost tea recipes, application schedules, and aeration techniques to the specific needs of our site.

A rising sophomore and student liaison to the Sustainability Committee this past spring, I received a grant from the Lang Center to work on the lawn care project with Grounds and the Arboretum. My first task was to run the diagnostic tests identifying the present makeup of the soil and turf upon which T. Fleisher will base his recommendations. Using the procedures that he prescribed, I have spent the past few weeks preparing soil samples for lab analysis and conducting percolation tests to determine the rate at which the soil is able to absorb water.

Camille Robertson digging soil samples to send in for laboratory testing. photo credit: N. Lewis

We have to wait for the UMass Amherst Soil Testing Laboratory to get back to us to learn the concentrations of organic matter and extractable nutrients, the soil texture, and the level of soluble salts in the soil, but the percolation tests returned immediate results.

Satellite image of Mertz field taken in 2008 during the construction of David Kemp Residence Hall. photo credit: Google Maps

To account for potential differences among the rates at which water infiltrates into the soil at different depths, I dug three foot-wide holes 6”, 12”, and 18” deep respectively. I then roughed the edges of each hole (so that water enters the soil as “naturally” as possible), lined the bottoms with sand (minimizing splashing, also a potentially confounding factor), and saturated the soil to control for dryness (making tests run the day after a rain comparable to those done in the middle of a drought). After completing these preparations, I filled the holes with water and checked them frequently over the next 12 hours, recording the height of the water column. Noting how quickly the water level drops allows us to infer the porosity of the soil—a more porous soil provides many channels for water, organisms, and roots to pass—an important factor in stormwater retention and turf health.

The 18” hole on Upper Mertz, 15 hours after the percolation test began. photo credit: C. Robertson

A healthy lawn percolates at one to two inches per hour. I conducted the three-hole test in each of three distinct zones of Mertz lawn; only the moist lowermost region drained this quickly. Since the second zone was subject to severe compaction by heavy machinery during the construction of the David Kemp Residence Hall in 2008, percolation rates were especially low there. Water infiltrated at only half an inch per hour. The upper zone, everything uphill of the old laydown area, exhibited intermediate characteristics.

I noticed other differences between the soils in each zone simply by feeling how hard it was to dig (the rocky Middle Mertz required a pickaxe), the general consistency and moistness (Upper Mertz was damper than Middle Mertz but drier than Lower Mertz), and the number and kinds of organisms I came across in the soil (so many earthworms in Lower Mertz!).

Understanding what creates a healthy soil ecosystem is the key to cultivating a thriving green lawn. The results of our diagnostic tests and observations will allow us to design an organic lawn care program that continues our tradition as “the most beautiful campus in the United States.”

Campers from the Chester Children’s Chorus play baseball on Mertz field. photo credit: C. Robertson

Our motivation behind this non-conventional approach lies in the bigger picture—fostering the health of the Crum Creek watershed and its human inhabitants. The college and Arboretum have always strived to be responsible stewards of both by following conventional best practices. But as Rachel Carson taught us, the unintended consequences of one decade’s practices may not become apparent until the next—some health effects of the chemicals we apply could take generations to become apparent, for example. Repercussions of our dependence on petroleum-based products will be magnified when the energy crisis truly sets in. In order to keep our community and environment healthy and sustainable, therefore, we are excited to push forward to tomorrow’s innovation: organic lawns! Check back with Garden Seeds as we describe our progress in developing an organic lawn maintenance program.

You may have noticed on the back of many catalogs and mailings from environmentally conscious companies, the FSC logo pictured above. The Scott Arboretum has been printing the Hybrid and many brochures and invitations with this logo since Fall 2006. The FSC logo is most recognizable on printed materials, but are you aware of what this logo represents?

Cover of the 2010 Spring Hybrid.

The FSC or Forest Stewardship Council logo indicates the publication has been printed on paper that has been harvested, milled, and printed in an environmentally responsible, socially beneficial, and economically viable way.

FSC oversees more than the production and printing of paper. It is an international non-profit organization devoted to encouraging the responsible management of the world’s forests. Thus the products certified by FSC are not limited to paper.

FSC logo stamped on MDF (medium density fiberboard) used in the construction of the Wister Center. photo credit. R. Robert

Because of the FSC’s commitment to environmentally responsible stewardship of our forests, it was a great source of building materials for the new Wister Center. Using sustainably harvested materials is a component of building a LEED-certificated building.

You can see FSC MDF being used as a building material in the skylight of the headhouse. photo credit: R. Robert

As a percentage of the total cost, 42% of the wood used in the Wister Center was FSC. These items can be found in the attractive Douglas fir decking, glu-lams, molding, and framing which accent much of the Wister Center. In addition FSC MDF (medium density fiberboard, an engineered wood product), can be found underneath many decorative elements of the Wister Center.

FSC douglas fir molding and framing was used to give the Wister Center its finished look. photo credit: Archer and Buchanan

]]> http://blogs.scottarboretum.org/gardenseeds/2010/03/fcs-wood/feed/ 0 http://blogs.scottarboretum.org/gardenseeds/2010/03/innovation/ http://blogs.scottarboretum.org/gardenseeds/2010/03/innovation/#comments Wed, 03 Mar 2010 18:46:15 +0000 Becky Robert http://blogs.scottarboretum.org/gardenseeds/?p=1925

When designing a LEED-certified building there are many strategies such as storm water management techniques, recycling materials from construction, and maximizing the use of natural light to light the building, that will help accumulate points needed to receive LEED certification. In addition to these established and recognized practices, the certification process awards points for innovation. This ability to innovate new green designs and techniques is what is driving the continually evolving green industry.

Upon embarking on the design of the Wister Center, there was much discussion about the techniques and the associated costs for heating and cooling the building in a…

When designing a LEED-certified building there are many strategies such as storm water management techniques, recycling materials from construction, and maximizing the use of natural light to light the building, that will help accumulate points needed to receive LEED certification. In addition to these established and recognized practices, the certification process awards points for innovation. This ability to innovate new green designs and techniques is what is driving the continually evolving green industry.

Upon embarking on the design of the Wister Center, there was much discussion about the techniques and the associated costs for heating and cooling the building in a sustainable fashion. An idea garnering much support as a sustainable technique, but an expensive method, was a ground source heat pump system. The majority of the cost for this proposal was in the drilling of several 100-foot deep wells beneath the site to serve as an area for heat exchange.

Thomas Cochrane and Rhoda Maurer discuss the inner workings of the Wister Center. photo credit: R. Robert

Following one of these discussions, Swarthmore College’s Senior Project Manager for Mechanical Systems, Thomas Cochrane, was struck with an innovative idea which addressed the needs of the whole campus, not just the new Wister Center. Dubbed the Total Campus Perspective (TC system) by the project engineers, this design provides a synergistic solution that benefits the Wister Center and the campus as a whole.

Ground source heat pump system illustration from the International Ground Source Heat Pump Association.

Using the ground source heat pump system during the winter months, water is circulated beneath the earth’s surface through plastic pipes and where it is heated by the constant temperature of the earth (50 to 55 degrees). This heated water is carried back into the building to the heat the space. During the summer months, the system is reversed. The water pulls heat from the building where it is discharged into the cooler temperatures of the earth.

Thomas Cochrane recognized the existing chilled water loop on campus could provide a similar function as the earth in the ground source heat pump system for the Wister Center. During the winter months, the Wister Center can use excess heat collected from other locations on campus where cooling is occurring (such as computer rooms, electrical rooms, and mechanical rooms) to heat the building.

Tapping into the heated water from the chilled water loop on campus offsets the operation of the central plant chiller which would be responsible for chilling the water. According to the project engineering team, there is a savings of 1,639 ton-hours each winter season for the central campus chiller plant.

Mechanical room where the TC system is housed in the Wister Center. photo credit: R. Robert

During the summer, the Wister Center rejects heat to the return side of the chilled water loop with the MacCabe library cooling loads, where the Wister Center is connected to the campus chilled water loop. It is estimated this adds 1379 ton-hours each summer season to the central campus chiller plant. Thus the net impact on the central chiller plant is an annual savings of approximately 260 ton-hours.

In addition to these savings, there is an earth exchange component to the system. Six hundred and fifty feet of buried piping that connects MacCabe Library and the Wister Center, aid in transferring heat to the earth. Therefore, it is providing further reduction to temperature of the water circulating between buildings in the summer and increasing the temperature the water in the winter, again benefiting the load to the central campus chiller plant.

The engineers estimate this innovative system is a 39% improvement over traditional rooftop air unit systems and a 1% improvement over traditional ground-coupled heat pump systems.  The TC system takes advantage of mechanisms already in place on campus to heat the new Wister Center and provide energy saving to the college as whole.

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Carex plantaginea. photo credit: R. Robert

At the Scott Arboretum, we have been trialing lawn alternatives for over 3 years. Our current favorites include Carex pensylanica, Carex laxiculmus Bunny Blue^TM , Carex flacca ‘Blue Zinger’, and Carex plantaginea. Check out more about our program and the plants we are trailing in the Green Design brochure. Read what sustainable garden writer Susan Harris had to say about our program and plant selections.

To learn more about re-envisioning our turfgrass lawns check out Virginia Smith’s article and her interview with Chuck Hinkle, the garden supervisor at the Scott Arboretum, who oversees our lawn alternative program.

Last week Yvonne Post’s lead goats, Wyeth and Rodin, visited the Scott Arboretum on a reconnaissance mission. As lead goats, Wyeth and Rodin (named for famous artists) are brought to trial new locations and vegetation to see if the entire herd would take to the site and eat the weeds found there.

Rodin chomping on ivy while Yvonne discusses goats in the garden. photo credit: R. Robert

Like many other institutions in the region, the Scott Arboretum is trialing the use of goats to remove invasive and stubborn weeds from the garden. Also called “nature’s weed-eaters”, goats are a sustainable, environment friendly way to treat weed infestations as opposed to chemical treatments.

Wyeth munching on ivy and leaves. photo credit: R. Robert

Post’s herd of six wethers, castrated male goats, have already begun removing Canada thistle, Cirsium canadense, at Bartram’s Garden. The herd is also hoping to visit Longwood Gardens to help remove garlic mustard, Alliaria officinalis. Post has described how they delight at eating mile-a-minute vine, Polygonum perfoliatum, on her property. Here at the Scott Arboretum, we are working on removing English ivy, Hedera helix.

This trail evaluated whether the goats will eat the ivy blanketing the banks of the Crum Woods or whether they would graze on other plant material. We are happy to report that after settling into their new surroundings in the woods, Wyeth and Rodin blissfully chomped away on ivy and fallen leaves. The complete herd of Angora goats will return this January to begin foraging on the ivy in earnest.

Goats are more effective at weed removal than other grazers, such as sheep. Goats rip and pull the plants out by the roots when they forage, as compared to sheep who simply graze the tops of the plants, leaving the roots intact. Post recommends having the goats for three consecutive years to see true effect on a weed patch.

Rodin and Wyeth over looking the smorgasbord of ivy. photo credit: R. Robert

Goats prefer to feed on different plants at various times of year. As Post explains, “They get bored.” As you can image with ability to eat such a variety of food, you would like to spice up your diet too. They enjoy the young shoots for Canada thistle in the spring, mile-a-minute vine in the summer, and fallen leaves and weedy grasses in the fall. For this reason, the herd will visit the Scott Arboretum in the winter feeding on the smorgasbord of ivy. This way the herd will not be distracted by more choice plants found during warm months and allowing them to focus on controlling our English ivy infestation.

On Thursday, October 22 over 35 volunteers from Swarthmore College, Scott Arboretum, and CRC Watershed Association gathered to plant 83 trees and shrubs. These plantings were the result of a TreeVitalize Watershed Grant awarded from Pennsylvania Horticultural Society (PHS) and Delaware County Conservation District (DCCD). Volunteers spent the morning planting a 2,000 square feet or 4.59 acre riparian forest buffer along the Crum Creek corridor.

Tools and plants are laid out in preparation for volunteers. photo credit: R. Maurer

These plantings were in addition to the trees planted last spring by Swarthmore College volunteers in the area newly name Roger’s Grove, which is the area south of the train tressel. These efforts are part of a study done by the biology department, professor Jose-Luis Machado, delineating knotweed populations and lacking native plant buffer.

Along this corridor of the Crum Creek, the invasive knotweed, Polygonum cuspidatum, forms dense thickets that exclude native vegetation. As a riparian area (an ecosystem that occurs along a watercourse or water body), the banks of the Crum Creek are under significant threat from knotweed because it can survive floods and then rapidly colonize scoured shores before native vegetation can establish.

Polygonum cuspidatum is an upright, shrublike, herbaceous perennial that can grow to over 10 feet in height. It produces minute greenish-white flowers that occur in attractive, branched sprays in summer and are followed by small winged fruits. The root system consists of long, stout rhizomes.

The brown stand of plants behind the volunteers is treated knotweed along the creek bank. photo credit: R. Maurer

Because of these rhizome roots, knotweed should not be removed by digging up the plants. The rhizomes will simply break or be cut apart creating new plants. In order to control the population along the Crum Creek, glyphosate (an herbicide) was applied twice to the foliage of the plants, once in the late summer and another in early fall.

Volunteers planting the riparian forest buffer. photo credit: R. Maurer

Volunteers then planted the riparian forest buffer with native species to shade out and, once established, out compete the knotweed adjacent to treated to treated populations of plants. Bryn Richard, a local landscape architect, selected the native plants according to the Wetland Indicator Status from the USDA plant database.

Anne Murphy and Bryn Richard of CRC Watershed teaching volunteers proper planting techniques with a weed mat. photo credit: R. Maurer

This indicator identifies if a plant occurs almost always, likely, usually, or equally likely in a wetland. From this indictor Byrn located native plants closer, further, or on a raise adjacent to the creek bank. See the complete list of plants and their indicator below.

If you visit this new planting, you will notice they are planted in rows 15 to 20 feet apart. Many of you may notice this is opposite of what is recommended to homeowners. The rows are to allow mowing of the meadow two to three times a year until the plants are established. They were also planted close together to quickly create a canopy of shade to shade out the knotweed.

Tube protecting a tulip poplar from deer damage. photo credit: R. Maurer

These young plants were also planted with a weed mat to discourage weeds, and a deer cage or tube to prevent additional damage. Once the plants reach an appropriate size volunteers from the CRC Watershed Association will remove the cages and mats.

If you have a canopy of knotweed growing along a bank near you, you can apply for a 2010 Southeast PA TreeVitalize Watersheds Grant Program. Applications are due to the Delaware Co. Conservation District before Friday, November 13th.

Thank you to all the volunteers, Bryn Richard, Anne Murphy, and CRC Watershed Association for helping to make this project a reality. And of course to PHS and DCCD for providing the support for this restorative effort.

If you have ever read, watched, or listened to any tips on greening your life, one of the first recommendations given is to turn the lights off when you leave a room and, if you want to go the extra mile, change your light bulbs to energy efficient bulbs. Thus it is no surprise that all the light fixtures and features in the Wister Center maximize energy efficiency as we strive to achieve silver LEED certification.

In my attempts to quantify our total electrical savings with light fixtures and light controls, Brad Randall, an engineer on the Wister Center, informed me that the final number will be determined based on actual occupant usage. In other words, we won’t know our true savings until we begin to use the building.

In the meantime, Brad estimated we will save a minimum of 10% on electrical energy as compared to the typical new building. He is expecting the actual savings to be much higher if the lights are used less often or remain off when daylight is sufficient.

Numerous windows allow for daylight to light the interior of the building and provide a great view into the Terry Shane Teaching Garden. photo credit: R. Robert

The Wister Center maximizes the use of daylight to light the building in two ways. The building was designed with numerous large windows, allowing for ample daylight to enter the building and provide great views into the gardens. We have also installed four light tubes.

Light tubes and CLF lamps line the volunteer hallway. photo credit: R. Robert

Light tubes capture light through a dome on the roof, then funnel this light through a reflective-lined tube, where it is finally projected through a transparent ceiling lens. What makes these tubes so effective at gathering daylight and projecting it into the building is the tubes are lined with a reflective surface to bounce the light along the tube.

These tubes line the enclosed hallways of the volunteer corridor in the Wister Center. I have been in the Wister Center on the numerous cloudy days we have been experiencing of late and didn’t even notice that only the light tubes were lighting this enclosed space. I would have thought the fluorescent lights were on.

Chandeliers in the Gillespie Room contain energy efficient ceramic metal halide lamps. photo credit: C. Sawyers

In addition to harnessing daylight to illuminate the Wister Center, we have chosen energy efficient lighting fixtures. The majority of the lights in the center are T8 fluorescent or compact fluorescent (CLF) lamps. These are the types of energy efficient light bulbs found in grocery and drug stores that you can purchase to replace light bulbs in your home. CLF bulbs use 75 percent less energy and last about 10 times longer than traditional incandescent bulbs.

The 8 chandeliers throughout the building use ceramic metal halide lamps. Like other gas-discharge lamps such as the mercury-vapor lamps, they produce light by passing an electric arc through a mixture of gases. Ceramic metal halide lamps were chosen because they are more efficient than halogen lamps, have better color quality, better lumen maintenance, and better color consistency.

The biggest drawback is it requires a restrike time. In other words, if you accidentally turn these lights off you must wait until the bulbs cool to turn them on again. These lights are typically used on athletic fields, in high-end professional lighting fixtures, and by reef aquarists.

In addition to installing energy efficient light fixtures, we have installed mechanisms to minimize the amount of time these lights are on. The building operates on a relay based microprocessor low voltage control system. This system turns the lights off and on at pre-programmed times of the day. Thus we are not using various light fixtures when people are not occupying the building. All of these fixtures are controlled by a touch panel which allows occupants to override any pre-programmed settings if need be.

Occupancy sensor located in a storage closet at the Wister Center. photo credit: R. Robert

There are also numerous occupancy sensors throughout the building in spaces like the kitchen, restrooms, storage rooms, office, and janitor’s closet. Occupancy sensors turn the light on when the sensor senses movement within the space. If it does not sense movement after seven minutes (the timer is adjustable.) the light will turn off. These sensors eliminate the worry of forgetting to turn the light off. All the light switches have an override if the sensor does not recognize your movement within the space.

We are excited to see our true energy savings once we begin use of this building. Join us for our first public event in the Wister Center, titled “The Story of Wister Center” on Thursday, November 12 at 5pm. Architect Dan Russoniello will discuss all the LEED certification efforts for the Wister Center.

Another way to achieve LEED certification points is to reuse building material and recycled material. For the Wister Education Center and Greenhouse this idea has been employed in several avenues but none as uniquely as in the use of Metasequoia shingles.

Citilog unloading the Metasequoia trees in their lumber yard. photo credit: Citilog

In order to build the Alice Paul Hall (opened in 2005), a grove of Metasequoia glyptostroboides, dawn redwood, was removed from the area beside the south end of Mertz Hall. These twelve trees were harvested by Citilog and milled into shingles.

Stack of harvested Metasequoia trees. photo credit: Citilog

Citilog takes trees that have fallen down, are being removed as part of a construction project, or are saved from a demolition project and creates finished wood products such as furniture, flooring, and architectural millwork. Their mission is to “save trees from being dumped into landfills, cut for firewood, or ground up for mulch. In the process, they provide a valuable source of quality lumber, cabinetry, millwork and a wide variety of finished wood products.”

Metasequoia shingles on the Wister Center. photo credit: R. Robert

For the Wister Center, we were able to use 381sq. ft. of the Metasequoia shingles and used a 100 sq. ft. of cedar shingles to complete the job. We are amused to think outside of China, we may be the only place to have used Metasequoia in this way.

Click here to read about all the efforts for LEED certification at the Wister Center.

Almost a year after planting Swarthmore College’s and Scott Arboretum’s third green roof, the plants have grown together to create a striking tapestry of color. Check out what Jennie Love had to say about our green roof after visiting this summer.

A tapestry of sedum on the Kemp Hall green roof. photo credit: D. Mattis

There are two more green roof tours left this season. Mark your calendar for Saturday, September 26 and Thursday, October 22 to experience the parade of colors created by Sedum, Talinum, Delosperma, Campanula, Allium, and Dianthus. We hope to install our fourth green roof on the Wister Education Center and Greenhouse this fall. Stay tuned to Garden Seeds for updates.