Digging Deeper



Digging Deeper

Digging Deeper

When we opened our doors to the public in 2007, our facilities were designed to accommodate 40,000 annual guests. In 2018, we welcomed 220,000 visitors. Even in that first year, it was obvious that we were rapidly outgrowing our original Visitor Center. Over the years, the space was retrofitted to increase office area and better utilize the remaining space for the benefit of guests. In addition to re-configuring the Visitor Center, the Bosarge Family Education Center was built to provide more education space and house additional staff. However, between 2007 and 2017, our staff grew from 10 full-time and 12 part-time/seasonal to 52 full-time and 50 part-time/seasonal, while visitation increased five-fold. It became clear that no amount of additional retrofitting could solve what is essentially a problem of space. To ensure our infrastructure is able to support current as well as future visitation, we’ve begun implementing phase two of the master plan. The master plan builds capacity to serve current and future guests, while also creating additional space for education, horticultural research and a growing staff.

Visitor Center + Discovery Bridge

Construction of our current Visitor Center was completed in the spring of 2018. Landscape architects Nelson Byrd Woltz, known for their ecologically sound design, sited the new building in a former parking lot. Designed by Steven Blatt Architects of Portland, this two- and three-story shingled building provides three times the square footage of the older, single story visitor center while utilizing practical, sustainable passive building standards.

Guests enter through the central lobby with access to an expanded membership area, guest services, an information kiosk, restrooms and the Gardenshop. The Snack Shack, complete with open-air seating, is located on the terrace behind the VC. Groups have a dedicated entrance near a bus parking area. Staff and volunteers enter though a separate side entrance.

The first and second floors of the building contain offices and communal space for staff and volunteers. The third floor features a meeting room that can seat 75. We have incorporated 30% more office space than we currently need in order to provide a buffer for growth.

A bridge is a strong metaphor, suggesting both a threshold and a connection between two places. When guests exit the Visitor Center, they cross a 200-foot long, 12-foot wide pedestrian bridge spanning a large, forested wetland.

While this bridge serves an important practical role in protecting a unique wetland area, metaphorically speaking, it provides a wonderful transition to the joy of the gardens and nature beyond. The bridge is constructed like the marine piers so common in the area, but uses ecologically-friendly, rot-resistant black locust rather than pressure-treated or synthetic wood for decking. The bridge provides a safer experience for pedestrians, separating them from cars, buses and our accessible shuttles.

Entry Court and Gardens

The entry court and gardens adjacent to the Visitor Center feature a blend of native and ornamental plants, as well as stonework inspired by our Maine landscape set amid a brick terrace. There is also accessible parking and a drop-off area.

With nearly an acre of planting area, the entry gardens fall somewhere between our Lerner Garden of the Five Senses and the Bibby and Harold Alfond Children’s Garden in size and serve as a beautiful introduction to all we have to offer at CMBG. The garden beds also include riverbed stones to collect stormwater run-off. This run-off, after being filtered, replenishes our natural wetland areas.

Parking and Infrastructure


Our original parking lots consisted of four gravel “pods” that could accommodate a total of 125 cars. In response to the unexpectedly high visitation we experienced, our parking areas were expanded to provide spaces for a total of 340 cars. These spaces regularly filled on high summer days and during Gardens Aglow, due both to the increase in visitation and to a three-fold increase in length of stay as more garden areas have been added and guests linger longer. Non-visitor pressure on parking has increased greatly, too: staff has quadrupled, and there has been a similar trend among volunteers. Expanded educational offerings and more field trips have put further pressure on parking.

A better solution than dusty gravel lots was a top priority for phase two of the master plan. To that end, we converted the original lots into gardens or as sites for the new Visitor Center and, later, the Conservatory. The topography allowed us to create a tiered set of parking pods separated by 15-20 foot planting zones. The new parking area consists of 12 individual pods, including accessible parking spots and separate spaces for staff and volunteers. A separate bus parking area accommodates buses and RVs.

The main parking areas have been constructed using porous asphalt, a technology that allows stormwater to flow through the asphalt to a retention basin beneath that’s designed to capture and filter rain from a 25-year storm event. The basin is filled with coarse gravel above and fine gravel below. As stormwater flows through the gravel, pollutants and sediments are removed and the velocity of the water is greatly reduced. Treated stormwater eventually makes its way to pipes at the bottom of the basin where it is slowly discharged into the forest beyond.

Plant Nursery and Horticultural Research Center + Homestead

Towards the southern tip of the property lies the foundation of an old farm homestead. This will be the site of a new plant nursery that will allow us not only to grow more of our own plants on site for our gardens, but also to develop and test new plants for northern landscapes. This important part of our mission – research – has been the piece we have long dreamed of fully implementing, creating opportunities to better document Maine’s beautiful rare native species, to study the spread of species from the south due to a changing climate, and to develop plants that are better suited for our northern and coastal landscapes.

The nursery will also include an herbarium and botanical research program focused on wild plant diversity and conservation in the MidCoast region. Studies of this kind have not taken place in this area for many years, and the landscape has changed since nineteenth-century botanist Kate Furbish first collected, classified and illustrated Maine’s native flora.

The homestead will also be rebuilt to provide a space for learning and classes with a stronger emphasis on food and food security. This will include demonstrations of year-round, home-scale fruit and vegetable production, as well as classes on preserving and serving these foods and more. This will also be an area that will provide a continued focus on sustainability, including expanded composting, water conservation and alternative energy projects.

Expanded Education Campus

Our current education area will benefit from the eventual addition of an expanded education campus around it. This campus will include our current education building, a new youth education building and a “wet classroom” for hands-on learning, an expanded facility for our Horticulture Therapy program and a Center for Professional Horticulture. The Center for Professional Horticulture will provide vocational and continuing education for green industry professionals and those seeking a career in the fields of public horticulture, lawn care, landscape design and installation, nursery management and arboriculture.

Conservatory + Pond, Bog and Stream Gardens

A glass conservatory will be the cornerstone of our efforts to build year-round visitation, jobs and opportunities for our area. The conservatory will create a space for late-winter and early-spring shows, such as specialty orchid displays and butterfly shows, during a time of the year when not much else is in bloom. Based on the shape of the classic saltbox home, the conservatory will be specially built for cold Maine winters while still providing an environment for out-of-season plants.

Utilizing an innovative double-layered energy curtain to reduce heat loss in the colder months, the conservatory will also feature passive natural ventilation and cooling to remove the need for forced cooling in the summertime. Featuring cold-tolerant plants in the wintertime will also help to keep our heating costs low.

The conservatory and a 250,000-gallon pond and surrounding gardens will be installed on the site of a former parking lot. This pond will include a pump station and will be available 24/7 to local first responders. A stream and bog garden will also be added, expanding the diverse plant communities on our property and creating better habitats for wildlife.

Restaurant Pavilion

To catch up to current visitation numbers while also providing a buffer for growth, we decided to convert our original visitor center into a restaurant pavilion. The concept is to retain the character and footprint of the original building, but to expand the kitchen into the former offices and convert the lobby, ticketing area, conference room and former gift shop into healthy, family-friendly, buffet-style service and seating. The existing café space will become a separate, more intimate restaurant featuring table service. Eventually, a three-season structure will be erected on the terrace outside and will serve pub-style food and drink.