By Cat Meholic
Curatorial Horticulturist, Ambler Arboretum of Temple University
The Cottage Hall Courtyards are those gardens surrounding the footprint of Cottage Hall. There are many large and small gardened areas. They tend to feature native plants and provide many quiet garden spaces. Being responsible for the management of the Cottage Courtyard Gardens, I wanted to take you behind the scenes of the care of one tiny space in these gardens.
One of my favorite areas that I manage is also one of the smallest and least known areas at the Arboretum. It is a tiny courtyard at Cottage Hall that you access from the Wetland Garden. What this courtyard lacks in size it makes up for in charm. Three small concrete benches are positioned around a quaint brickwork patio. This patio has carved pavers set into it that depict the tools used in horticulture and landscape architecture. The small scale of the space doesn’t stop trees from growing there either! Redbud (Cercis) is the dominant tree in the space, but an ash has taken up residence as well. The groundcover is mostly blue sedge (Carex laxiculmis) and Christmas fern (Polystichum acrostichoides), but we hope to add more diversity to it in the coming spring.
I selected this area as a behhind-the-scenes topic for two reasons. First, to discuss the concept of garden size vs. maintenance requirements, and second to answer a question I get all the time, “What do you do during the winter months?” First things first, let’s talk about size vs. maintenance. The courtyard is only 10-feet by 20-feet (or 200 square feet) and is considered a low-maintenance design. A third of the space is covered in brick, leaving about 135 square feet of planted garden. This planted area only requires periodic weeding. However, over the last week, myself and two volunteers have spent a total of six hours cleaning up this small space. Our tasks included weeding, pruning, and raking out leaves. We hauled out enough debris to fill four loads in the Arboretum’s Gator. The Gator has a bed space that is 48-inches by 42-inches. After a little math-e-magic, we removed enough debris to cover almost half the area of the planted garden space. This doesn’t even account for the depth of the loads we were removing!
So, where does all of this debris come from, and what happens to it? The debris is mostly leaves, from both the immediate trees and those surrounding Cottage Hall. Broken sticks and twigs accounted for a large part of this material, but a large part was intentionally pruned woody material. As to what happens to this garden debris next, we compost it here at the Arboretum. All of the material we removed from the courtyard is organic and, if properly composted, becomes a fantastic soil amendment that adds organic material back into the garden without ever leaving the campus. Part of our winter work this year is planning how to make our composting system more effective and still ensure our plant debris never enters the landfill. We will keep you posted as we work through that process.
I’m hoping that by reading this, you’ve already started to piece together what a horticulturist does during the winter; clean up garden debris, prune, and plan. Pruning is a top priority during winter as the shape of the plant is more obvious, and the cold weather minimizes the possible development of diseases infecting the pruning cut. We make judgment calls in each of our garden areas about how much herbaceous material to cut back or leave in place. In the naturalistic areas of the Arboretum you’ll see loads of herbaceous material left up all winter and beds thick with a blanket of leaves. This is to support wildlife that burrows into stems to overwinter or feed birds and small mammals with remnant seed. In our most formal areas you’ll see herbaceous material cut to the ground, but there are ample resources left standing for wildlife surrounding these gardens. In our moderately formal areas, you’ll see an intermediate strategy; plants that are upright and look aesthetically pleasing are left in place, and where we choose to cut material back, we cut it 12 to 18 inches from the ground. This ensures enough structure is left for insects to comfortably overwinter in the cut stems. Often in these intermediate area the leaves are run over with a mower to chop them up and then used as a mulch to cover the soil. This ensures the nutrients are returning back into the soil, but mowing over the leaves gives it a tidier aesthetic and helps them to break down faster.
We invite you to visit the courtyards at Cottage Hall on your next visit, and see how they change over the seasons. Perhaps you’ll also be inspired to put on your “winter horticulturist” hat and gloves to plan how to balance the aesthetics and ecological functions in your home garden. Maybe leave herbaceous plants up a little longer than you normally would, experiment with leaves as mulch, or even implement a composting system in your home garden! Just like small gardens can make big compost piles, even small efforts in a garden make a big impact on our natural world. Happy winter gardening!