The 2023 cohort of Hunnewell horticulture interns at the Arnold Arboretum of Harvard University spent some of their summer restoring and renewing a historic pathway between the Hunnewell Building lawn and Leventritt Shrub & Vine Garden.
The Arboretum’s first bridle path, named so because it was created as a thoroughfare for horseback riders, was laid out in 1928. Over the past century, as institutional priorities shifted, maintenance and use of the path declined.
Revitalizing the bridle path offered the interns the opportunity to improve visitor access, restore areas damaged by poor traffic control, and re-envision planting designs to align with the Arboretum’s current curatorial practices.
Research and planning took up the first part of the summer. After learning about the historical bridle path in our library and archives, the interns conducted an assessment of the path’s condition, noting soil compaction and composition alongside root zone damage of several trees.
Next they assessed the plantings along the path, noting plant height and shade cover. Combining field data, GIS data, and satellite imagery, they approximated the canopy model of the site using Rhino software. From this model, they created a shade study, identifying pockets of dense shade, open sun, and gradients in between to devise a new planting plan.
Working with the curation, horticulture, and greenhouse teams, the interns carefully identified plants for removal along the proposed pathway. Arboretum greenhouse staff took softwood cuttings from select specimens for repropagation in our greenhouses to preserve these lineages. Removing some plants either duplicated elsewhere or of low importance to the collection created new viewsheds and opened space for a new shade-loving shrub collection that will be planted over the next year and complement similar collections in the Leventritt Garden.
To better define the pathway and cushion the tread of visitors, interns worked with the horticulture team to lay more than 100 yards of mulch over some 1,000 linear feet of pathway in just two days.
One task remained as their internship drew to a close. After the mulch was laid, portions of the old, compacted path were still visible on either side of the pathway. The interns worked to remediate the soil on either side of the path to make it fit for planting. First an air spade was used to break up the soil, then it was fortified with a few inches of loam. The interns’ suggested planting plan for the path will be incorporated into the living collections team’s fall and spring planting strategy.
The resulting pathway has immediately been put to use as visitors meander along new and familiar viewsheds. Thanks to the Hunnewell interns’ hard work and careful planning, the Arboretum has a fresh take on a historic pathway, and with new opportunities for exploration along the way.