Hilltop Edge Habitat Fit for a Public Garden | Fairfield County, CT

Expansive and unique, this project had to make our top three landscape design projects of 2024. Sited atop a hill in Fairfield County, Connecticut, the property already had extensive landscaping. The client approached us with a very specific objective: designing a garden around a custom gazebo in the lawn, with a woodland border underplanting behind it. The massive garden becomes an edge habitat and flyway between the woodlands encircling the four-acre property, an essential link between larger habitats. The scale, at almost an acre of new gardens, represents a massive addition of biomass and biodiversity – an ecological achievement in itself!

Newly planted gazebo garden extends the woodland edge habitat and offers immense biodiversity.

Harsh Hilltop Site Conditions

 The stunning hilltop location comes hand in hand with challenging site conditions. It sits at a higher elevation, atop a plateau on the hilltop, where winds are stronger, and the resulting microclimate is colder and drier. Within a rural zone of Fairfield County, the historical land use was agricultural and logging, which influenced the current soil profile.

The site: an expanse of lawn, mature oaks surround the gazebo, with a steep wooded drop off the hillside behind.

Soils on top of a hillside are more prone to erosion – from wind, stormwater, and the gradual depletion of soil from traditional maintenance practices like removing lawn clippings and leaves (that provide essential organic matter for creating new topsoil).

Gorgeous view of a nearby lake is a reminder of the fragility and ripple effect of this landscape environment.

The four-acre property is in proximity to three major river systems and includes wetlands, woodlands, pasture lands, and an expansive lawn area. The lawn, from a bird’s perspective, is a dangerous open land offering no food source, no cover, no nesting materials, and no water. It is a high stakes flyway between two valuable habitats, where they are most vulnerable to attack from predators. Bridging these environments with an edge habitat and safe, vegetated flyway has enormous potential for extending wildlife habitat.

A Client with a Vision

When we arrived on site for the consultation, the client had already staked out his desired landscape area. It centered around a massive custom gazebo in the lawn, with four amorphous quadrants extending from it, leaving space for four mowed paths dissecting them. A mature oak in one quadrant also had an existing swing hanging from its branch, that swung perfectly through one of the mowed paths – well thought out!

Staked out quandrants and paths, with the existing swing and gazebo.

Just behind the gazebo garden, the woodlot begins and drops steeply down the hillside. The client had an existing trail system and wanted to add underplanting at the woodland border and along the initial stretch of trail.

Before: woodland border is filled with garlic mustard and other invasive species.

The scale of the proposed garden and the grandeur of the existing gazebo are on par with public spaces like botanical gardens and public parks. What a treat to work on such a project!

Designing an Edge Habitat and Savanah Landscape

The site receives a range of light conditions, from deep and dappled shade in the woodland to part shade to full sun throughout the gazebo garden. This variety of microclimates offers immense opportunities for biodiversity and, on the flip side, can make continuity throughout the landscape more challenging. With over 1300 plants planted, we aimed to strike a balance between biodiversity and visual legibility.

Plant delivery! Staging 1,300 plants for placement in the garden is no small feat!

The woodland underplanting palette is heavy on native shade-loving shrubs like dwarf fothergilla, itea and dogwood. Interspersed with the shrub groupings are masses of native ferns, sedges and wildflowers.

Woodland Edge Habitat planting plan, designed and installed by Green Jay Landscape Design.

Bloom periods for woodland natives are often shorter and concentrated in spring, so choosing plants with enduring foliage interest, or appealing visual succession (ie. from flower to berry) pack more visual punch.

Gazebo planting plan, designed and installed by Green Jay Landscape Design.

In the gazebo garden, a mix of ornamental grasses and native perennials form a tapestry of color and habitat. Given the light conditions, the grasses were concentrated in the sunnier quadrant which faces the home, creating a frame and structural support for the perennials behind. With the mature oak anchoring the garden, the plant palette takes on the aesthetic of a savannah, a type of grassland interspersed with trees.

Newly planted gazebo garden.

We like to think of the gazebo garden as the birds’ shopping center: it is so jam-packed with biodiversity, specially chosen for their continuous sequence of food unfolding throughout the season. There is something for everyone, at every time of year. Butterflies and bees pollinate the perennials; birds eat the caterpillars, seedheads and berries; the cycle continues.

Baltimore Oriole taking shelter in a newly planted Hydrangea shrub.

We also peppered in larger Viburnums through the gazebo garden, essentially acting as bird islands, with their mass of branches, flowers, and berries.  It is important to include larger woody shrubs to help transition birds from the upper canopy to the lower garden safely. Woody plants have the added benefit of creating spider habitat – their branching structure supports spider webs – which act as natural pest control in an organic garden.

Boulder accents are an important ingredient for multi-season interest.

Boulder accents, repurposed from old farming walls on site, were placed throughout the gazebo garden to create contrast among the plants and structural winter interest. Plus, they are very low maintenance. We also reclaimed fieldstone from the woodland and used it to line and define the existing trail.

Placed plants along the woodland edge habitat connects the woodlands habitat to the savannah habitat.

Planning an Efficient Installation

Garden areas of this size require careful planning to ensure an efficient install that does not leave bare soil exposed for very long (bare soil is ripe for erosion). In this case, we brought on extra crew members to remove turf from the garden zone with sod cutters.

Crew members use sod cutters to remove turf grass.
Garden area de-thatched and ready for grading with new engineered topsoil.

Removing turf is relatively efficient when it is on a flat enough plane to use a sod cutter. Since turf only has about three inches of root depth, it can be cut away and rolled up like a carpet. However, you must be fastidious in removing any clippings that may fall in the process, as they will create a maintenance headache down the road, ass grass begins to germinate in the garden.

We were fortunate to be able to compost the turf on site in a portion of the woodland, which made the project more efficient altogether.

Given how vulnerable the site is to erosion, the remaining soil depth once the turf was removed was too thin to ensure successful establishment of the new plants. We graded about fifteen yards of soil throughout the gazebo garden and woodland edge habitat. Most native plants require 6” – 1’ of root depth, so we wanted to plant into at least 3-4” of good soil to start. Again, the added crew members helped us to efficiently spread the soil and prepare the area for planting.

GJLD crew removing invasive vegetation from the woodland border to prepare for planting.

Habitat-Specific Soil Amendments

As organic land stewards, we take our soil amendments very seriously. Organic fertilizer, bio-stimulants, and compost are key component of our organic program. For this project, we tailored the soil amendments for each zone. Perennials and herbaceous plants tend to cultivate a bacteria-based soil microbe support system, while woody plants cultivate a fungal-based soil microbe support system. Knowing this, we applied slightly different products to each zone to cultivate the right kind of microbial communities for our designed plant communities.

Prairie plants, like our native ornamental grasses and other charismatic native perennials, prefer very lean soil, so we omitted compost for this section of the garden. We also added sand around some of the native grass plantings to better imitate the prairie soils.

Newly graded and amended gazebo garden beds are ready for planting!

By choosing a leaner soil type when grading the project, we ensured we weren’t over-enriching the soil. Side note: most commercially available soil is made by mixing soil dug from a foundation of a building project with leaf and brush compost. While this may be an economical model, it results in soil with 30-40% organic matter! Most plants prefer 10% at most, and many native plants even less. By purchasing a more mineral soil blend, we can better control the quantity and quality of compost to add.

The client had collected leaves from the property and stored them in a compost pile. We repurposed it as mulch for the woodland garden, creating a slow-release drip of nutrients and protecting bare soil.

A Savanah edge-habitat fit for a botanical garden!

Best Landscape Designs of 2024

This project is part of our count down of the Best Landscape Design Projects of 2024, ranking #3!

Read about the rest of the top five:

#4: Restoring Functionality & Reducing Erosion on a Steep Slope

#5: Nature Play at Home: Designing a Backyard World of Wonder

Interested in improving your landscape? Contact us for a consultation!