A luminous garden-under-glass celebrates the beauty and resilience of a global ecoregion where water is increasingly precious.

Longwood Gardens West Conservatory

Kennett Square, Pennsylvania

The Garden of the West Conservatory brings an entirely new horticultural experience to Longwood’s world-renowned collection of gardens-under-glass. At 32,000 sf, the garden celebrates the particular beauty of species that thrive in the Mediterranean’s dry climate and expands visitors’ understanding of one of our planet’s most diverse ecoregions—its beauty, mutability, and resilience.

Longwood’s Crystalline Ridge.

The main garden at Rastrapati Bhavan (above left) and the close relationship of stone and plants in the Mediterranean (above right) were inspirations.

The new garden both reflects and reimagines the presence of water (above) and approach to garden circulation (below) within the historic conservatories.

Planting zones studies 2 — A set of early concept diagrams looks at diversity and distinction in the structure of the planting design.

A Legacy of Water Gardens

Building on Longwood’s tradition of fountain gardens, the West Conservatory Garden inverts the model by setting the West Conservatory on a 21,000 sf reflecting pool. Inside, water continues to structure the garden. Guest paths hover above threaded waterways and stepped pools, fashioning three islands, each carpeted by a composition of low shrubs and perennials from the globe’s six Mediterranean ecoregions. The garden is intentionally not focused on the expression of a distant ecosystem or on seasonal display. It is a true garden where stone, water and plants are carefully calibrated to create a unified work.

1 longwood gardens fountains mountain dreams

The Italian Water Garden.

Early in the process, physical models of varying refinement helped guide proportions and geometry.

To test the design of the gardens' water elements, during design development the construction manager built 1:1 mock-ups so the team could evaluate scale, depth, water action, and material selection.

The interior and exterior pools' 350,000 gallons are continually recirculated through a biofiltration system supplemented by UV treatment. Water lost to transpiration is replaced by treated roof water collected in below-ground tanks south of the conservatory, part of a larger water conservation system.

The garden weaves varying expressions of water, stone and plants — elements both distinct and inextricable within the Mediterranean ecosystem.

Construction Process IMG 0473a — Although the garden’s islands appear continuous, they are actually individual beds defined by structural walls clad in cast stone. The beds support a complex infrastructure that feeds the pools and maintains optimal soil temperature and moisture levels throughout the year.

A Mediterranean Tapestry

The planting design for the garden is expressed at varying scales. Groves of Bismark Palms (Bismarkia nobilis) and Willow Acacia (Acacia salicina) provide height, shade and a dramatic contrast of character. Rows of Italian Cypress (Cupressus sempervirens) and Bay Laurel (Laurus nobilis) intensify moments of hide and reveal. The counterpoint to the more orthogonal structure of the garden's largest plants is a composition of low shrubs and perennials carpeting the three islands. This tapestry includes over 60 permanent species, many with billowy forms and small leaves, reflecting the plants’ way of responding to climates where water is precious.

Custom stainless steel growing structures, including trellises for citrus espalier and angled structures that allow flowering vines to cantilever over the south walk, reflect the Old-World tradition of training plants and put a point of emphasis on Longwood’s own skill in cultivation.

The garden’s plants were sourced and contract grown across California.

The garden’s permanent collection includes over sixty different species from across the globe’s six Mediterranean ecoregions.

Shifting Character

The garden has different characters throughout the year. At times most of the garden will be in bloom, at others, foliage will be the dominant expression and texture and hue will rule. Those varying expressions will be supported by up to 5 different seasonal components (including over 90 individual species), whose addition will expand the beauty of the garden and the diversity of the guest experience over the course of a year.

WC Plan PLNT 07 SEASONAL ALL — Plan of the gardens seasonal elements (in red).

The garden’s varying seasonal inclusions – ground planting, aquatics, demountable columns and hanging structures are designed to be used in varying combinations to enhance change in the garden throughout the year. Spring (top left), Summer (top right), Autumn (bottom left), Christmas (bottom right).

A Unique Garden Under Glass

The soaring transparency of Weiss Manfredi’s conservatory is in startling contrast to Longwood’s historic houses and reinforces this garden’s unique expression within the collection of gardens-under-glass. This garden is in closest conversation with the landscape around it as it connects water to sky.