Old Canaan Building Materials

Topiary — the shearing of woody plants into geometric or figurative forms — has been practiced in New England gardens since the colonial period. It is not a whimsical detail. It is an architectural intervention: a wall of clipped yew is as structural in a garden as a stone wall. The species matters. Boxwood is the default American topiary plant and it is the wrong choice for New England. English yew and European hornbeam are the correct choices.

English yew (Taxus baccata) clipped into a hedge or geometric form reads as dark, dense, and permanent. Its near-black green is the darkest green in the garden, and it provides the strongest possible contrast with flowers, gravel, stone, and lawn. It holds a sharp edge and a precise form. European hornbeam (Carpinus betulus) is deciduous — in winter it holds its dry buff leaves rather than dropping them, producing a screen that is structural in summer and semi-transparent in winter. Both read as architecture in the garden.

English yew is an evergreen conifer, slow-growing, extremely long-lived, tolerant of heavy shearing, and one of the most formal hedging plants in European garden tradition. It is appropriate for geometric shapes, walls, and architectural features in traditional New England formal gardens. European hornbeam is a deciduous hardwood that pleaches — trains into flat planes — more readily than beech and holds its shape with one or two shearings per year.

English yew grows slowly — 6 to 8 inches per year once established — which means the form takes years to develop but requires less maintenance than faster-growing plants. It requires one thorough shearing per year, in late summer, to maintain its form. European hornbeam requires one to two shearings and pleaches readily into flat-trained forms.

Boxwood (Buxus) has suffered significant losses in New England over the last two decades from boxwood blight (Calonectria pseudonaviculata) and boxwood leafminer. English yew and European hornbeam are not susceptible to these diseases and are longer-lived, more architecturally forceful, and more historically appropriate for formal New England gardens.

English yew from specialty nurseries — it is not widely stocked because of its slow growth. Prides Corner Farms (Lebanon, CT) carries it. European hornbeam from native plant nurseries and specialty landscape contractors. Both require patience — the formal character takes five to ten years to develop from planting.