Plants of the New College Avenue Border

Spring is time for planting and our volunteers and interns have been busy installing a new planting along College Avenue. As a result of the completion of the Wister Education Center and Greenhouse, the garden bed along College Ave. needed a face-lift.

Originally this bed served as a screen for the parking lot and the dilapidated original Wister Greenhouse. The intent of the new planting is to create a more dramatic offset to the new Wister Center. A series of shrubs has been planted to reach about five feet high and screen the cars in the parking lot but allow a view of the new Wister Center. Repeating masses of evergreen, dry-tolerant perennials create an interesting but subtle ground layer.

Heptacodium miconides provides shade over the plantings along College Ave. photo credit: R. Robert

The canopy consists of several trees from the original planting, Prunus ‘Okame’, Heptacodium miconioides, and Ilex opaca.  Curator, Andrew Bunting’s new design uses Mahonia x media ‘Winter Sun’ and Ilex glabra ‘Shamrock’ as the screening shrub layer.

M. ‘Winter Sun’ was selected for its more compact growth habit and increased fragrance. Like all mahonias, M. ‘Winter Sun’ will provide multi-seasonal interest with sprays of yellow flowers in late fall and early winter developing into black berries for the birds in later summer and autumn. The evergreen foliage will create a screen throughout the year.

Ilex glabra ‘Shamrock’ was selected as a compact cultivar. This evergreen shrub is slow growing with an upright rounded habit. These features also create a screen throughout the year. The small leaves of I. ‘Shamrock’ make a contrast to the large dramatic foliage of M. ‘Winter Sun’.

Heuchera villosa 'Autumn Bride' photo credit: R. Robert

Planted in repeating masses as the understory are Heuchera villosa ‘Autumn Bride’, Meehania cordata, Carex flacca ‘ Blue Zinger’, Carex platyphylla, and Polystichum acrostichoides. Heuchera villosa ‘Autumn Bride’ is an easy-care shade-tolerant plant with chartreuse foliage. In addition to the foliage contrast it provides in the garden, H. villosa ‘Autumn Bride’ blooms with long stalks of pure white typical Heuchera flowers.

Carex flacca 'Blue Zinger' photo credit: R. Robert

For spring interest in the border, the trailing stems of Meehania cordata create a carpet of green coated with blue flowers in late April to May. Carex flacca ‘Blue Zinger’ and Carex platyphylla both provide an evergreen, shade-tolerant groundcover. C. ‘Blue Zinger’ has a light blue tint on the sedge’s foliage, while C. platyphylla has a thicker, powder-blue leaf adding texture and subtle plays of color.

Polystichum acrostichoides. photo credit: R. Robert

Polystichum acrostichoides, Christmas fern, was selected as an evergreen fern to add to the understory. The fountain-like clumps of Christmas fern add a neat habit and dimension to the masses of perennials in this planting.