We Love A Good Field Trip!
Callander Associates staff recently took advantage of our beautiful Bay Area winter weather to visit Boething Treeland Farms, a wholesale plant nursery located in Portola Valley.
As landscape architects, we had all taken the requisite plant identification and horticulture classes in school, keeping abreast of new plant varieties primarily through in-office research (latest edition of Western Garden book, anybody?). It was a refreshing change to see ‘in the flesh’ many of the plants we have specified. It reinforced some planting design truisms as well as prompted some thoughts regarding the plant selection and specification.
Plants of different species (and varieties) within the same container size will have a different ‘bulk’. One element that can be frustrating as plant specifiers is the range of plant sizes within each species, and the visual impact that larger container sizes oftentimes (but not always) make on the completed landscape. There is a wealth of information on the mature size of plants; what is not so easy is discerning the likely size of a plant in a one gallon container compared to a five gallon container. Plant habits, growth rates, mature sizes, and other factors make it difficult to predict the size of a plant. As designers we try to locate and space plants according to their mature size. Doing so is more sustainable (less hedging required) and budget-friendly (fewer plants). The challenge is in the selection of the right container size for each species that maximizes their ‘Day One’ appearance so that they don’t look too sparse.
Mass planting can provide a striking visual impact. Some styles of planting design and personal preference result in a complex mosaic of multiple plant species, with plants enjoyed at an individual and intimate level. In stark contrast, a forest of Acer palmatum ‘Sango-kaku’ maples, rows of white-barked birch, or masses of Skyrocket and Moonglow juniper provide a striking visual effect, enjoyable from a distance as an almost abstract canvas of color and texture.
Projects rarely have an off season and plants should be chosen accordingly, based on the characteristics they offer throughout the year. We tend to show clients images of plants when they’re flowering and how (beautiful and green) they look at their peak, but that usually only occurs for 2 to 3 weeks out of the year. The middle of winter, when deciduous plants are at their most bare, best showcases the year-round potential of plants. Without any leaves on them, we get a much better idea of other characteristics they have to offer, like their bark, seed pods, branch structure, and form. Two examples of stand-outs were Acer palmatum ‘Sango Kaku’ (Red coral bark maple) and Chionanthus retusus (Chinese Fringe Tree). The Sango Kaku maple had stunning reddish color that stood out from a distance. We normally specify the Chinese Fringe Tree for its flower but its beautiful peeling bark also gives it year-round interest.
Balance deciduous with evergreen plants. Leafless trees have a reduced visual impact due to their more spindly, bare forms. Mixing in evergreen trees helps counteract that. Deciduous grasses can look ragged, especially if they have become overgrown or allowed to brown out. These types of grasses should be well integrated with other plants.
Marie Mai, Associate Landscape Architect