Changing Seasons

Figure 7.1 Keukenhof Gardens, Lisse, the Netherlands. visual interest or color can be used to complement a building or other structure. Plants that display seasonal color can be used to add an element of drama or visually highlight the spaces against a building or space within a grouping of buildings and along a road corridor, or at the edges of a park and greenbelt. One example is the use of the brilliant red and orange colors of Japanese maples set within a backdrop of the dark greens of conifer trees or aligned with London plane or oak tree species. The aligning or positioning of plants considering seasonal color changes of leaves and flowers can dramatically change campus and urban spaces or along parkway corridors that draw people to these spaces. They are seasonal events that people look forward to and will travel long distances to see. Consider the annual spring event of flowering of cherry blossoms in Washington, D.C. or the fall color of maple trees in Vermont and Maine. The tree-lined boulevards of Europe are visually enlivened with the drama of seasonal color changes that draw people to these places and make the color display that occurs special times of the year that residents look forward to and of course value and enjoy.

There are some parts of the world that enjoy four distinct seasons (spring, summer, autumn, and winter) while other regions may experience just two (wet and dry). The literature is replete with songs, musings, poems, and stories about or based on the seasons. The seasons—regardless of the number—punctuate the year with changes in climate, color, the arrival and departure of wildlife. The changing seasons serve as a visual timepiece noting when to plant, nurture, and harvest. The changes that vegetation makes throughout the year give physical expression to other seasonal events. As we notice, the swelling of the leaf buds of trees with the coming of spring triggers anticipation of relief from the harshness of winter. Leaf color changes in the fall signal autumn and the time of harvest. The landscapes, unlike the structures of architects and engineers, have a rhythm that infuses feelings of anticipation, relief, abundance, sadness, and joy. Consider how the lyrics in Antonio Vivaldi’s Concerto No. 1 in E Major, The Four Seasons (1720) express the dynamics of changing seasons:

Springtime is upon us. The birds celebrate her return with festive song, and murmuring streams are softly caressed by the breezes. Thunderstorms, those heralds of spring, roar, casting their dark mantle over heaven, Then they die away to silence, and the birds take up their charming songs once more.

Plants through their growth from year to year, from seedling to fully matured plant, are markers of time advancing and in some cases, rebirth. The spaces and places created by landscape architects change physically from wide open to the sky to enclosed, from bleak and uninhabited to a verdant and exuberant density, due to the plants.

Landscape architects know about seasonal changes and the longterm transformations of plant materials and use this knowledge to create their designs. Their designs consist of plant species combinations selected to create spaces or provide experiential or sensual layers supporting the functional requirements of the spaces. While concrete, wood, and steel have their own sensual qualities and may offer the subtle reflective quality of light and other physical changes over time, the dynamic quality of these and other building materials pales in comparison to the daily and seasonal performance and display of plant materials.

Figure 7.2 contains four images representing the four seasons. The photographs are from different locations. They were selected to provide an overview of the seasonal variations a landscape architect has to work with and consider when developing a planting palette for a project. Not all sites and regions offer four distinct seasons. In the tropical regions, the seasons are described as having rainy and dry periods. The seasons one can experience in desert regions are more one-dimensional in that the landscape changes are much more subtle so that seasonal changes are only apparent to those having a practiced eye. The seasons are marked by new and old growth, muted brown-like tones during the extreme dry periods, transforming into highly varied color displays during the wetter months of the year. Also the seasons in desert and arid regions are signalled by the presence of flowers, fruit, in some cases, changes in leaf color or loss. With the loss of leaves, the prominence of a plant’s branching structure emerges.

The planted and natural landscapes of spring present a visual display of new growth of leaves, often much lighter hues of green after the leaves’ buds have unfurled from the bud stage. The same plants gradually darken in the case of broad-leaf and deciduous species going into the summer. Figure 7.2A shows a planting in late spring. The plant leaf colors can be described as bright green and will darken as summer advances. Deciduous species will then take on their fall color with shades of mostly yellow or simply become dry-looking and brown in more northernly regions. Further north, deciduous species display a more varied and intense color, adding red, orange, and magenta to the landscape color palette. Winter is perhaps the more varied in terms of leaf color from region to region depending on the species. Evergreen plants remain a consistent shade of green, depending on the species. Winter display may consist of seed cones remaining for much of the winter while the branches of deciduous plants will be mostly bare, thus emphasizing the branching and limb structure. This description is perhaps overly generalized, so those students with a more curious interest in plants and wishing to expand their palette will more closely study and observe the seasonal variations of plant materials in their regions. The more one understands about seasonal plant colors, the greater the potential to create

A B

C D

Figure 7.2 Seasonal foliage in the landscape: A: Spring; B: Summer; C: Fall; D: Winter.

spectacular plant compositions that take advantage and incorporate seasonal variations.

I remember my first experience of living in a place where seasonal color variation became more than book-learning knowledge for me. A native of coastal Southern California, I had the opportunity of working in Winnipeg, Manitoba (located in a prairie landscape), after graduation from college. We arrived in Winnipeg in the middle of winter. That was quite a jolt in many respects, such as experiencing the extreme cold and the snow-covered landscape. It wasn’t until early spring on my first outing north of the city, where the landscape appeared mostly brown and gray and the snow had disappeared, that I saw the seasonal colors. We were out on a hike along a river floodplain surrounded by a gently rolling upland landscape. What struck me during that introduction to an early spring outing in a northern landscape was the enormously appealing but subtle color patterns of the native landscape. What I saw were bands of color, swaths of low-growing willows and grasses with a backdrop of taller-growing alders, both punctuated by an occasional spruce. The leaf buds of the willows, of varying heights, depending on the species, had swollen, revealing shades of yellow from a butter color to more subtle shades

of the same color. The foreground contained extensive patches of grasses, many with remnants of seeds and dry flowers. The grasses varied in color from all shades of brown, sienna, and strands of burgundy. The upright, mostly gray or dark brown branches of the tall alders in the background had a soft blush of burgundy. The color was produced by the swelling leaf buds. It was on this hike that I experienced my first appreciation of the subtle nature of plant color, form, and structure revealed by a landscape waking up from winter and preparing for spring and the months ahead. The experience, I might add, was intensified when my eyes caught sight of a moose dashing through the willow thicket toward the floodplain where we were heading. I would go so far as to say that I had not realized the extent of and potential application of plants in design until this experience three or four years out from graduating with a degree in landscape architecture. It was late in coming, but I am certainly thankful it happened.

Figure 7.3 contains two photographs taken in the same general location in a public park in Hangzhou, China. The two photographs have been paired to show the color variation of similar plants from summer to late fall. While the photographs were not of the exact location, the effects of the seasonal transformations of a landscape are dramatically evident. As the plant colors change, so too does the visual composition and spatial qualities of the landscape. The landscape spaces A in winter are more open while in the summer they feel more enclosed. The difference between open and enclosed is the result of bare trees and trees in leaf.

In addition to color, plants have other physical and aesthetic qualities. Each plant species has a definite physical form. Common adjectives used to describe plant forms include: pyramid, oval, upright, weeping, tall and upright, broad, spreading, and irregular. Some plants have a sculptural form while others—particularly trees—are known for the structure of their branches which provide visual interest just as their other physical qualities, such as leaf color or overall form can. For example, the ancient Gingko tree has a very sculptural, branching form, not completely evident until the leaves drop in the late fall. The Gingko leaves achieve a radiant display of yellow in contrast to the bright green of spring and summer.

A plant’s texture is another design consideration in selecting plant species. Plant texture takes into consideration the size and shape of the leaves and the light and shadow patterns resulting from the changing phenomenon of sunlight. In addition to texture, plants can be described as having soft qualities or appearing stiff to the eye as well as to touch. Weeping willow is an example of a tree that is known for its soft, malleable appearance. In fact, if you were to run your hands through the leaves,

B

Figure 7.3 West Lake Park, Hangzhou, China. Comparing summer and fall color in the landscape. A was taken in late summer and B was taken in late fall.