Arboretum Bulletin Summer 2019, Volume 81, Issue 2 | Page 9

LEFT: This Japanese black pine—over 100 years old—has been skillfully pruned to maintain its relatively small size and the powerful living architecture of its branching. Over time, it remains a focal point in balance with other plants and garden elements. (Photo by Seattle Parks and Recreation) THIS PAGE TOP: Willows are short-lived trees, and this is the last one remaining of five or six originally planted in the Seattle Japanese Garden. Pruned annually and supported by a wooden post, it will live for a few more years, provid- ing distinctive structure over the seasons and contrasting with the rounded forms of evergreen shrubs. (Photo by Aurora Santiago) BOTTOM: Creating structure and interest throughout the seasons in the Japanese Garden, this weeping Japanese maple has been pruned to emphasize its brilliantly colored spring and autumn foliage and its elegant branching struc- ture, prominently displayed in winter. (Photo by Aurora Santiago) environment, adapt to changing conditions, and­—if possible­—have a long season of interest. Be observant and prepared to respond effectively if your garden is evolving in unanticipated ways. To create a sustainable planting plan, it’s important to consider the types of plants you’ll be using—trees, shrubs, perennials and ground- covers—and how they develop and interact over time. (Even if you don’t intend to plant any trees, there may be neighboring ones that will eventu- ally affect your space!) The trick is to shape the various layers of your garden to create a plant community that will be long-lived. A good place to look for ideas is in a forest setting, where natural plant dynamics play out over long time spans. Learning from Natural Succession Patience and Preparedness In the U.S., we tend to be impatient about our gardens, expecting them to look attractive as soon as they’re installed. Is it any wonder that we overplant them, and they look overgrown in just a few years? Despite our wishes, plants continue to grow, and gardens are processes rather than results. We begin to lose control as soon as we finish planting. Plants grow taller and wider than expected, all too quickly crowding other plants, paths and patios. The sunny garden becomes shady. Some plants are too vigorous and take over, while others die or fail to thrive. Views, open space and plant diversity are lost. As you begin the design process for your garden, consider the longevity and competi- tiveness of the plants you’re selecting and the maintenance and interventions they’ll require. Choose plants that will grow well in your In nature, plants relate to one another in a given space over time through the ecological process of succession. Different waves of colonization, establishment and extinction lead to successive changes in the complexity of the plant commu- nity. Initially, short-lived “pioneer” plants begin growing on bare ground. Often annuals and biennials that germinate from seed and thrive in sunny conditions, these plants grow quickly but are not persistent. Gradually, they are outcom- peted by more slow-growing but longer-lived plants such as herbaceous perennials and grasses. Eventually, many of the perennials are replaced by a more stable “climax” community dominated by woody plants. Each stage facili- tates the next, and a disturbance (such as a tree falling down) can restart the process over again. Though a certain amount of natural succes- sion takes place in most gardens—as the plants Summer 2019 v 7