Green landscaping can perhaps best be described by a holistic system in which all component parts are healthy and contribute to the whole environment. Understanding what the component parts are and how they interact is at the heart of the sustainable movement. Let’s take a look at a balanced, “green” system and discuss a few of the key features in order to understand the practical, social and economic aspects of the new green ideal.
Natural systems are inherently self sustaining where the total needs of plants, insects, animals etc. are met by the available food, water and air of their environment. If the resources don’t exist for a particular species then that species will not exist there either. In the case of plants, the natural soil supplies support, nutrients, air and water to plant roots through a complex web that depends on soil structure, pore space for air and water and micro-organisms, fungi, bacteria, nematodes and others, collectively called soil biota, to digest raw inputs such as dead plant material and leaves.
As managers of constructed sites we typically work with landscapes made up of plants that would not normally exist in that environment given the commonly unhealthy soils, poor drainage, air pollution, reflected light and so on. In response we have gotten very good at supplementing these unnatural systems with synthetic chemicals and fertilizers which prevent the eventual formation of natural systems.
Synthetic fertilizers don’t need to be decomposed by soil biota before a plant can use them and in fact synthetics often contain sulfur, salts and other petroleum distillates that kill or discourage soil biota. They are akin to an intravenous feeding tube used on patients in a hospital in that the food no longer needs to be digested in the stomach to feed the body. When used in perpetuity, the stomach, or soil, ceases to function and a whole host of other problems arise. Soil structure breaks down, reducing pore space. Plant roots, which require both air and water in equal measure, suffocate and rot and the plant dies. Pesticides have a similar effect on soil health and can bring an added detriment to non-target, beneficial organisms as well.
Instead, our efforts need to be focused on transitioning these challenging conditions to a more natural system. This is often very challenging in urban environments since a wholesale renovation of the landscape, required to completely change the soil and plant species, is often too costly or impractical. More practical methods such as mulching with organic products and compost, soil testing and incorporation of natural nutrient sources and compost tea applications to re-inoculate soils with biota require patience and a measure of tolerance for changes in the overall aesthetic.
Social tolerance is not a subject that should be taken lightly. In fact, it’s often the primary reason people begin to think about going green in the first place as it becomes more and more taboo to use synthetic management techniques. But Social norms can also be the fastest way to derail a transition to green management. Traditional images of dark green grass, zero weeds and full, blooming plants define our ideal but they’re not necessarily realistic in an organic landscape, especially one in transition. Your customers and tenants need to be adequately prepared to tolerate some weeds in the landscape, some plant material may suffer and die from insect or disease problems, bloom strength on shrubs may be reduced and turfgrasses will be a lighter shade of green. If they understand this and understand that their previous ideal was not sustainable or healthy you will run into less opposition and frustration during your transition to the new green ideal. Failure to do this may result in pressure to revert to dependency on synthetic pesticides and fertilizers or force you to spend more money on labor and materials to overcome weeds and incorporate more organic nutrient sources.
A qualified horticultural consultant or high quality landscape maintenance contractor can help with the practical, social and economic aspects of transitioning your landscape to green and managing with organic principles.