#49 Sustainable Landscape Design: Theory, Planning, Planting, and Care
In my last column we discussed irrigation and water efficiency. The over-riding principle in sustainable landscape design is creating a garden that conserves resources. Water is only one of those resources.
A typical garden requires many inputs: seeds or other plant materials, water, money, labor or time, chemicals, and fertilizers to name a few. Our cultivated landscapes also produce a variety of wastes: plant trimmings and weeds, pollution from run-off, and water lost to evaporation. The concept of sustainable landscaping requires us to consider the input and output of our efforts, and find ways to minimize them both.
Proper design of the garden/landscape begins with analyzing the site for variables such as sun/shade, wind, slope, soil, and available moisture. Once you understand your local gardening environment, you can choose plants that are native or well adapted to those conditions, and that resist pests and disease. This way you will need fewer chemical controls. If you choose to plant non-natives, whether for ornament or food, group plants with like requirements together in the garden.
Whenever possible, choose low water or drought tolerant plants. Select them according to their ultimate size, and position them allowing room to grow; this will decrease the amount of time and labor needed to prune. Think about locating trees, shrubs, and vines to shade the house and provide temperature control. When possible, considering layering them as is common in nature. This means you would start with large trees, then understory trees, shrubs, and finally perennials, bulbs, and groundcovers. Select plants with edible berries and seeds that will provide food for birds and other wildlife in the garden.
Prepare the soil before planting. Increasing the humus content by the addition of compost will improve most soils. Again, use materials that are available nearby, like city recycled compost, or your own compost, once the garden is established. If you suspect the soils are depleted from previous gardening practices, have the soil tested before amending. Visit one of these two regional soil testing facilities for more information on price and procedures. www.txplant-soillab.com or www.soiltesting.tamu.edu If supplementation is needed, you can purchase organic soil amendments at Kimas Nursery on Hwy 71 and Harmon Road, or by ordering them through Smith Supply on Loop 230 and Hwy 71 in Smithville.
Cover all planted areas with a mulch. In our area, cedar or pine bark and pine straw are the most widely available and least costly. This practice will help to prevent both evaporation and erosion, and also weed competition with the desirable plantings. Mulch also adds nutrients to the soil as it decomposes.
Minimize lawn areas. Where lawn is a must for sports or child’s play, mow it high (2-3 inches) and water infrequently (twice a week in summer) and deeply (at least 1” per watering session). Use environmentally friendly fertilizers such as corn gluten meal or other organics, to avoid run-off of toxic chemicals such as nitrates and herbicides. Use a mulching lawn mower and allow clippings to remain on the grass, or compost them if you choose to bag them.
Finally, consider organizing the garden to provide restful areas for contemplation. The use of sustainable landscape design practices should result in a lower maintenance garden and the time to stop and smell whatever fragrant plants you locate there.