“Sustainable” is a word we see everywhere these days and broadly speaking, it means something that sustains itself, be it sources of energy, lumber, or agriculture. But let’s look specifically at sustainable gardening.
What is it? Most sources define sustainable gardening as the creation of a healthy plant-and-soil system that doesn’t need added resources like supplemental watering or potentially toxic inputs like pesticides and herbicides. Here's how that's done.
Use of Organic Methods
- Mulching all uncovered soil for water retention, weed control, and to improve the soil’s structure. Best are shredded hard wood or bark, bark chips, cocoa hulls or leaf mold (composted leaves).
- Composting garden and kitchen waste. If more fertilizer is necessary, using organic sources only (e.g., compost tea or fish- or seaweed-based).
- Choosing pest- and disease-resistant plants.
- For pests, using preventive practices first (like ensuring good air circulation) and taking action only when a plant is endangered. Then using the least invasive or toxic methods first, like horticultural oil for scale and mites, Bt for caterpillars, beetles and mosquitoes, baking soda for black spot and powdery mildew, and SAFER brand soap for many problem insects.
- For pests, using biological and physical barrier controls like bait traps, hard sprays of water to remove aphids, removal by hand, and diatomaceous earth for slugs.
- Minimizing or avoiding the use of pesticides, herbicides, and synthetic fertilizers. If pesticides are used, starting with the least toxic, like insecticidal soap, and steering clear of broad spectrum insecticides.
- Weeding by hand or using a 10 percent vinegar solution.
- In lawns, by using a high mower setting, applying an organic fertilizer in the fall, and applying lime, as needed.
- Always testing the soil before adding amendments like lime.
Water Quality and Conservation
- Using deciduous trees south of your home to create shade, evergreens on the north to stop winter winds.
- Watering smart - directly to the root zone by hand or using soaker or drip irrigation, and preferably in the morning. Avoiding sprinklers. Watering according to plant needs, not a rigid schedule. Watering infrequently but deeply - no fine mists.
- Grouping plants with similar water needs.
- Keeping rain on your property using rain garden techniques and rain barrels. (Rain gardens are depressions in the soil that are planted with water-loving plants.)
- Stabilizing stream banks with the use water-loving plants that reduce soil erosion, like liriope.
- Minimizing bare soil and stabilizing slopes by planting ground covers.
- Replacing or eliminating lawns.
- Minimizing the use of impervious surfaces so rainwater can be filtered before reaching the stormwater system.
- Keeping trash, yard waste, fertilizers and de-icers off paved surfaces.
- Growing drought-tolerant plants.
- Weeding regularly - because weeds compete for water with the plants you want.
- Letting lawns go dormant in the summer.
Let's Not Forget to Sustain the Gardener
What's sometimes neglected in discussions of sustainable gardening is the human element and that's a glaring omission because without the gardener, our gardens here in the East will soon return to forest. But most of us don't have unlimited time to devote to maintaining our gardens, so sustainable gardens are low-maintenance ones. Fortunately, the techniques outlined above go hand in hand with reducing the maintenance burden on the homeowner, especially mulching and choosing easy-to-care-for plants. Further reductions in required maintenance are achieved by relying primarily on trees and shrubs (rather than perennials, annuals, vines), by planting in sweeps and masses (which looks better, too), and using simple curves around lawn or mowing strips.
Sustaining the gardener also means growing what you like and enjoy so that you’ll continue to garden. And finally, it means growing economically, or at least within your budget, again so you’ll keep doing it.
Sustaining Wildlife, Too
Most discussions of sustainable gardening include a word about sustaining the world outside the confines of the garden itself, by providing for local wildlife and avoiding plants that will invade and harm nearby natural areas. So eco-friendly, sustainable gardeners are increasingly choosing plants that sustain insects, birds and other critters we love. Locally native plants, especially trees, are generally best at doing that. We're careful to avoid known invasive plants. And to provide for wildlife, we're willing to incorporate ponds and other water features in our gardens, even if they require a bit of extra maintenance.