Climate Smart Gardening: How To Reduce Emissions, Capture Carbon And Better Serve Wildlife

As eco-conscious homeowners consider how to curtail their personal contributions to climate change, they tend to look indoors, searching for ways to increase energy efficiency. But there are so many moves they can make outdoors that will not only reduce their carbon footprint, but also sequester carbon and contribute to biodiversity.

Anyone who is a steward of land, from the largest estate to the smallest yard, can add carbon-capturing native plants that provide food and habitat for the insects, birds, and other wildlife that are struggling in the face of habitat loss and climate change. It’s a strategy that conserves water and doesn’t require fertilizer, plus it’s less labor intensive and less costly than maintaining a lawn.

Becoming a climate-smart gardener requires more than just “going organic.” Organic gardens and lawns are free of synthetic pesticides and chemical fertilizers, but they can still have quite the carbon footprint.

Flame-weeding is an approved practice in certified-organic agriculture, but burning propane is not climate smart. Applying bags of compost is organic-approved, but using products that were shipped on trucks for hundreds of miles in plastic bags is not climate smart. Peat moss is an organic seed starting medium and soil amendment, but it’s harvested from peat bogs, releasing untold amounts of long-sequestered carbon into the atmosphere.

In terms of protecting wildlife, organic gardening is certainly superior to conventional gardening in numerous ways, though it comes up short in combating climate change. Organic gardeners who want to step up their game can follow the practices and principals of regenerative agriculture and permaculture to achieve the goals of climate-smart gardening: minimizing emissions of carbon dioxide and other greenhouse gases while actively sequestering carbon in plants and soil.

To increase biodiversity and support wildlife, add to the mix ecological horticulture, which calls on gardeners to work in concert with nature — rather than trying to outsmart or overcome it — to have beautiful outdoor spaces that don’t require chemical intervention to maintain.

Planting flowers — any flowers — is often thought to do the trick to support pollinators. However, while non-native flowers can be helpful to generalist insects, they aren’t of use to the specialists. What’s worse is that non-native plants can also be aggressive, out-competing and replacing native plants.

Native plants co-evolved with native bees, butterflies and other vital insects. For specialist insects, if specific native plants are not available to them, they can’t sustain their populations. They need the plants that they developed evolutionary relationships with. Other pollen and nectar sources and other leaves simply can’t replace those of their evolutionary partners.

Destruction of wild habitat to make way for development has made native plants harder to find for native insects. Those insects provide important ecological services — pollination, pest control and more — but they are declining in population. As “Bringing Nature Home” author and entomologist Douglas Tallamy points out, birds’ numbers are likewise declining because those missing insects were the source of food for rearing their young.

Edwina von Gal of the East Hampton-based Perfect Earth Project started an initiative called Two Thirds for the Birds based on Tallamy’s research, which found that birds need 70 percent of the plants in their range to be natives in order to support their populations. Two Thirds for the Birds challenges gardeners to plant two native plants for every non-native plant that they put in the ground and to remove invasive plants that are crowding out natives.

Gardeners can identify the best native plants for their area by using the National Wildlife Federation’s Native Plant Finder tool, a free resource offered online. It takes the guesswork out of determining which flowers, grasses, shrubs and trees are natives versus imports, and it also reveals the butterfly and moth species that rely on those plants for sustenance in either their larval or adult stage.

Americans, in general, love their lawns, but turfgrasses are falling out of favor. There is a growing movement among concerned homeowners to reduce the amount of space dedicated to turfgrasses and dedicate it instead to meadow plants, shrubs, and trees.

Maintaining turf is very demanding in terms of water, time and money. Conventional lawn care includes more pesticide applications per acre than agriculture, and fossil fuel-powered mowers and blowers contribute to climate change. Switching from gas-powered equipment to battery power will significantly reduce emissions — but those batteries still have to be charged somehow. The climate-smart solution is to remove the need for mowing and blowing altogether.

Shrinking a lawn by replacing turf with dense plantings of native grasses and flowers means less work for gardeners because native plants evolved to thrive in their original ranges. Native plants never need fertilizer if they are planted in the appropriate type of soil and, after getting established in the first year or two after planting, they never need to be watered again. Long Island’s native plants are accustomed to the drought, disease and pest stresses in the region, so barring any invasive pest insects and imported pathogens, they don’t require human intervention to thrive.

When a landscape is no longer addicted to fertilizer, the emissions cost of maintaining it is dramatically reduced. Just last year, a study found that 2.4 percent of global greenhouse gas emissions are due to the production, transportation and use of synthetic nitrogen fertilizer, which is responsible for both carbon dioxide and nitrous oxide emissions. Refraining from using fertilizer also curtails pollution of the East End’s waterways, which are experiencing algae blooms that are both more frequent and more toxic due in no small part to fertilizer runoff and climate change.

Native plants will sequester carbon both in their own biomass and in the soil they grow in.

For the turf that remains, grass clippings should always be mulched right into a lawn, where their nutrients and water will be returned to the soil. The clippings also help to regulate the soil temperature, retain moisture and suppress the growth of weeds. When clippings are bagged up and removed or blown away by leaf blowers, the grass misses out on all those benefits — and the atmosphere accumulates more carbon.

When organic matter decomposes in a landfill, it generally does so in the absence of oxygen. The anaerobic conditions produce methane, a greenhouse gas that traps heat at 25 times the rate of carbon dioxide.

South Fork towns offer yard waste composting facilities, which are preferable to landfills in terms of climate-smart practices, but transporting leaves and other vegetative debris has an emissions cost. On-site composting at every home does away with any unnecessary emissions, and it provides gardeners with a free soil amendment that improves a garden bed’s fertility, feeds its beneficial soil microbes and helps it hold just the right amount of moisture to keep plants happy between waterings.

Leaving leaves to decompose where they fall does wonders for a number of insect species and improves the soil below, but at a home, there will always be leaves that fall where they can’t stay. Rather than bagging leaves to be hauled away, they should be piled up on site. In less than a year, they will become what’s known as “leaf mold,” which are leaves in a semi-decomposed state. Leaf mold can be used as a mulch or soil amendment, or let it be for a few more months to become finished compost: crumbly, brown-black, earthy-smelling organic matter with no discernible pieces of leaves remaining.

Getting to finished compost faster can be achieved by “hot composting.” No heat source is necessary. Instead, when the carbon-rich sources and nitrogen-rich sources in a compost pile are in the right balance, microbial activity creates its own heat. Leaves, wood, cardboard and paper are a few popular carbon sources, while fresh grass clippings, vegetable scraps from the kitchen and coffee grounds are popular nitrogen sources. Adding nitrogen sources such as these to a leaf pile will accelerate decomposition while also keeping the organic waste out of a landfill.