Advice to Gardeners from a Climate Change Expert
David Wolfe is a Cornell professor of horticulture and a leading authority of the effects of climate change and rising atmospheric carbon dioxide on plants, soils, and ecosystems. His chapter in the book The New American Landscape titled “Gardening Sustainably in a Changing Climate” offers advice on how you can adapt your garden to a changing climate and help reduce greenhouse gas emissions in your garden.
Adapt your garden to climate change
Experiment with new species: If your favorite plants become less able to thrive in new climate conditions, experiment with new species and varieties as plant hardiness zones shift. Dr. Wolfe urges cautious experimentation rather than many radical changes in a single year.
Move up planting and harvesting dates: Projected longer periods of high heat accompanied by low precipitation may require gardeners to shift to slower-growing, drought tolerant plant varieties. Take advantage of an earlier spring and a longer growing season by setting an earlier planting date. This can reduce plants’ exposure to high heat later in the summer.
Manage water: Rain is predicted to fall in more intense events, which can cause plants to have “wet feet” and root disease. Identify where water pools in low spots and reconfigure for better drainage. Use soil amendments to improve drainage during wet periods or to improve water-holding capacity during dry periods.
Protect plants against frost: If higher temperatures come earlier than usual, trees and shrubs may leaf out earlier, making them vulnerable to spring frost. Use freeze-protection mulch or reusable fabrics to cover these plants in the case of frost. Avoid planting on north-facing slopes and low-lying shaded areas that are more subject to frosts.
Be aware of any new invasive threats: Higher temperatures are predicted to bring increased weed, insect, and disease pressure. Keep up with the latest information provided by local Cooperative Extension experts on any new pest threats.
Adapt your garden for native pollinators
Insects are essential to the reproduction of most flowering plants, so supporting a variety of pollinating insects throughout the growing season is beneficial for the success of your garden and surrounding natural landscapes. Climate change impact may cause some plants to shift when they produce flowers, and other plants to grow poorly.
To ensure that your garden provides nectar throughout the pollinator season, follow these tips:
Support pollinators throughout the growing season: Choose a planting palette that blooms throughout the growing seasons, from spring to summer to fall.
Provide “depth in the bench” in your garden: Choose multiple species of plants that perform the same roles at once. By planting multiple species of flowering plants that bloom at the same time, if one plant species in your garden succumbs to environmental impacts or disease, others will still be present to provide nectar and pollen for pollinators in that same flowering window. This is called “functional redundancy.”
Keep your garden flexible: While there are projections for climate change in the future, there are many unknowns. One way to be prepared is to include a mix of flowering plants that have a diverse range of responses to environmental conditions. For example, if the summer is especially warm, only some of your plants may experience stress, while the heat tolerant ones can thrive in the warmer conditions. This is called “response diversity.”
Shrink your garden’s carbon footprint
Try these suggestions to move your garden closer to a carbon-neutral state:
Reduce or replace nitrogen fertilizer: Synthetic nitrogen fertilizers such as urea and ammonium nitrate require a lot of energy to manufacture and transport (for every ton of fertilizer produced, 4 – 6 tons of carbon dioxide is emitted).
As a replacement:
- Set your mower higher than three inches to promote root growth and exploration for more soil for nitrogen
- Leave lawn clippings in place on the lawn, since they hold nitrogen and other nutrients, which are recycled back to the lawn.
- Use organic nitrogen sources, such as manure and compost.
- Avoid applying nitrogen in very early spring.
- For healthy, mature lawns in shaded areas, try using only two applications of supplemental nitrogen per 1,000 square feet.
- If you must use synthetic fertilizer, choose urea over ammonium sulfate or ammonium nitrate, as the production of urea produces less greenhouse gas emissions.
Rethink lawns: Cut down the need for gas-powered mowers and fossil-fuel based fertilizers by replacing high maintenance turf with no-mow grass varieties. Visit the low-mow demonstration lawn at the southeast end of Mundy Wildflower Garden, which displays a variety of grasses ideal for low-mow lawns.
Make your garden a carbon sink: Till your garden less, and instead let plants decompose and become part of the soil’s organic matter naturally. This keeps carbon, and important component of soil health, in the
soil instead of released into the atmosphere..
Plant Strategically:
- Choose native plants, which are adapted to local climate, soil, pests and diseases and require less protection, water and fertilizer. Try your best to place plants in a location that provides the right amount of light, moisture and drainage needed for the plant to thrive without unnecessary inputs.
- Look for the “Veriflora Certified Sustainable Grown” label on plants, which means it meets standards for environmental and social responsibility.
- Avoid buying potting mixes containing synthetic fertilizer. Try making your own by mixing 1/3 compost, 1/3 garden topsoil and 1/3 builder’s sand.
- Planting more trees on your property can help take up carbon dioxide from the atmosphere. Place them to block winter winds and create summer shade to reduce the amount of energy required to heat and cool your home.
Vary your vegetables: Adding diversity to your vegetables by interplanting perennial vegetables and herbs with annual crops requires less fertilizer and maintenance than monoculture beds of annual plants.
Power down and recycle: As an alternative to leaf blowers and weed whackers, mulch well to keep weeds down and rake a little every so often. This composts leaves in small bursts rather than in one big cleanup.
Reuse existing and salvaged materials for garden construction, like bricks and stone, to eliminate the need for manufacturing and transporting new products. Use recycled products whenever you need planter boxes, compost bins, garden hoses, fencing and pots.