Refugia Gardening

Principle #1: Using climate projections, enrich biodiversity in outdoor living spaces by converting lawn spaces to refugia gardens.

Most refugia gardens will consist of trees, shrubs, and perennials. Because trees are long-lived species, pay special attention to their vulnerability and adaptability to climate change. Refugia are suitable for vulnerable species, but you will likely want to also consider trees (native to your region) with greater resilience and/or adaptability. Species that also provide habitat, food, and nesting sites for native insects and birds should be a priority. We have included tools and tips below to help you start researching priorities for your refugia.

Helpful Climate Tools for Gardeners

• This short Washington Post article offers some great visuals regarding the changing climate and hardiness zone where you live and the suitability of different tree species in light of these changes.
• The Climate Change Response Framework is an invaluable website maintained by climate adaptation specialists for researching tree vulnerabilities and resilience to climate change. We recommend the guides accessible via their Resource Finder and Focus Areas menu. Do include some native species that are more vulnerable to climate change. After all, refugia are supposed to be place of refuge. But don’t be afraid to include some ecologically beneficial trees that are native to the zones that are suited to your area’s future climate projection. It may help to think of them as your “climate natives.”
• USDA’s Climate Pressures in the 21^st Century provides interactive mapping for plant hardiness, growing degree days, and heat stress zones. Using a slider bar, you can quickly compare your 1980-2009 climate with the projection for 2070-2099.
• Climate.gov’s Climate Explorer provides interactive mapping for precipitation projections in your city or county.  Using their maps and/or graphs, you can compare low- and high-emissions scenarios for present and end-of-the century projections. You can also learn about projections for extreme weather events, high tide flooding, and climate action options.
• National Wildlife Federation’s Gardener’s Guide to Global Warming offers practical suggestions for reducing your garden’s environmental impacts, improving water use efficiency, composting, and aiding your garden’s adaptions to climate stress. The guide also suggests climate action steps and advocacy options.

What Kind of Garden?

• This can be any option ranging from wildlife garden (focused on the needs of other species) to vegetable/ornamental garden (focused on human needs). A blend of these will likely be ideal for most gardeners.
• To promote wild biodiversity (which is key to the refugia concept) provide nesting and food plants for native insects and birds. Aim for flowering plant species that bloom at different times throughout the growing season to ensure a supply of nectar that coincides with the arrival and breeding of different pollinators. Climate change is likely to affect phenology (the timing of these events), and so planting various nectar-rich species helps to ensure thriving populations of pollinators.
• Focus on layers of perennials/annuals (ground), shrubs (undergrowth), and trees (canopy). This mimics the structure of ecological communities, ensuring multiple levels for species interactions to occur. Such interactions enable ecosystems to be more resilient when facing multiple stresses during climate change.
• Add in some edible/medicinal/ornamental plants that you enjoy and/or plants with special meaning/stories that connect to your cultural heritage, personal experiences, or local history.

 

Easy Eco-Friendly Lawn Removal

Managing Soil Health, Weeds, Diseases, and Pests in Your Garden

• Minimize soil disturbance. If weeds can be controlled by cutting, do that instead of pulling out roots. Use organic mulches (fallen leaves, wood chips) and dense planting to minimize bare ground.
• Promote soil health biotically. Monitor your soil’s organic content (readily visible as dark coloration), which is an indicator of its fertility and sequestration of carbon. Use cover crops, companion plants, organic mulches such as leaf litter, and/or compost to encourage growth of soil microbes and to enhance nutrient availability to plants. Consider periodic soil pH and nutrient testing, especially if you notice plant symptoms that might indicate malnutrition. The agricultural extension office in your county offer services for diagnosing such problems.
• Take a holistic approach to plant health. Avoid using chemical fertilizers and pesticides to try to solve a problem quickly. Chemical fertilizers actually can encourage the growth invasive weedy species. Learn to accept some caterpillar damage on plants as a sign of ecosystem health. Improving soil health will help the plant’s innate defensive mechanisms. When you do notice a new species of plant-eating insect, try to identify and learn about it. Monitor for invasive insects that may cause ecological problems and take appropriate action as recommended by experts. Also be on the lookout for spotting and wilting on plants, which can be signs of microbial diseases. Consult with experts on how to prune and discard diseased plant tissues. 
• Use fences and organic repellents to deter deer, rabbits, etc. Excessive browsing by herbivores reduces plant health and growth. We have found that Plantskydd is an effective repellant that does not require excessive reapplication (once every 2-4 weeks on new growth). It is a bloodmeal-based product that works presumably because herbivores associate the smell of blood with predator activity.

More Refugia Gardening Principles and Practices
1-Diversifying for the future
*Why not natives only?
2-Focusing on ecological functions
3-Enhancing natural landscapes
4-Co-creating with nature
5-Cultivating relational caring