Learning from Nature, Gathering Data – Citizen Science in the Garden

On the day the International Union for the Conservation of Nature announced that migratory monarch butterflies had been added to the IUCN Red List of Threatened Species, I found a monarch caterpillar chewing on milkweed in my garden. The four square foot patch of butterfly weed (Asclepias tuberosa) that lured the parent butterfly to lay eggs is a scrappy transplant situated amidst a stretch of liriope. Because of the stress of digging up the milkweed’s taproot, the plant was not a particularly vigorous bloomer in its new location, which was meant as a placeholder as the garden was redesigned.

Despite these less than optimal conditions, I counted seven monarch caterpillars on the milkweed a few weeks after the IUCN announcement and, a bit later, discovered two monarch chrysalises hanging from the siding on my house. By chance, I was able to observe one monarch as it completed its metamorphosis, freeing itself from the chrysalis and drying its wings before wafting away.

An internationally recognized endangered species was reproducing in my suburban garden, on a plant temporarily stuck in the ground. Could restoring the environment really be this easy?

Well, no, but as anyone who has planted milkweed understands, such small acts can be both symbolic and practical: symbolic in that they represent potential–imagine the patch of milkweed multiplied–and practical in that they do contribute to restoration efforts, if only by a few caterpillars.

Equally important is what can be learned from this process. When you plant milkweed, the entire lifecycle of the monarch butterfly becomes visible. You realize through this experience how the destruction of monarch habitat–the removal of the milkweed host from the environment–reduces monarch populations, knowledge that makes it easier to support environmental policies favoring monarchs.

Nature provides countless opportunities to learn from small acts. A similar education occurs after planting asters, when bees and beetles, flies, moths, and butterflies land on the flowers, feeding at a time of year–late summer and autumn–when nectar and pollen are not plentiful. It becomes clear that garden design should include an element beyond aesthetics and the mantra of “right plant, right place”: right nectar, pollen, and host plants to attract and sustain pollinators and other beneficial insects year-round.

Possible Condylostylus Fly – A Mite and Aphid Predator

Watching these insects in real time leaves an impression more powerful than any articles I’ve read or webinars I’ve viewed about gardening for wildlife. “Let Nature be your teacher,” the poet William Wordsworth wrote two centuries ago, advice that is even more compelling in an era of climate change and rapid species extinction. I am awestruck as I observe these mostly tiny creatures access nectar and gather pollen, all in their own way, and marvel every time metamorphosis from egg to larva to pupa to monarch butterfly succeeds. I want to learn more. And it’s easy, once you see it, to become lost in the beauty of these creatures, the jewel-like and shimmering colors and abstract patterning of thoraxes and wings.

But it’s more than beauty that calls out for observation, it’s the behavior of individual pollinator species. The bees that visit the penstemon in spring are different from the bees that visit the agastache in summer. The tiger swallowtails that land on the verbena do not appear as interested in the nearby ruellia. How pollinators act, which plants attract them (and when those plants bloom), whether they are infrequent or frequent visitors, the time of year they arrive — these are all points of data. Such data, collected and reported by individual gardeners through citizen science projects such as Budburst and Bumble Bee Watch, and analyzed by project scientists, can help tell the story of pollinator species and how they are faring.

Planting for pollinators is a conscious act that brings beauty and life to the garden. Taking the additional step of reporting garden observations to the citizen science community lends support to conservation efforts, increasing the likelihood that pollinators, and the plants that depend on them, will survive. Nature teaches, and we watch and listen and share what we learn, giving back to keep nature going.


Notes

  1. “Migratory monarch butterfly now Endangered – IUCN Red List”, IUCN Press Release, July 21, 2022. Accessed October 28, 2022. https://www.iucn.org/press-release/202207/migratory-monarch-butterfly-now-endangered-iucn-red-list
  2. Danaus plexippus ssp. plexippus (Migratory Monarch Butterfly). IUCN Red List. Accessed October 28, 2022. https://www.iucnredlist.org/species/194052138/200522253
  3. Lyrical Ballads, with Other Poems, 1800, Volume 1 by William Wordsworth. See the poem “The Tables Turned; An Evening Scene, on the same Subject.” Project Gutenberg. Accessed November 2, 2022. https://www.gutenberg.org/ebooks/8905
  4. Butterfly Life Cycle. The Academy of Natural Sciences of Drexel University. Accessed October 28, 2022. https://ansp.org/exhibits/online-exhibits/butterflies/lifecycle/

If you’d like to learn more about citizen science or find a project for your garden . . .

Budburst. Chicago Botanic Garden. Accessed November 1, 2022. https://budburst.org/

Bumble Bee Watch. The Xerces Society, the University of Ottawa, Wildlife Preservation Canada, BeeSpotter, The Natural History Museum, London, and the Montreal Insectarium. Accessed November 1, 2022. https://www.bumblebeewatch.org/

Citizen Science Association. Accessed October 28, 2022. https://citizenscience.org/

CitizenScience.gov. Accessed October 28, 2022. https://www.citizenscience.gov/#

Community Science. Xerces Society for Invertebrate Conservation. Accessed October 28, 2022. https://xerces.org/community-science

JourneyNorth. Arboretum, University of Wisconsin-Madison. Accessed November 3, 2022. https://journeynorth.org/

3,500 Square Feet, 25 Species, No Feeders – The Birds in My Backyard

When I first began gardening, setting up a few feeders seemed the best strategy for attracting birds to my backyard. Filled mostly with black oil sunflower and nyjer seeds, the feeders quickly became crowded, and the constant chatter of visiting birds brought life to the garden. The feeders were a success, and I felt good about supporting local and migratory bird species.

Several years later, my perspective has changed, not from an epiphany but through paying attention, gradually, to what I have been hearing about gardens as habitat for wildlife. I discovered the ecological gardening literature, began attending lectures on pollinator-plant relationships, and started to experiment with native plants. The logic of the ecosystem took hold. When you understand that beneficial specialist insect species can survive only if they have access to the plants with which they’ve evolved and that birds rely more on the caterpillars sustained by these plants than on seeds to feed their young, it changes your notion of the garden.

From this ecological viewpoint, the intention with which a garden is designed expands to include plant selections that not only look good but also supply birds with food and shelter. Feeders become less critical and more supplementary when plants are feeding the birds. As I chose more caterpillar-supporting and berry- and seed-producing trees, shrubs, and perennials for the garden, and as those plants became established, I decided to take down the feeders to see what would happen.

This feeder experiment was not a scientific study. I did not have baseline data for bird behavior in the old garden, to use as a comparison with bird behavior in the new, feeder-less garden. Nor did I regularly take notes of what I observed. But I did observe, informally, and what I saw became an argument for continuing this approach.

Gray Catbird and Sweetbay Magnolia fruit
Gray Catbird and Sweetbay Magnolia Fruit

Twenty-five bird species visited my 3,500 square feet of backyard garden over a single year. Tiny ruby-crowned kinglets appeared, flicking their wings as they searched for insects along the branches of the river birch, moving so quickly I could barely keep my binoculars focused. American goldfinches discovered the white echinacea, swaying on bending stalks as they pulled seeds from the flower heads. Ruby-throated hummingbirds buzzed from cardinal flower to cardinal flower, sipping nectar. Catbirds, cardinals, blue jays, and mockingbirds stopped by regularly to check the fruit on the sweetbay magnolia, extracting scarlet seeds as they ripened. House finches foraged on lyreleaf sage, holding on as the thin flower stems curved to the ground.

And one day a pair of brown thrashers took a slow turn around the garden, from one end to the other, flipping over bits of soil and leaf litter and poking around the roots of the perennials and shrubs. Were they drawn by the plants or the insects nurtured by the plants, or did they just happen to be in the neighborhood? I don’t know, but I hope the plants played a role.

All the plants that brought birds to the garden were ones I chose for their value to wildlife and as replacements for less beneficial euonymus, yew, English ivy, crape myrtle, a rose of Sharon, and a lot of bare ground covered in mulch. I also planted a willow oak, knowing that oaks in particular are hosts for hundreds of species of caterpillars. I can’t say I’ve seen the results of this choice yet, with chickadees, for example, flocking to the oak to find caterpillars for their young, but I’m keeping an eye on developments.

The feeders remain in the shed, and I continue to research wildlife-supporting plants to add to the garden. I don’t know how many birds a garden this size typically attracts and whether 25 is more or less than what might be expected, but this number is now a data point to use for assessing the garden’s evolution as a habitat for birds. The feeders may go up again, but for now I’d like to keep the bird-plant interaction experiment going. The future goal? Fifty species might be a stretch, but why not?


For details . . .

See The Birds in My Backyard spreadsheet for a description of what I observed.


Leave the Leaves, But Why? Look to the Research

Leave the leaves! It’s an exhortation to gardeners to stop raking and blowing tree, shrub, and perennial leaves that drop in autumn, keeping the leaves in the garden as a natural mulch. This approach stands in contrast to the more common practice of bringing in shredded hardwood or another variety of mulch every spring, after scraping the garden clean in preparation.

If you think about how a forest functions, leaving the leaves makes sense. The annual forest leaf drop resupplies existing soil with nutrients, creates new soil, and serves as habitat for overwintering insects. But most residential gardens aren’t the size or complexity of forests. Will leaving the leaves in these spaces really help?

Looking over the current gardening and conservation literature, the answer appears to be yes. Fallen leaves insulate the soil, helping burrowing insects withstand potentially lethal fluctuating temperatures, and the leaves provide winter mulch for perennials susceptible to frost heave and other effects of cold weather. But the leaves must be left whole rather than shredded, to protect insect eggs laid on leaf surfaces and chrysalises formed from or hidden among the leaves.

What’s exciting about these recommendations is that they’re being studied as research questions, at places such as the University of Maryland’s Burghardt Lab. Descriptions of the studies and findings to date are summarized in blog posts (“My Year Playing With Litter” and “Suburban Lawn Study Launched”) and videos (“Preliminary Results: Initial findings from insect collection”).

The final results should provide evidence to help answer questions a gardener may have about leaving the leaves, questions such as:

  • Which species of insects, and in particular butterflies, moths, and bees, are reduced when leaves are removed?
  • Must the leaves be left in place for a full 12 months (essentially, forever)? If leaves can be removed, when is the optimal time?
  • Are there any negative effects of moving leaves around a property, such as distributing leaves across garden beds instead of leaving them where they fall and clearing leaves away from the crowns of perennials?
  • If leaves are removed from a garden after winter and mulch is applied, are there any benefits to applying commercial leaf litter/leaf mold rather than shredded hardwood mulch?

Traditional annual garden leaf cleanup has been described as a kind of unintentional bait and switch, where pollinators and other insects are encouraged to spend most of the year thriving on a garden’s nectar and pollen, only to be swept away in the fall. Generations and life cycles are interrupted. The garden’s usefulness as an ecosystem is reduced. Research on leaving the leaves has the potential to change this longstanding gardening practice.


If you’d like to read more . . .

Black, Scott Hoffman. “Leave The Leaves To Benefit Wildlife.” 12 November 2020. Xerces Blog, The Xerces Society for Invertebrate Conservation. Accessed June 26, 2022. https://xerces.org/blog/leave-leaves-to-benefit-wildlife

Center for Pollinator Research. Department of Entomology, PennState College of Agricultural Sciences. Accessed June 26, 2022. https://ento.psu.edu/research/centers/pollinators

Dawson, Cathy. “Delay Garden Cleanup to Benefit Overwintering Insects.” August 17, 2020. PennState Extension. Accessed June 26, 2022. https://extension.psu.edu/delay-garden-cleanup-to-benefit-overwintering-insects

Jordan, Sarah Foltz, Jennifer Hopwood, and Sara Morris. “Nesting & Overwintering Habitat for Pollinators & Other Beneficial Insects.” 2020. The Xerces Society for Invertebrate Conservation. Accessed June 26, 2022. https://xerces.org/publications/fact-sheets/nesting-overwintering-habitat

Roach, Margaret. “A Smarter Fall Cleanup.” September 30, 2020. The New York Times. Accessed June 26, 2022. https://www.nytimes.com/2020/09/30/realestate/fall-garden-cleanup.html

Truss-Williams, Anaya. “Want to help the environment? Some local residents suggest keeping leaves on yards.” October 28, 2021. The Diamondback. Accessed June 26, 2022. https://dbknews.com/2021/10/28/prince-georges-county-environment-leaves-yards/


Designing a Perennial Garden Bed

Where do I start? It’s a question heard repeatedly in gardening webinars. Or maybe the question really is, how? When you’re contemplating a piece of ground you’d like to convert to a gardened space, how do you figure out which plants to select from the many thousands available? And how do you arrange those plants to create a design?

For practice, start with a manageable space. Create a design for a small garden bed, and you might be able to use it as a source of ideas for the rest of the landscape. Or, if conditions are appropriate, you can tie the larger design together by repeating the small bed’s grouping of plants in other parts of the garden.

As an example, imagine a 6′ by 10′ space, designated for perennials.

To determine the range of plants suitable for this plot, assess the cultural conditions by asking questions about the environment. Four basic questions are:

  • How much sun does the plot receive?
  • After rain or watering, does the soil dry out quickly and remain dry, drain easily but retain some moisture, or drain slowly and rarely dry out?
  • In which plant hardiness zone is the plot located? The hardiness zone indicates the average annual coldest temperature for a location and is used to identify plants that will survive.
  • Where on the property is the plot located? Is it a foundation planting (next to a building), an island bed, or part of a perimeter planting?

The next questions are about the characteristics for this particular planting:

  • What is the preferred bloom period for the flowering plants in the plot?
  • What are the color preferences for the blooms?
  • Will the mix of plants include:
    • Ornamental grasses?
    • Plants that attract bees, butterflies, moths, and other pollinators?
    • Native plants, and if so, are cultivars acceptable? Cultivars are plants with features deliberately selected to change or enhance what is found in the wild, such as flower color.

With these questions answered, consider shapes and heights, which might be:

  • Tall, medium, short
  • Upright, mounded, trailing
  • Wild, semi-wild, contained.

Returning to the example, our 6′ by 10′ plot:

– Is in full sun
– Has good drainage
– Is located in hardiness zone 7A, and
– Is a foundation planting in front of the house.

For plants, we would prefer:

– Perennials that bloom from spring through late fall (May into November, if possible)
– A mix of red and yellow blooms, perhaps with purple as a contrast
– At least one type of ornamental grass
– Pollinator-friendly selections
– At least half of the plot to be filled with native cultivars or other native selections, and
– A design that combines control with a bit of wildness.

Having decided on characteristics, we can begin to imagine plant shapes and arrangement. A simple and traditional design for a foundation planting, which can be viewed only from the front or side, is to start with a tall plant in back, a medium height plant in the middle, and shorter plants in front.

The tall plant will be closest to the foundation and probably will have the most contained shape, with its verticality emphasized.

A mounded middle plant will provide contrast with the tall plant. Or if not mounded, try a shorter upright plant with stems that bend out to the sides, vase-like.

In the front could be a mix of heights and shapes, with lower mounding plants, trailing plants, and short upright plants.

Plant identification—the research phase of this process—comes next, using plant databases to match cultural conditions with plant characteristics.

For this perennial bed exercise, four databases come to mind as potentially useful. The Missouri Botanical Garden Plant Finder covers native and nonnative plants and provides search criteria including plant type, zone, sun, water, color, and bloom time. Another source with numerous search criteria is the University of Connecticut Plant Database. The Mt. Cuba Center Trial Garden publishes detailed evaluations of native plants and their cultivars, and the Native Plant Database maintained by the Lady Bird Johnson Wildflower Center allows filtering by states and a variety of plant characteristics.

It’s tempting to jump into searching, especially with such interesting resources, but a little preparation can prevent the process from becoming overwhelming. My preference is to use a checklist to record answers to the questions about cultural conditions and characteristics.

To keep track of plants identified, I use a spreadsheet that includes the criteria from the checklist plus additional features such as the height of each species and the recommended spacing for planting.


With the plants identified, there’s enough information to create a layout for the space, or multiple layouts showing different configurations. You can follow the arrangement described above (starting in the back of the plot and moving forward with tall, mounded, and short upright plants) or the plants identified may suggest their own arrangement:

  • Use graph paper, drawing paper, or design software to sketch the 6’ by 10’ perennial bed footprint, noting the scale (1/2” equals 1’, for example)
  • Choose a method to fit the design pieces—the plants—together:
    • Sketch possible groupings, in detail if you can or using circles, ovals, and other simple shapes to represent clusters of plants
    • Place stakes in the plot to represent the plants and photograph the layout
    • Assemble a digital illustration, with photos of the plants superimposed on the footprint (see below)
  • Determine the number of plants for each part of the design, using the spacing information already recorded or planting calculators available online.

The design is ready for implementation and, most likely, modification. Plants carefully identified may not be available, requiring substitutes to be found; growing conditions may not be as suitable as expected, causing plants to fail; and the design that looked great on paper may evolve in a year or two to a jumble that requires cutting back and rethinking.

It is this evolution that is one of the more challenging but also rewarding aspects of planting design. Time is a design element, and as plants grow, the design changes. Understanding how plants interact and affect a design over the seasons is essential knowledge, gained from experimentation and experience, over time.

And if over time the design works, you can duplicate it elsewhere in the garden or use a rearranged version — imagine Calamagrostis surrounded by rings of Helenium, Coreopsis, and Geranium in an island bed, for example, or Asters and Coreopsis combined to cover the sunny sloping edge of a larger garden bed.

Where to start? Start small and build.


Reconsidering Peat in the Garden

Check the list of ingredients on bags of potting soil and soil conditioners at your local garden center and you’ll probably find peat among the entries. The purpose of this dry, lightweight potting medium is to improve drainage, providing plant roots with access to water, oxygen, and the nutrients required for growth. Peat doesn’t supply the nutrients but facilitates their absorption by changing the structure of the soil.

When added to dense and saturated clay soils, peat breaks the soil apart, creating space for air to infiltrate. These air pockets allow plant roots to absorb oxygen, an element essential for plant health. If a plant’s roots can’t access oxygen, the plant may die. Plants in this condition often are described as having suffocated or drowned from wet, airless soil.

When added to sandy soils, peat slows drainage, enabling plants to absorb nutrients that usually wash away before they can be used. Sand particles are large but have less overall surface area than clay particles, which reduces the amount of water the sand can retain. Peat’s ability to expand when wet adds needed texture and surface area to these loose soils.

Plants thrive in response to these changes in soil structure, which is why peat has been a popular gardening and horticultural product since it began to be marketed in the mid-1900s. But this use of peat comes at a high cost. To extract peat, wetland areas known as peatlands are drained, and the mined peat is dried over time. These processes release carbon dioxide, one of the gases responsible for a warming climate. According to the International Union for the Conservation of Nature’s IUCN Issues Brief: Peatlands and climate change, drained and otherwise damaged peatlands are responsible for 5% of annual worldwide emissions of greenhouse gases. Damaged peatlands cover 0.3% of the Earth’s land surface, while total peatlands, intact and disturbed, make up 3% of the planet’s landmass. Imagine the multiplier effect on emissions if peatland drainage expands.

Peat is a resource that takes millennia to develop and only in the right conditions. Sphagnum mosses, grasses, sundews, sedges and other peatland plants must be submerged in water and left undisturbed after dying. Decomposition by microbes occurs, but the limited oxygen in the wetland conditions inhibits microbial respiration, which slows the breakdown process. Over time, as plants continue to die, more plant material accumulates than decays. Carbon removed from the atmosphere during a plant’s life, through photosynthesis, is preserved in the layers of semi-decayed plant material, which in some peatlands can be 20 feet deep. As long as peatlands are not mined or otherwise damaged, this carbon is locked away, in such quantities that peatlands store more carbon than the vegetation of all other landforms on Earth combined.

For decades, gardeners and horticulturalists have worked to reduce the use of peat and to preserve peatlands. These efforts have been particularly forceful in the United Kingdom, where peatlands make up 12% of the land area and, in 2020, peat accounted for 41% of all plant growing media, according to Peat-free Horticulture: Demonstrating Success. The UK’s Royal Horticultural Society is a leader on peat-free initiatives and is committed to eliminating peat from RHS gardens, plant shows, and plant sales by 2025, as outlined in the RHS peat policy. It also is committed to educating its members and the general gardening public on the value of peat and the environmental impact of its continued use for gardening.

The RHS has been researching substitutes and offers peat-free composts for sale. If gardeners and the horticultural industry beyond the UK are to go peat-free, alternatives to peat need to become better known and easy to purchase. Until peat-free potting soils and soil conditioners are more widely available in the US, which obtains most of its horticultural peat from Canada, consider one of these options:

Coconut fiber, or coir, is waste generated from the coconut industry, and is described as a reusable and sustainable resource, although it must be processed before use and shipped considerable distances. The fibers are lightweight and expandable, similar to peat, and improve soil water retention and air infiltration capabilities.

Commercially available or made at home, compost is decomposed plant material that adds nutrients to the soil and improves aeration. In contrast to peat, compost is the result of an aerobic process, with microbes using oxygen to break down a mix of green (vegetable scraps, grass clippings) and brown (paper, straw, wood chips) plant matter.

Leaf Mold – A Possible Alternative to Peat

Leaf mold is a soil conditioner and mulch that is the product of fall leaf drop. Leaf mold can be created simply, by letting leaves accumulate in garden beds in the fall and working them into the soil as they decay, or with a bit more effort, by shredding the leaves and keeping them slightly wet to accelerate the decaying process. As with compost, leaf mold adds nutrients to the soil.

Another option? Work with existing conditions. Instead of trying to transform soil into an unrealistic ideal that is not typically found in your region, choose plants that tolerate the clay, sand, or other soil conditions in your garden. This naturalistic approach connects the garden to the local environment and may lead to greater sustainability over time.

Whether classified as a fen, mire, tropical swamp forest, or permafrost bog, peatlands are landforms of such environmental significance that organizers of COP26, the 2021 UN Climate Change Conference, invited attendees to an in-person and virtual Peatland Pavilion to describe the role of peatlands in addressing climate change. With their unique ecology and thousand-year histories, peatlands also are places of mystery and beauty. Reconsidering peat in the garden is one way to contribute to their survival.


Notes

  1. International Union for the Conservation of Nature. IUCN Issues Brief: Peatlands and climate change. Last reviewed: November 2021. Accessed January 22, 2022. https://www.iucn.org/resources/issues-briefs/peatlands-and-climate-change
  2. Holmes, S. & Bain, C. (2021) ‘Peat-free Horticulture – Demonstrating Success’, IUCN UK Peatland Programme, Edinburgh. October 2021. Accessed January 22, 2022. Download from the Demonstrating Success Booklet Series website at https://www.iucn-uk-peatlandprogramme.org/resources/restoration-practice/demonstrating-success
  3. Royal Horticultural Society. RHS peat policy. Accessed January 22, 2022. https://www.rhs.org.uk/about-the-rhs/policies/rhs-statement-on-peat
  4. IUCN UK Peatland Programme. Peatland Pavilion at COP26. Accessed January 22, 2022. https://www.iucn-uk-peatlandprogramme.org/events/peatland-pavilion-cop26

If you’d like to read more . . .

Bek, D., Lennartsson Turner, M., Lanari, N., Conroy, J., & Evans, A. (2020). Transitioning towards peat-free horticulture in the UK: an assessment of policy, progress, opportunities and barriers. https://hta.org.uk/uploads/assets/219d3ce6-e9a2-4659-b0a52d7a1bd6dd1e/FINALCOVNTRYUNIREPORT-HTAGMAFinalCoversauthors29Sept20-1.pdf. Accessed January 24, 2022.

Birnbaum, Christina & Wood, Jennifer & Lilleskov, Erik & Lamit, Louis & Shannon, James & Brewer, Matthew & Grover, Samantha. (2022). Peatland Degradation Reduces Microbial Richness and Alters Microbial Functions in an Australian Peatland. Accessed January 24, 2022. https://www.researchgate.net/publication/357855371_Peatland_Degradation_Reduces_Microbial_Richness_and_Alters_Microbial_Functions_in_an_Australian_Peatland

CongoPeat: Past, Present and Future of the Peatlands of the Central Congo Basin. Accessed January 24, 2022. https://congopeat.net/

Gustaf Hugelius, Julie Loisel, Sarah Chadburn, Robert B. Jackson, Miriam Jones, Glen MacDonald, Maija Marushchak, David Olefeldt, Maara Packalen, Matthias B. Siewert, Claire Treat, Merritt Turetsky, Carolina Voigt, Zicheng Yu. Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw. Proceedings of the National Academy of Sciences Aug 2020, 117 (34) 20438-20446; DOI: 10.1073/pnas.1916387117. Accessed January 24, 2022.

IUCN UK Peatland Program. International Union for the Conservation of Nature, National Committee, United Kingdom. Accessed January 24, 2022. https://www.iucn-uk-peatlandprogramme.org/

Martignoni, Jimena. “Bog Wild.” Landscape Architecture Magazine. June 2022, 112 (6) 100-113.

Nair, Anila. “A Case Against Peat.” Fulton From the Ground Up. University of Georgia Extension. June 15, 2021. Accessed January 24, 2022. https://site.extension.uga.edu/fultonag/2021/06/a-case-against-peat/

Peat and Peatlands. Canadian Sphagnum Peat Moss Association, New Brunswick Peat Producers Association, Quebec Peat Moss Producers Association. Accessed January 24, 2022. https://peatmoss.com/

Peatlands. International Peatland Society. Accessed January 24, 2022. https://peatlands.org/peatlands/

“What’s so special about peat?” National Trust. Accessed January 24, 2022. https://www.nationaltrust.org.uk/features/whats-so-special-about-peat

Designing with Natural Light in the Garden

In the morning, as the sun is rising, a special quality of light touches the garden. Plants appear fresh, even during a dry spell, with imperfections hidden in shade. Bare, compacted areas look mulched in the dim light, and even faded colors shine as the sun’s rays highlight one side of a tree’s foliage or individual flowers in a perennial bed.

Then it’s noon, and the magic show is over. The scene is bleached and shadeless, flat. Check back around sunset and another version of the garden emerges, as the angled and golden western light tints blossoms, leaves, and bark.

Intentional or not, this natural light affects how we see. It has the power to capture attention, turning an ordinary garden into a memorable experience. Natural light becomes a design element, along with color, texture, landform, and plant type. How can we include this element in a garden design plan and control its impact on what we perceive?

Amsonia in Western Light in Fall

Observation is a key first step. Spend time watching plants in your garden throughout the day, and you’ll discover which ones stand out in the morning and evening sun. Visit other gardens and notice how light works. Photograph plants when they’re at their highlighted best and when they’ve receded and record the position of the sun and the type and siting of the plant. The effects of natural light on the garden, and the relationship of sun angle and plant placement, begin to make sense. If you’re looking for inspiration on how to observe, the book Mountain Light by photographer Galen Rowell is a beautiful guide. The focus is on alpine light, but Rowell’s lessons for appreciating light and landscapes can easily be adapted to garden design.

Next, think about color. Which colors work well in the morning and evening, and are there any that make a statement at mid-day? Which colors are best at different times of the year? Pastels may look calming and welcoming in the gently shaded light of morning but can disappear in direct light. Vivid, saturated colors may feel a little tamped down in morning light but hold up at mid-day and can be stunning in the rays of evening. A mix of colors can invigorate the garden, especially as the sun touches leaves and blossoms emerging in the spring or foliage beginning to turn in the fall. A color theme — variations of a particular color repeated throughout the garden — provides a coordinated approach, as light travels from one patch to another. Color is a topic with many questions to explore, and Sandra Austin’s Color in Garden Design is a good resource for understanding the science and art of color, including the impact on color of different kinds of garden light.

Another aspect to consider is plant texture. With fine to coarse leaf shapes and rough to smooth leaf surfaces, a plant’s texture absorbs, reflects, and concentrates light. Think of the halo effect of sunlight on the soft plumes of flowering ornamental grasses, the contrast of a holly’s glossy leaves and the wrinkled leaves of witchhazel, and the irregularities and varying depths of the bark of maples, oaks, and hickories. Textures supplement color as a means for catching light.

Plant shape has an impact. Natural light seeks out opposites: plants that rise above their companions, stretch further horizontally, or drape or weep in contrast to the more rigid architecture of their neighbors. Single plants positioned to take advantage of backlighting, side light, or front light can be amazing focal points. Massed plants provide a different effect, filling the field of sight with washes of color or texture.

Start the design process by returning to the discoveries revealed through observation. What is the orientation of the garden — does it face north, south, east, or west? Are existing plants already illuminated by light, and if so, would increasing the number improve the effect? If no focal points for light currently exist, are there blank spots in the garden that could benefit from their addition? Which colors, textures, and shapes might work for these spaces and do existing colors, textures, and shapes need to be modified?

Combine these observations and think about framing views. Pick a few of the most important views — from inside the house or from the street as you approach the house or from an area within the garden — and identify the frame. It could be an interior structure such as a window, an exterior structure such as a gate or portal, or a frame created by plants. Often the garden frame provides a view from shade to an area of sun, which becomes a focal point, but reversing the perspective and framing a shaded area creates a sense of mystery, encouraging a closer look.

Choose plants based on your observations, on color, texture, and shape, and using additional factors that might include whether a plant is native, pollinator-friendly, evergreen, or deciduous. Settle on the views to frame, begin to place the plants, and watch the results. And if this approach seems more easily described than implemented, keep in mind one of the best features of natural light: you can enhance it as a design element, by deliberate selection and placement of plants, but even if you don’t control its impact, it will continue to work wonders in your garden. All it takes is a bit of attention to see its ever-changing effects.


Morning Light in Spring
Direct Light in Spring

Notes

1. Austin, Sandra. Color in Garden Design. Newtown, CT: The Taunton Press, 1998.
2. Rowell, Galen. Mountain Light. San Francisco: Sierra Club Books, 1986.

Why It’s Not a Good Idea to Plant a Butterfly Bush

The butterfly bush — Buddleja, or Buddleia, davidii and other species — is a butterfly magnet, with fragrant, tapered clusters of lavender, pink, yellow, or white blossoms emerging on arching branches from summer into fall. An easy to grow, rapidly developing shrub, it seems a good choice for the pollinator garden.

But it’s not. A butterfly bush is a food source for butterflies, but it is not a host plant, and understanding the difference is key to understanding why butterfly populations are declining and what gardeners can do to slow this trend.

Asclepias tuberosa (Butterfly Weed) — A good alternative to the butterfly bush

Host plants may produce nectar, but their primary role is to support the next generation by providing butterfly larvae — the caterpillars that hatch from butterfly eggs — with the nourishment they need. At the larval stage, nourishment comes from the plant’s leaves, which the caterpillars consume to support their growth and eventual transformation (pupation) from caterpillars to adult butterflies.

The host plant-larval relationship is remarkably specific. Butterfly larvae will not eat the leaves or any other parts of the butterfly bush, and the adult monarchs and swallowtails that stop by for nectar must find host plants on which to deposit their eggs. For monarchs, that means milkweed. If host plants are not available, a critical part of the butterfly life cycle cannot be completed, and over time, populations decline.

Planting butterfly bushes plus host plants, it seems, would meet all the requirements by providing nectar plus a larval food source. But there’s another problem with butterfly bushes, and that’s their ability to spread in the wild and outcompete native shrubs.

Introduced from Asia in the early 1900s, butterfly bushes are a popular garden shrub and have been widely planted. With highly dispersible seeds, they easily escape from gardens and establish themselves in woodlands, reducing the number of native nectar and host plants, and in turn, reducing the number of butterflies. In Maryland and other Mid-Atlantic states, butterfly bushes are designated as problem plants and appear on invasive species lists.

You can compensate for the impact of the butterfly bush on native species, and support the developmental needs of butterfly larvae, by planting a mix of native nectar and host plants that bloom throughout the year: milkweed (Asclepias) for monarch butterflies, asters for the pearl crescent, spicebush for the spicebush swallowtail, dogwood and viburnum for the spring azure, and black cherry and birch for the tiger swallowtail.

This approach opens a window onto the diversity and complexity of nature and the challenge, but also possibility, of creating a more natural garden. It requires research and a bit of investment in design. Is it worth the time? It is, if it’s important to know that you’re not just attracting butterflies to your garden but helping them survive.


If you’d like to read more . . .

Adelman, Lauren. “The Joy of Butterfly Host Plants.” Lewis Ginter Botanical Garden. Jul 5th, 2017. Accessed August 29, 2021.
https://www.lewisginter.org/butterfly-host-plants/

“Butterfly Gardening Information.” Rainscapes. Department of Environmental Protection, Montgomery County, Maryland. Accessed August 29, 2021.
https://www.montgomerycountymd.gov/DEP/Resources/Files/downloads/rainscapes/fact-sheets/ButterflyGardenPlantList.pdf

“butterflybush: Buddleja davidii.” Invasive Plant Atlas of the United States. Accessed August 29, 2021.
https://www.invasiveplantatlas.org/subject.html?sub=11608

Carignan, Christa and Debra Ricigliano. “Butterfly Bush.” University of Maryland Extension. Updated April 13, 2021. Accessed August 29, 2021.
https://extension.umd.edu/resource/butterfly-bush

“Creating a Wild Backyard – Bad Plants Planted by Good People.” Maryland Department of Natural Resources. Accessed August 29, 2021.
https://dnr.maryland.gov/wildlife/Pages/habitat/wabadplants.aspx

Espindola, Anahi. “What’s the deal with butterfly bushes: Good or bad for pollinators?” Maryland Grows Blog. Posted on September 14, 2020. Accessed August 29, 2021.
https://marylandgrows.umd.edu/2020/09/14/whats-the-deal-with-butterfly-bushes-good-or-bad-for-pollinators/

Landscaping with Native Plants. Maryland Native Plant Society. Accessed August 29, 2021.
https://www.mdflora.org/publications/gardenersguidelines/gguides.html

Schmidt, Lillia and Susan Charkes. “Invasive Species Spotlight: The Truth about Butterfly Bush.” Conservancy Blog, Brandywine Conservancy and Museum of Art. June 7, 2020. Accessed August 29, 2021.
https://www.brandywine.org/conservancy/blog/invasive-species-spotlight-truth-about-butterfly-bush

Schmotzer, Constance. “Avoiding Invasives: Butterfly Bush.” PennState Extension. Updated April 26, 2017. Accessed August 29, 2021.
https://extension.psu.edu/avoiding-invasives-butterfly-bush


Note: The original draft of this post was written on August 29, 2021.


National Native Plant Month – April 2021

Recognition of the value of native plants continues to grow. Senate Resolution 109 of the 117th Congress, which designates April 2021 as National Native Plant Month, passed with bipartisan support on March 25. The resolution “recognizes the benefits of native plants to the environment and economy of the United States.” See Text – S.Res.109 – 117th Congress (2021-2022) for the full resolution and the actions taken for passage.

What is a native plant? The resolution states that “native plants are indigenous species that have evolved and occur naturally in a particular region, ecosystem, and habitat.”

On its Why Native Plants Matter webpage, the National Audubon Society defines native plants as “those that occur naturally in a region in which they evolved.”

According to the Native Plants webpage of the National Wildlife Federation, “A plant is considered native if it has occurred naturally in a particular region, ecosystem, or habitat without human introduction.”

And under the Frequently Asked Questions section of The PLANTS Database, from the United States Department of Agriculture, the response is that “In PLANTS, native means naturally occurring at the time of Columbus. Introduced plants arrived later, invariably with human assistance, from some other part of the world.”

Virginia Sweetspire Flowers

The Butterfly Effect of a Wildlife Garden

A wildlife garden is designed intentionally to attract birds and butterflies and other pollinators, not just because they’re enjoyable to watch, but because they need help to survive.

Wildlife gardens compensate for habitat destruction, pesticide use, and climate change by adding feeding grounds, nesting sites, and migratory way stations to the larger ecosystem. They shore up, if only on a small scale, bird and pollinator populations that are in decline.

Reports of these declines appear regularly. Three billion North American birds have vanished since 1970, according to a frequently cited 2019 study published in the journal Science. The monarch butterfly population overwintering in Mexico declined 53% compared with the previous year, WWF-Mexico states in its latest survey. Other studies recently released by the Proceedings of the National Academy of Sciences estimate that 1% to 2% of all insect species are disappearing every year.

At stake from these losses is the survival of flowering plants, including agricultural crops, which rely on bird and insect pollinators for their reproduction.

A wildlife garden is a way to stem the losses, on an individual level. Much of this mitigation is accomplished with native plants, which co-evolved with birds and insects to provide the specialized food—pollen, nectar, berries, and insect larvae—they require. Asters and agastache attract bumble bees, butterfly weed supports new generations of monarch butterflies, and native oaks feed the larvae of hundreds of moth and butterfly species, which parent birds seek out as protein sources for their nestlings.

These plantings result in gardens of unique beauty and often meadow-scale size that combine a kaleidoscope of color with uncommon shapes. Purple coneflower and black-eyed Susans mash up with spiky five-foot tall rattlesnake master, but then there’s the daintiness of wild petunia and the gracefulness of wild indigo. It’s a garden that may appear uncontrolled, but as with any garden, the design can be tamed. What cannot be tamed is the buzzing, fluttering, and humming of a garden alive and working.

Creating a wildlife garden is a way to restore a link in a broken chain.

That’s the reasoning. But before getting started, it might be useful to ask, do I need a meadow? Can my sixth of an acre lot or 6’ x 6’ raised bed really help birds and pollinators survive? If I only have room for a patch of milkweed, am I still contributing to a kind of literal butterfly effect?

When it comes to gardens, says Doug Tallamy, author of Bringing Nature Home and Nature’s Best Hope, “size may not matter as much as we think. Every plant is valuable.”

He gives the example of migration. “Even one tree. Migrating birds will find it,” and will refuel on the insect larvae it supports, improving their chances for survival as they fly north to their breeding grounds.

There is a caveat. “Plant anything as long as it’s native,” says Tallamy. Butterfly bushes and other nonnative ornamentals may be beautiful and produce a lot of nectar, but these plants don’t support specialist species, the native bees and butterflies that are in decline.

To recreate nature is impossible, but gardeners may have more power than they realize to restore nature, even if on a tiny scale. And if neighbors join together, the links multiply, and “then you really have habitat.”

Small steps add up. Every butterfly counts.

Deborah Ozga
April 17, 2021

Agastache with Eastern Tiger Swallowtail

This post is a reworked version of a previous post, The Wildlife Garden, and was completed while participating in a class at The Writer’s Center in Bethesda, Maryland.

To learn how you can support ecosystem health and biodiversity through gardening, and amplify the butterfly effect, visit the Homegrown National Park website.


The Wildlife Garden

Wild Petunia (Ruellia humilis) and Coreopsis

No matter how simple or complex, designed or haphazard, a garden is an ecosystem, a community of plants and animals interacting with the environment of a space — the sun, wind, rain, and soil. A wildlife garden is an ecosystem designed intentionally to attract birds and butterflies and other pollinators, not just because they’re enjoyable to watch, but because they need help to survive. Wildlife gardens compensate for habitat fragmentation and destruction by adding feeding grounds, nesting sites, and migratory way stations to the larger ecosystem, making up, if only on a small scale, for some of what has been lost.

In the Mid-Atlantic, an enthusiastic community of researchers and garden educators advanced the cause of wildlife gardening in 2020 through webinars, lectures, and courses sponsored by several environmental and gardening organizations. The speakers explained why it makes sense to create urban gardens that support wildlife, even if pocket-sized (Wildlife Gardening Workshop, Patterson Park Audubon Society), explored the data and science underlying the philosophy of wildlife gardening (Turning the Tide: A Practical Guide for Bringing Nature Home, Community Conservation Committee (C3) and Lancaster County Master Gardener Program — Penn State Extension), and in a three-session course, Inviting Wildlife into the Garden (Mt. Cuba Center), provided tips on attracting wildlife, discussed why native bees and other insects are essential for the survival of flowering plants, and described how to create a garden that meets the needs of migrating birds and hummingbirds.

From what I could tell as a fellow participant, audience members were ready to embrace wildlife gardening, despite its challenges. It takes research and thought to create a wildlife garden that succeeds ecologically and aesthetically. The commitment to giving it a try was heartening.

Plant layering is an essential component of wildlife gardens and one of the challenges. By installing plants of varying heights and differing roles, and preferably species that appear together in nature — canopy and midstory trees, understory shrubs, perennials, and ground covers, and for the perennials, mixing specimens that are upright, mounding, and trailing — the ecosystem knits together in a way that feeds and shelters wildlife. It becomes a plant community, similar to a natural landscape or the woodland edge of the neighborhood park down the street, which in the early morning is filled with birdsong.

Agastache with Eastern Tiger Swallowtail

When my garden fills with birdsong, it’s often in response to feeders packed with suet and black oil sunflower seeds. If I remove the feeders, I lose the diversity of birds and the density. My garden is not yet a wildlife garden, a landscape that, through its plant selections and designed plant communities — its layering — provides food (insect larvae, berries, seeds), nesting sites, and safe spaces for birds, bees, butterflies, and other creatures.

I’ve tested how a wildlife garden might work, by planting a few native perennials, and the process is rewarding: agastache and asters brought in bumble bees and swallowtails, cardinal flower led to daily hummingbird visits, and butterfly weed supported a new generation of monarch butterflies. These individual plantings can be magical attractions, with ruby-throated hummingbirds and monarchs materializing as if through spontaneous generation, but they are only parts of a plant community and do not offer a succession of resources for wildlife throughout the year. That’s where another challenge emerges, of designing a garden that is not only visually appealing in all seasons, as a garden should be, but that offers sustenance and shelter to wildlife from January through December.

To recreate nature is impossible, but attempting to build an inviting garden with wildlife-supporting plant communities provides insight into how nature works, especially the relationship between plants and pollinators. Understanding nature’s complexity encourages more experimentation to see if nature can at least be approximated, and a reinforcing loop that benefits wildlife begins.

In the last year and a half, at least three significant wildlife population declines have been reported, in North American birds1, wild bees2, and monarch butterflies3. Creating wildlife gardens is one step gardeners and landscape designers can take toward reversing these declines. We owe a debt of gratitude to those who have been leading the way.


Notes

  1. “Nearly 3 Billion Birds Gone.” Birds, Cornell Lab of Ornithology. Cornell University. Accessed January 2, 2021. https://www.birds.cornell.edu/home/bring-birds-back
  2. Rutgers University. “Decline of bees, other pollinators threatens US crop yields.” Science X. July 28, 2020. Accessed January 2, 2021. https://phys.org/news/2020-07-decline-bees-pollinators-threatens-crop.html
  3. Curry, Tierra. “Eastern monarch butterfly population plunges below extinction threshold.” Center for Biological Diversity. Science X. March 20, 2020. Accessed January 2, 2021. https://phys.org/news/2020-03-eastern-monarch-butterfly-population-plunges.html

If you’d like to read more . . .

Holm, Heather. Pollinators of Native Plants: Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants. 2014. Minnetonka, Minnesota: Pollination Press LLC.

Oudolf, Piet and Henk Gerritsen. Planting the Natural Garden. 2019. Portland, Oregon: Timber Press.

Oudolf, Piet and Noel Kingsbury. Planting: A New Perspective. 2013. Portland, Oregon: Timber Press.

Rainer, Thomas and Claudia West. Planting in a Post-Wild World: Designing Plant Communities That Evoke Nature. 2015. Portland, Oregon: Timber Press.

Tallamy, Douglas W. Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard. 2020. Portland, Oregon: Timber Press.

Weaner, Larry and Thomas Christopher. Garden Revolution: How Our Landscapes Can Be a Source of Environmental Change. 2016. Portland, Oregon: Timber Press.

The Xerces Society for Invertebrate Conservation. Accessed January 2, 2021. https://xerces.org/


Note: The original draft of this post was written on January 1, 2021.

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