54. Heather Holm on Pollinators and Native Plants

HEATHER HOLM BIO

Heather Holm is a pollinator conservationist and award-winning author of four books: Pollinators of Native Plants, Bees, Wasps, and Common Native Bees of the Eastern United States . Both Bees and Wasps have won multiple book awards including the American Horticultural Society Book Award. She is the founder and chair of Minnesota Native Bees, an online field guide illustrating the native bees of Minnesota and beyond. Heather’s expertise includes the interactions between native pollinators and native plants, and the natural history and biology of native bees and predatory wasps. Her work has been featured in The New York Times, Minneapolis Star Tribune, and many local publications. Heather is also an accomplished photographer and her pollinator photos are frequently featured in print and electronic publications.

In her spare time, she is an active community supporter, writing grants, and coordinating and participating in volunteer ecological landscape restoration projects of fire-dependent ecosystems. The latest project is a 13-acre oak savanna restoration that will provide thriving habitat for pollinators, birds, mammals, and passive, nature-based opportunities for people. ​ 

You can learn more about Heather at her website pollinatorsnativeplants.com, and check out her Minnesota bee field guide nonprofit at beesmn.org

SHOW NOTES

• Fifth grade coleus cuttings rooting in a glass jar as an early plant memory

• Learning tree identification from her father

• Horticulture degree followed by biological sciences, with early entomology too focused on pest control to be inspiring

• Moving to Minnesota and discovering the insect diversity of native landscapes

• Joining a university pollination study group to get up to speed on bees

• Web development, graphic design, and darkroom photography as transferable skills that now bring insects to life visually

• Noticing highly specific patterns of insect visitation to certain plants year after year as her turning point

• A beetle on mountain mint that hitchhikes its larvae onto bees and wasps back to the nest

• Scientific American article on bees

• Berry crop research showing farms near diverse habitat can achieve 100% pollination from native bees alone

• Farms surrounded by conventional corn and soy struggling with inadequate native bee pollination

• Deep involvement in ecological restoration, fire ecology, rare bee documentation, and a new Minnesota bee field guide nonprofit

• Hemiparasitic plants like Pedicularis canadensis (wood betony), Comandra umbellata (bastard toad flax), and Aureolaria sp. (false foxgloves) as missing pieces in garden design and restoration

• Prescribed fire increasing floral diversity and being extremely beneficial for bees despite public perception

• Neighboring landscape context as a major factor that home gardens cannot fully replicate

• Flower shape, complexity, and nectar guides determining which insects can access a given flower

• Not every insect visit to a flower results in pollination

• Monarchs commonly called pollinators despite lack of published research confirming they pollinate plants

• Buzz pollination (sonication) and its importance for plants like blueberries

• The southeastern blueberry bee as an eclectic pollen specialist also collecting redbud and lupine pollen

• Southeastern Blueberry Bee: Georgia Native Blueberry Pollinator

• Pollen specialists making up 30–40% of bee species depending on location

• About 90% of native bees are solitary with a roughly 12-month egg-to-adult life cycle

• Offspring spending up to 10 months in a prepupal stage underground before emerging

• Sandy, well-drained soil can support higher bee diversity

• Bees that prefer bare soil often nesting gregariously in clusters

• Bee diversity highest in arid regions like the Southwest and Texas

• Leafcutter bee cuts on rose leaves as visible evidence of nearby nesting activity

• A small mason bee chewing wild strawberry leaves into a leaf pesto to line her nest

• Logs, stem stubble, and leaf litter as overlooked nesting habitat

• Soft landings as diverse native plantings under keystone trees to give dispersing caterpillars a safe place to pupate

• University of Maryland study finding raked yards had fewer arthropods and fewer butterflies and moths

• Using small plugs and adding organic matter slowly when establishing soft landings under trees

• Social wasps representing less than 5% of all wasp species, with the vast majority solitary and non-aggressive

• Residential mosquito spraying, including products marketed as organic, being highly toxic to all pollinators

• High insect visitation to non-native plants not telling the full story; most may be nectar-feeding rather than collecting pollen for nests

• Influence of Plant Taxa on Pollinator, Butterfly, and Beneficial Insect Visitation

• Nectar as carbohydrate fuel; pollen as the fat- and protein-rich food female bees provision nests with

• Leaving 8 to 20 inches of stem stubble on pithy-stemmed perennials as nesting habitat for small carpenter and mason bees

• Offspring from stem nesters not emerging until a full year after the nest is provisioned

• Female eggs laid at the back of the stem, male eggs near the front, with females receiving more food and emerging later

• Focusing stem stubble efforts on Aster family plants — black-eyed Susan, goldenrod, and coneflowers

• Native willows, dogwoods, ericaceous shrubs, leadplant, and red maple as top woody plants for supporting specialist bees

• Looking up into flowering trees in spring, not just down, to find bee activity

• Oil bees combing oil from native loosestrife (Lysimachia) trichomes to waterproof their ground nests

• The cellophane bee Colletes ciliatus specializing on Cuscuta glomerata (rope dodder), a parasitic annual vine that shifts location each year

• Planting natives from neighboring regions in gardens to extend bloom periods and support pollen specialists

• Being a lifelong learner and staying open to tangential subjects as her core professional practice

• The dandelion-as-first-bee-food myth as something that irks her — diversity is always the answer

• The Eternal Frontier by Tim Flannery as a recommended read on North American ecology across deep time

• Slowing down to document pollinators using iNaturalist or the Seek app as her single ask for listeners

• You can learn more about Heather and her books at pollinatorsnativeplants.com, and check out her Minnesota bee field guide nonprofit at beesmn.org.

KEEP GROWING

51. Shaun McCoshum on Natural Habitats and Wildlife Gardening

SHAUN MCCOSHUM BIO

Shaun McCoshum is a certified, Senior Ecologist and Wildlife Biologist with over 20 years of experience restoring habitats, conducting research, and gardening. His work includes published scientific papers, books, and copious restoration plans from coast to coast including lands with bison, endangered plants, threatened pollinators, black bears, and mountain lions. His new book explores the pre-European ecology of North America and how habitats existed and explains how we can better mimic processes in our own yards to support habitat. 

Shaun has kindly offered podcast listeners a discount of 30% of his new book! Use the code NHWG30 at the Princeton University Press website.

SHOW NOTES

• Growing up gardening with his grandmother and learning to view pests as puzzles to solve

• His PhD research on whether canola crops could benefit or harm native bee populations in Oklahoma

• Canola requiring significantly more pesticides and insecticides than other crops due to aphid pressure

• Working as a preserve manager for Westchester Land Trust outside New York City, overseeing independently owned preserves

• Cutting down native red maple to restore shrub habitat, one of the only remaining habitats for shrub-dependent bird species

• His current work as a senior ecologist at Westwood Professional Services, conducting habitat assessments for developers

• Evaluating sites under the Endangered Species Act to determine where development should or should not occur

• Developing vegetation management plans for solar facilities to establish biodiverse habitat underneath solar panels

• Protecting wetland buffers during pipeline work and using horizontal directional drilling to pass pipelines underneath wetlands

• His postdoctoral research examining pollinator declines at solar facilities in the Mojave and Sonoran deserts

• Transforming his front yard in Odessa, Texas from a Bradford pear and lawn to a native scape, increasing bee species from 5 to over 50

• His book, Natural Habitats and Wildlife Gardening, born out of widespread misconceptions he encountered in presentations

• The common misconception of "just let nature take its course" and why unmanaged gardens do not restore themselves

• Bee hotels mimicking dead logs, and why they stop working after a year or two without maintenance

• How plants in natural systems are meant to be grazed, trampled, and eaten, triggering anti-herbivory compounds that make them healthier

• The missing role of bears in spreading ocean-derived nutrients as fertilizer across the interior landscape through consuming anadromous fish

• Adding light manure to garden beds every three to five years to replicate the slow-release fertilizer large animals once provided

• The missing role of bison and other large herbivores in breaking down old vegetation and creating layered ground cover for seedling germination

• Trimming back plants selectively to stimulate more blooms, seed heads, and anti-herbivory responses

• The first principle of habitat gardening: evaluate the space from the perspective of the organisms you want to support across their full annual cycle

• Creating pockets of sandy or clay soils for ground-nesting bees

• Burying organic matter to replicate the decaying wood environments that beetles and moths need to pupate

• Creating underground hollow shelters to replicate abandoned burrows for toads and other wildlife

• Broadening pollinator gardens to intentionally support both bees and moths for a larger habitat umbrella

• Why gardeners tend to think in objects rather than systems, and how American cultural independence may contribute to that

• Native plants working with underground microbial communities, precipitation patterns, and temperature cycles rather than growing in isolation

• Any landscape design style can be achieved with native plants, including formal topiaries using plants like Texas sage shaped by heavy browsing

• Native junipers and blueberries tolerating heavy pruning, with a list in the book of natives that respond well to formal shaping

• Decay being the most suppressed natural process in suburban and urban landscapes

• The Eastern Bluebird recovery as a model for reversing decline by replicating a single missing habitat element

• Removing leaves and then buying mulch as one of the most counterproductive common gardening practices

• Allowing leaf litter to break down in place to provide overwintering habitat, nesting material, and food for soil microbes

• The best activity for a small balcony with three or four pots: planting sunflowers for pollinators, caterpillars, and seed-feeding birds

• Shorter alternatives including aster, fire wheels, Gaillardia, and Tithonia daisies, and avoiding heavily hybridized plants like chrysanthemums

• For slightly larger spaces, burying untreated wood chips to create underground pupation habitat for beetles and moths

• How to build the underground habitat pocket: no lining, pack in wood chips, add light soil on top, avoid low spots that collect water, treat as a one-time installation

• Ethan Tapper's work on mimicking old growth forests by adding specific resources like downed wood

• How coyotes improve bird habitat by driving out nest-predating meso-predators like foxes and raccoons

• The trophic cascade in Yellowstone where wolf reintroduction stabilized stream banks and brought back fish populations

• Oaks as host plants for over 200 species of moths alone, with the option to cut one back to shrub size in small spaces

• Bears as promoters of fleshy fruit-producing plant communities, with seeds from bear scat germinating at dramatically higher rates

• Ramial wood chips from young branches used in holistic orchard management, independently mirroring the natural process of large animals trampling material under trees

• Using dead wood as garden bed borders, pedestals for container plants, and structures for vining plants

• Root masses left standing after tree removal as architectural focal points, with examples from Tulsa after windstorm damage

• Building underground hollow shelters into raised beds using upside-down kennel tops covered with stones or logs

• The Gopher tortoise burrow as an ecosystem engineering example, with over 200 species documented using a single burrow

• Prairie dog towns hosting over 400 coexisting species, illustrating how underground structures support biodiversity

• Dr. Doug Tallamy's research showing gardens with 70% native plants have no statistical difference in biodiversity from 100% native

• Using the 30% non-native allowance to place recognizable garden plants at the front where neighbors can see intentional design

• Propagating Greg's mistflower for five neighboring houses in Corpus Christi simply because neighbors found it pretty

• Observing insects and wildlife closely without assigning intent as a calming daily practice, including noticing monarchs probing bell pepper plants for aphid honeydew

• Foraging edible plants from the landscape as a personal practice

• Flora: The Gardener's Bible, chief consultant Sean Hogan, as a reference for baseline plant information that shaped a generation of gardeners

• Busting the myth that native plants and habitat gardens are inherently messy

• Meeting people where they are when introducing native plants, leading with beauty, edibility, or fragrance rather than ecological function

48. John Little on Caring for Gardens and Gardeners

JOHN LITTLE BIO

John Little has been reimagining what urban nature can be since founding the Grass Roof Company in 1998. Over the past 25+ years, John has designed and built more than 400 small green-roof structures and various other species-rich planting with walls engineered for nesting, hibernation, and year-round habitat.

His nonprofit Care Not Capital pushes for a fundamental shift to redirect funds from one-off capital projects toward ongoing, human-powered stewardship that benefits both biodiversity and communities.

Here are the core ideas John argues for—putting the best gardeners in the poorest places, moving money from capital into care, understanding that gardened places are best for biodiversity and people, moving novel landscapes higher up the Biodiversity Net Gain (BNG) metric, understanding that a modern public space gardener is much more than a horticulturist, keeping waste on site and using it to make places beautiful and biodiverse, and putting soil and plants on roofs.

You can connect with John on Instagram at @grassroofco and @carenotcapital and support Care Not Capital here.

SHOW NOTES WITH APPROXIMATE TIME STAMPS

• (00:00) Introduction

• (01:00) Early influences and growing up with a permaculturist grandfather and in post-industrial landscapes

• (03:00) From retail to professional horticulture without formal training

• (04:00) The shift from native plants to wildlife and habitat creation

• (05:00) Green roof experimentation and breaking free from conventional substrate wisdom

• (08:00) Topography as an underplayed design tool

• (10:00) Effects of putting substrate on top of soil

• (13:00) The art of seeing landscapes

• (17:00) The importance of ruderal vegetation and hand weeding for biodiversity

• (19:00) Care Not Capital and investing in gardeners instead of infrastructure

• (22:00) Lessons from social housing and listening to residents over imposing ideas

• (25:00) Free training for gardeners in community engagement, ecology, and green infrastructure

• (28:00) Creating structural habitat with dry stone walls, cob buildings, and dead wood

• (33:00) Redesigning horticulture education

• (37:00) Valuing bare ground and the importance of entomologists in design

• (40:00) Balancing ecology with aesthetics while making it beautiful for humans and wildlife

• (44:00) Working in poorest communities and why green space investment matters most there

• (49:00) Practical advice for home gardeners on working with subsoil and alternative substrates

• (54:00) Managing lawns, dead trees, and organic debris for habitat

• (58:00) Bee hotels and using gabions as multifunctional habitat structures

• (64:00) Thoughts on bringing materials onto a site

• (68:00) Recommended reading of Rebirding and Cornerstones Benedict Macdonald and understanding natural European habitats

• (69:00) Thinking about climate change and succession in design

• (71:00) How to propagate more gardeners by making them celebrities and funding good jobs

• (73:00) You can connect with John on Instagram at @grassroofco and @carenotcapital and support Care Not Capital here.

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KEEP GROWING

44. Kelly Holdbrooks on Southern Highlands Reserve

KELLY HOLDBROOKS BIO

With decades of experience in Western North Carolina’s vast horticulture, Kelly Holdbrooks demonstrates her passion for fostering human connection with nature in everything she does. For more than a decade as executive director of Southern Highlands Reserve, a nonprofit native plant garden and research center on Toxaway Mountain, Kelly has built a network of conservationists and advocates for preserving the unique ecosystem of the Southern Appalachian Mountains. Kelly’s research in experiential methods and the humanism of nature earned her a master’s degree in landscape architecture, with honors, from the College of Environment and Design at the University of Georgia. She also earned bachelor’s degrees in international studies and political science from Rhodes College and was a three-sport NCAA athlete. She is a founding member of the Southern Appalachian Spruce Restoration Initiative (SASRI), a public-private partnership working to restore the second most endangered ecosystem in the United States, the high elevation spruce-fir forests of the Southern Blue Ridge. She is a member of the Red Spruce Technical Advisory Board (RSTAB), headed by The Nature Conservancy, to make recommendations to the U.S. Forest Service for their regional planning efforts. She also participates in the quarterly All Lands Meeting held by the U.S. Forest Service to develop a long-term collaborative plan for natural resource conservation across Region 8. Kelly enjoys hiking, gardening, yoga, and playing in nature with her family. She is proud to call Western North Carolina her home.

You can learn more about Kelly and Southern Highlands Reserve by visiting their website and Instagram @southern_highlands_reserve.

SHOW NOTES

• How Kelly's childhood in Tennessee and family garden experiences ignited her love for plants

• Transitioning from a degree in political science to working in landscaping and pursuing landscape architecture

• Choosing to work manual labor jobs in Asheville to gain hands-on horticultural experience

• The importance of trusting your gut and following passion over societal expectations

• A serendipitous encounter in a restaurant that led to discovering Southern Highlands Reserve

• Driving up Toxaway Mountain for the first time and feeling an immediate connection to the site

• The founding story of Southern Highlands Reserve by Robert and Betty Balentine and how land once slated for development became a conservation easement

• Surveying the land to understand its ecological significance and formally establishing the Reserve

• Protecting spray cliff waterfall communities that would’ve been lost to development

• The significance of the endemic Rhododendron vaseyi (pink-shell azalea) population on the property

• The small team and key staff members that help maintain and grow the Reserve’s mission

• Projects focused on conserving plants of the Southern Blue Ridge and contributing to broader biodiversity goals

• Collaborating on wetland restoration in Great Smoky Mountains National Park and successful native plant propagation

• Partnering with Atlanta Botanical Garden to germinate Torreya taxifolia (Florida torreya) seeds using biochar, despite challenges with squirrels

• Biochar’s surprising success in aiding seed germination and growth in experimental trials

• Contributing to the Southern Appalachian Spruce Restoration Initiative (SASRI)

• The red spruce restoration work and growing tall plugs for underplanting in deciduous forests

• The unique relationship between flying squirrels and red spruce trees

• Observing a truffle firsthand while working with biologists on spruce habitat

• An overview of Kelly’s favorite parts of Southern Highlands Reserve

• Highlighting the Wildflower Labyrinth and pond garden room as especially meaningful and ecologically rich

• Advocating for careful observation of landscapes through different conditions as the foundation for conservation

• The design approach of “don’t mess it up” and “polish the stone” guiding garden development

• Gary Smith’s original design and support for adapting plantings in response to climate change

• How conservation is gardening and really observing a space

• Emphasizing the long-term nature of conservation and the importance of partnerships

• Personal experience transforming a yard from exotic invasives to native biodiversity

• The role home gardens and even green roofs can play in conservation efforts

• Seeing dramatic increases in biodiversity in her own yard after going chemical-free for eight years

• Explaining assisted migration as a response to climate change for isolated species

• Reflecting on a 2013 biodiversity survey that showed greater diversity in cultivated garden areas than surrounding wild areas

• How added water features and human care increased biodiversity in garden rooms

• Finding inspiration from nature

• Rebuilding after Hurricane Helene and observing its devastating effects on Western North Carolina

• The emotional toll of the storm and the human response to come together and support one another

• Partnering with US Forest Service to assess storm damage and plan targeted restoration efforts

• Managing stormwater as a critical concern in mountain environments and beyond

• Building a new greenhouse designed to increase red spruce production and improve visitor experience

• Installing extensive green infrastructure like rain gardens, bogs, and French drains to manage runoff

• The greenhouse project successfully withstanding Hurricane Helene's stormwater test

• Gratitude to funders and volunteers who made the greenhouse and other efforts possible

• Finding creative flow through hands-on gardening and spending time in the landscape

• Favorite go-to books Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians by Dennis Horn, Tavia Cathcart, Thomas Hemmerly, and David Duhl and Planting in a Post-Wild World by Thomas Rainer and Claudia West

• Dispelling the myth that everyone has the capacity to have a green thumb with the right mindset

• Excitement about a newly constructed mountain bog garden showcasing rare and endangered species

• Thoughts on how artists and gardeners are deeply connected through slow, creative processes

• How to propagate more gardeners and conservation by choosing connection, compassion, and curiosity over division

• You can learn more about Kelly and Southern Highlands Reserve by visiting their website and Instagram @southern_highlands_reserve.