LUKE DAHLBERG BIO
With over twenty years of experience in propagating midwestern native plants, Luke Dahlberg turned his passionate backyard hobby into a career. Luke earned his degree majoring in Ornamental Horticulture and a minor in Business from the University of Wisconsin - Platteville. After working in the commercial nursery trade for several years, Luke landed his current position as Conservation Seed Program Manager at Citizens for Conservation, an organization that he started volunteering at in 2004 and became part of the organization's staff in 2018 where he continues CFC's mission of restoring and educating others about the ecosystems of the Chicago area. Collaborating with Lake County Forest Preserves, Luke was able to use their greenhouse to propagate rare native plants and learn from germination trials the best practices to use to reintroduce them into the wild in preserved plant communities. Luke loves to share what he has learned in plant propagation with others through his Instagram page, and has had opportunities to speak at the Wild Things Conference in Chicago, teach native plant propagation classes at The Morton Arboretum, and speak at a TEDx event and posts on the Grassland Restoration Network blog. In his spare time, Luke enjoys photographing birds and wildflowers and spending time with friends and his family.
You can learn more from Luke by visiting his Instagram page @seedtech_luke and Citizens for Conservation at citizensforconservation.org.
SHOW NOTES
Growing up in the west suburbs of Chicago near Lombard, which has one of the largest lilac collections in the country
Starting with nature at age five by germinating dandelion seeds in a coffee tin
Being the kid with subscriptions to both Birds and Blooms Magazine and Nintendo Power Magazine
Learning about prairies in fifth grade despite growing up in Illinois, the prairie state
Field guides coming to life when discovering native plants like Asclepias incarnata (swamp milkweed) and Andropogon gerardii (big bluestem) near fishing ponds
Meeting mentor Tom Vanderpool at Citizens for Conservation plant sale as a middle schooler
Being given special seed collecting missions during volunteer workdays, feeling like "special ops"
Discovering Prairie Moon Nursery and William Cullina's native plant propagation book series
Working at Morton Arboretum during summers and falling in love with their "conservation through cultivation" principle
Getting disillusioned with commercial nursery work due to chemical use and lack of passion for common cultivars
Returning to Citizens for Conservation after mentor Tom's death and getting laid off in 2017
Six years at Lake County Forest Preserve seed nursery focusing on rare plants rather than aesthetics
Citizens for Conservation being 54 years old, starting with recycling and land conservation in the 1970s
The impact of 99.9% of tallgrass prairie in Illinois being destroyed
Railroad companies historically throwing burning coals to control brush, inadvertently preserving prairie remnants
Collecting over 200 species from railroad right-of-ways within a 30-mile radius for hyper-local ecotype preservation
Modern railroad herbicide use destroying the plant communities that were preserved for decades
Citizens for Conservation being volunteer-founded and volunteer-run with a servant leadership mindset
Educational programs including taking fourth and second graders to prairies and hosting native plant sales
Seed collecting starting in mid-winter with planning and note-taking throughout the year
Plants taking four to eight weeks from pollination to seed depending on species
Spring ephemerals being the most critical to collect because they don't hold seeds as long
Sanguinaria canadensis (bloodroot) flowers lasting only one to three days with an extremely narrow collection window
Fall collection season running from mid-August to early November, from bulrushes to asters and goldenrod, and some plants like Amorpha canescens (leadplant) and Ratibida pinnata (gray-headed coneflower) hanging on until Christmas
Using photos and Excel spreadsheets to track bloom times and seed collection over five-year periods
Looking for color changes from green to brown and feeling for firmness in seed capsules
Checking with local agencies about legal seed collection and avoiding private property
Collecting only about 50% of available seed to ensure wild plant survival
Orthodox seeds being able to dry out versus recalcitrant seeds needing high moisture content
Seeds being living things with embryos, endosperm, seed coats, and sometimes pericarps
Bloodroot being ant-dispersed with elaiosomes that ants eat before discarding seeds in nutrient-rich waste areas
Stratification being seed conditioning involving temperature, moisture, and time combinations
Cold stratification periods varying from 30 days in the south to 90-120 days in the Chicago region
Some plants like trillium and Panax quinquefolius (ginseng) requiring up to two years of stratification cycles
Discovering boiling water scarification for Baptisia after observing post-fire germination and how hot water treatment at 180–200°F causes baptisia seeds to double in size overnight
Using natural temperature fluctuations in unheated sheds rather than controlled refrigeration to improve germination
Sedges being diverse in germination requirements with some needing cross-pollination between populations
Fern spore collection using wax paper to create beautiful imprints overnight
Growing ferns requiring sterile conditions, distilled water, and careful temperature management
Triosteum (horse gentian) being extremely difficult to germinate
Successfully growing Lithospermum canescens (hoary puccoon) and Calystegia spithamaea (low bindweed) after multiple attempts
Wood betony being a hemiparasitic plant used to control aggressive goldenrod in restorations
Hemiparasites using haustoria to tap into host plants while retaining photosynthetic ability
Growing wood betony with grass and sedge hosts rather than forbs to avoid competition
Sowing hemiparasite seeds directly with hosts for best attachment during germination
Using Cuscuta (dodder) to achieve 90% reduction in Helianthus grosseserratus (sawtooth sunflower) monocultures
Book recommendations including William Cullina's The New England Wild Flower Society Guide to Growing and Propagating Wildflowers of the United States and Canada, Ken Druse’s Making More Plants, The Living Landscape: Designing for Beauty and Biodiversity in the Home Garden by Rick Darke and Doug Tallamy, A Sand County Almanac by Aldo Leopold, and Braiding Sweetgrass by Robin Wall Kimmerer
Breaking myths about seed sowing
Everyone being able to do conservation through cultivation, even with just one or two native plants
Building community and getting children into nature to spark curiosity and love of plants
You can learn more from Luke by visiting his Instagram page @seedtech_luke and Citizens for Conservation at citizensforconservation.org.