351 episodes
Organic, Conventional, or Homegrown: What the Research Really Shows About Nutrition - Ep. 313
08/11/2026 | 31 mins.You've probably heard both sides of this argument: that organic and conventional produce are nutritionally identical, and that homegrown vegetables blow store-bought out of the water. Which one is true?
In this episode, I dig through the peer-reviewed research on three separate questions: whether organic farming produces more nutritious food, whether soil health itself changes the nutrient content of what we eat, and what happens to those nutrients in the days between harvest and the moment food lands on your plate. I'm treating this as a real meta-analysis, pulling together findings from major systematic reviews, long-term field trials, and postharvest storage studies, and following the data wherever it leads.
The answer is more interesting, and more useful for your own garden, than either side of the argument usually admits. By the end, you'll know exactly which parts of the nutrient-density conversation hold up under scrutiny and which parts are oversimplified, plus what it means for the food coming out of your own backyard.
Let's dig in!
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Peer-Reviewed Sources
Smith-Spangler et al. (2012), Annals of Internal Medicine — Are Organic Foods Safer or Healthier Than Conventional Alternatives?: https://www.acpjournals.org/doi/10.7326/0003-4819-157-5-201209040-00007
Baranski et al. (2014), British Journal of Nutrition — Higher Antioxidant and Lower Cadmium Concentrations in Organically Grown Crops (343-study meta-analysis): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141693/
Worthington (2001), Journal of Alternative and Complementary Medicine — Nutritional Quality of Organic Versus Conventional Fruits, Vegetables, and Grains: https://pubmed.ncbi.nlm.nih.gov/11327522/
Hunter et al. (2011), Critical Reviews in Food Science and Nutrition — Evaluation of the Micronutrient Composition of Plant Foods Produced by Organic and Conventional Methods: https://pubmed.ncbi.nlm.nih.gov/21929333/
Montgomery & Biklé (2021), Frontiers in Sustainable Food Systems — Soil Health and Nutrient Density: Beyond Organic vs. Conventional Farming: https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2021.699147/full
Lehmann et al. (2014), Soil Biology and Biochemistry — Arbuscular Mycorrhizal Influence on Zinc Nutrition in Crop Plants: A Meta-Analysis: https://www.sciencedirect.com/science/article/abs/pii/S0038071713004045
Reganold et al. (2010), PLOS ONE — Fruit and Soil Quality of Organic and Conventional Strawberry Agroecosystems: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0012346
Helfenstein et al. (2016), PLOS ONE — Organic Wheat Farming Improves Grain Zinc Concentration: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160729
Hepperly, Omondi & Seidel (2018), MOJ Food Processing & Technology — Soil Regeneration Increases Crop Nutrients, Antioxidants and Adaptive Responses (Rodale Institute Farming Systems Trial): https://medcraveonline.com/MOJFPT/soil-regeneration-increases-crop-nutrients-antioxidants-and-adaptive-responses.html
Davis, Epp & Riordan (2004), Journal of the American College of Nutrition — Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999: https://pubmed.ncbi.nlm.nih.gov/15637215/
Marles (2017), Journal of Food Composition and Analysis — Mineral Nutrient Composition of Vegetables, Fruits and Grains: The Context of Reports of Apparent Historical Declines: https://www.sciencedirect.com/science/article/pii/S0889157516302113
Favell (1998), Food Chemistry — A Comparison of the Vitamin C Content of Fresh and Frozen Vegetables: https://www.sciencedirect.com/science/article/abs/pii/S0308814697001659
Rickman, Barrett & Bruhn (2007), Journal of the Science of Food and Agriculture — Nutritional Comparison of Fresh, Frozen and Canned Fruits and Vegetables, Part 1: https://scijournals.onlinelibrary.wiley.com/doi/abs/10.1002/jsfa.2825
Li, Pegg, Eitenmiller, Chun & Kerrihard (2017), Journal of Food Composition and Analysis — Selected Nutrient Analyses of Fresh, Fresh-Stored, and Frozen Fruits and Vegetables: https://www.sciencedirect.com/science/article/abs/pii/S0889157517300418
Galani et al. (2017), Antioxidants — Storage of Fruits and Vegetables in Refrigerator Increases Their Phenolic Acids but Decreases the Total Phenolics, Anthocyanins and Vitamin C: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5618087/
Jo, Shin & Lee (2003), Journal of Agricultural and Food Chemistry — The Effect of Post-Harvest and Packaging Treatments on Glucoraphanin Concentration in Broccoli: https://pubs.acs.org/doi/10.1021/jf0203592
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In this episode, we're pulling back the curtain on the Cooperative Extension System: where it came from, starting with farmers comparing notes in the early 1800s, through the Morrill Act's creation of land-grant universities in 1862, the Hatch Act's 1887 research mandate, and the 1914 Smith-Lever Act that built the nationwide Extension system we know today.
We'll also trace the Master Gardener program from its 1972 origins in Washington State and we'll get honest about reliability: how peer review works (and where it doesn't), how to evaluate a publication for yourself, and why regional, research-based information matters more than ever in an age of viral gardening myths.
This one's less about your garden bed and more about why you can trust what I tell you to put in it. Let’s dig in!
Episode References
https://LarrysCoffee.com/JustGrow – Free Gift with order from this link only!
Battling Blossom End Rot the Right Way - Ep. 309
Raised Bed Gardening with Gardener Scott - Ep. 268
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Resources
Rutgers Cooperative Extension — The 1914 Smith-Lever Act: https://extension.rutgers.edu/history/smith-lever
OSU Extension — A Brief History of Extension: https://extension.osu.edu/about/mission-vision-values/osu-extension-brief-history
USDA NIFA — History: https://www.nifa.usda.gov/about-nifa/who-we-are/history
USDA NIFA — Cooperative Extension History: https://www.nifa.usda.gov/about-nifa/what-we-do/extension/cooperative-extension-history
USDA NIFA — What We Do: Extension: https://www.nifa.usda.gov/about-nifa/what-we-do/extension
gov CRS — The Agricultural Cooperative Extension System: An Overview: https://www.congress.gov/crs-product/R48071
gov CRS — The U.S. Land-Grant University System: https://www.congress.gov/crs-product/R45897
APLU — Land-Grant University FAQ: https://www.aplu.org/about-us/history-of-aplu/what-is-a-land-grant-university/
Land-Grant Impacts — Extension (current office count): https://landgrantimpacts.org/extension/
Garden Professors — Not All Extension Publications Are Created Equal: https://gardenprofessors.com/not-all-extension-publications-are-created-equal/
OSU Extension — Peer Review Guidelines: https://extension.oregonstate.edu/peer-review-guidelines
University of Illinois Extension — Peer Reviewed Publications: https://extension.illinois.edu/global/peer-reviewed-publications
Clemson News — Land-Grant Press Publications: https://news.clemson.edu/land-grant-press-publications-provide-vital-knowledge-from-clemson-cooperative-extension-program-areas/
Washington State University — History of the Master Gardener Program: https://mastergardener.wsu.edu/who-we-are/history/history-of-the-master-gardener-program/
WSU CAHNRS News — Seeds of a Movement: 50 Years Ago: https://news.cahnrs.wsu.edu/article/seeds-of-a-movement-50-years-ago-master-gardeners-began-with-wsu-trained-volunteers/
University of Missouri Extension — History of Extension: https://extension.missouri.edu/about-us/history-of-extension
Master Gardeners of Greene County — History (Missouri program): https://mggreene.org/history/
University of Missouri Extension — Extension Master Gardener Program: https://extension.missouri.edu/programs/extension-master-gardener
OSU Extension — Experts Debunk 10 Common Gardening Myths: https://extension.oregonstate.edu/news/osu-extension-experts-debunk-10-common-gardening-myths
University of Arkansas ScholarWorks — Social Media Misinformation Among Extension Educators (dissertation): https://scholarworks.uark.edu/etd/5861/
Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising. The Science We Got Wrong: How Plant Research Rewrote the Rules for Gardening - Ep. 311
07/28/2026 | 41 mins.For most of the last century, gardeners were taught to cultivate their soil after every rain to conserve moisture, to think of plant roots as lone competitors, and to treat "plant communication" as science fiction. All of that was built on the best evidence available at the time, and all of it has been revised, in some cases more than once, as better tools let researchers see what earlier generations simply could not. In this episode, we walk through four real case studies of plant science changing its mind. Along the way, we talk about how the scientific method works, why one of my favorite phrases, "we don't know what we don't know," is not a discouraging idea but an exciting one, and what all of this means for the choices you make in your own garden each season, now and into the future.
Let’s dig in!
References and Resources:
Chalker-Scott, L., and C.H. Daniels. (2016). "Scientific Literacy for the Citizen Scientist." WSU Extension Manual EM100E. https://wpcdn.web.wsu.edu/extension/uploads/sites/30/2024/07/Scientific-Literacy-for-the-Citizen-Scientist.pdf
Chalker-Scott, L. (2021, revised). "Dust Mulch Efficacy in Gardens and Landscapes." WSU Extension Fact Sheet FS167E. https://wpcdn.web.wsu.edu/wp-ecommerce/uploads/sites/2/product-3540-sku-FS167E.pdf
Chalker-Scott, L. (2017). "A Gardener's Primer to Mycorrhizae: Understanding How They Work and Learning How to Protect Them." WSU Extension Fact Sheet FS269E. https://wpcdn.web.wsu.edu/wp-ecommerce/uploads/sites/2/product-3286-sku-FS269E.pdf
Chalker-Scott, L. (2023). "Gardening with Companion Plants." WSU Extension Publication EM128E. https://pubs.extension.wsu.edu/product/gardening-with-companion-plants-home-garden-series/
Oklahoma State University Extension. "Mycorrhizal Fungi." Fact Sheet. https://extension.okstate.edu/fact-sheets/mycorrhizal-fungi
Pacific Horticulture Society. "Mycorrhizal Fungi, Nature's Key to Plant Survival and Success." https://pacifichorticulture.org/articles/mycorrhizal-fungi-natures-key-to-plant-survival-and-success/
Cao, D., Chabikwa, T., Barbier, F., Dun, E.A., Fichtner, F., Dong, L., Kerr, S.C., & Beveridge, C.A. (2023). "Auxin-independent effects of apical dominance induce changes in phytohormones correlated with bud outgrowth." Plant Physiology, 192(2), 1420–1434. https://doi.org/10.1093/plphys/kiad034
Mason, M.G., Ross, J.J., Babst, B.A., Wienclaw, B.N., & Beveridge, C.A. (2014). "Sugar demand, not auxin, is the initial regulator of apical dominance." Proceedings of the National Academy of Sciences, 111(16), 6092–6097. https://www.pnas.org/doi/10.1073/pnas.1322045111
Barbier, F.F., Dun, E.A., & Beveridge, C.A. (2017). "A Growing Stem Inhibits Bud Outgrowth — The Overlooked Theory of Apical Dominance." Frontiers in Plant Science, 8:1874. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5671643/
"Lessons from a century of apical dominance research." (2023). Journal of Experimental Botany. https://pmc.ncbi.nlm.nih.gov/articles/PMC10400159/
Simard, S.W., Perry, D.A., Jones, M.D., Myrold, D.D., Durall, D.M., & Molina, R. (1997). "Net transfer of carbon between ectomycorrhizal tree species in the field." Nature, 388, 579–582. https://www.nature.com/articles/41557
"Belowground carbon transfer across mycorrhizal networks among trees: Facts, not fantasy." (2023). Review discussing the scope and limits of current evidence for mycorrhizal carbon transfer. https://pmc.ncbi.nlm.nih.gov/articles/PMC10751480/
Baldwin, I.T., & Schultz, J.C. (1983). "Rapid Changes in Tree Leaf Chemistry Induced by Damage: Evidence for Communication Between Plants." Science, 221(4607), 277–279. https://www.science.org/doi/10.1126/science.221.4607.277
Heil, M. (2014). "Herbivore-induced plant volatiles: targets, perception and unanswered questions." New Phytologist, 204(2), 297–306. https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.12977
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Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.- Your garden is at its busiest in July, and so is the wear and tear on your soil. In this episode we get past the fertilizer conversation and into whether your soil is still functioning at all — how traffic, pounding rain, heat, and heavy-feeding crops degrade soil mid-season, the physical, chemical, and biological warning signs to look for right now, and tests you can run this week to sort the problems. Plus, how to use a mid-season open bed as a soil-building opportunity.
Let's dig in!
REFERENCES & RESOURCES
University of Delaware Cooperative Extension — "Combating Soil Compaction" — https://www.udel.edu/academics/colleges/canr/cooperative-extension/fact-sheets/combating-soil-compaction/
University of Minnesota Extension — "Backyard science: Is your soil healthy?" (slake test, infiltration test, earthworm counts) — https://extension.umn.edu/yard-and-garden-news/backyard-science-your-soil-healthy
Cornell Soil Health Laboratory — Individual soil analyses, including wet aggregate stability — https://soilhealthlab.cals.cornell.edu/testing-services/individual-soil-analyses/
Purdue University Vegetable Crops Hotline — "Nitrogen Loss from Wet Soils" — https://vegcropshotline.org/article/nitrogen-loss-from-wet-soils/
UF/IFAS Extension — CIR 1092/SS117, "Soil and Container Media Electrical Conductivity Interpretations" — https://ask.ifas.ufl.edu/publication/SS117
Texas A&M AgriLife, Aggie Horticulture — "Salt Injury" (Cucurbit Problem Solver) — https://aggie-horticulture.tamu.edu/vegetable/problem-solvers/cucurbit-problem-solver/leaf-disorders/salt-injury/
Purdue University Vegetable Crops Hotline — "Summer Cover Crops for Improved Soil Health and Weed Management" — https://vegcropshotline.org/article/summer-cover-crops-for-improved-soil-health-and-weed-management/
Just Grow Something: https://justgrowsomething.com
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Feed my coffee habit: https://buymeacoffee.com/justgrowsomething
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Get 10% off and FREE shipping on my favorite raised planters at Planter Box Direct using code JUSTGROW10: https://planterboxdirect.com/?ref=593
Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising. - If you've grown tomatoes or peppers for more than one season, you more than likely know the feeling been waiting that first tomato to ripen, finally see it’s blushing red, and you flip it over to find a sunken, leathery patch covering half the bottom of the fruit. And if you went looking for answers, you probably found three of them repeated everywhere you turned: sprinkle in some crushed eggshells, spray on some calcium, add a scoop of Epsom salt. All three of those are extremely common advice. Two of them do close to nothing. And one of them can genuinely make the problem worse.
That problem? Blossom end rot. Today on Just Grow Something we're covering what blossom end rot really is at the cellular level, the conditions that trigger it in your garden, why the most popular home remedies for it are built on a total misunderstanding of the problem, and what the research consistently recommends instead.
Let's dig in.
University Extension and Research-Based Resources
Utah State University Extension — Blossom End Rot (IPM Fact Sheet) https://extension.usu.edu/planthealth/ipm/notes_ag/veg-blossom-end-rot
Purdue Extension — Blossom End Rot of Tomato Fruit (BP-13-W) https://www.extension.purdue.edu/extmedia/bp/bp-13-w.html
University of Maryland Extension — Blossom End Rot on Vegetables https://extension.umd.edu/resource/blossom-end-rot-vegetables
Alabama Cooperative Extension System — Blossom-End Rot in Tomatoes: Causes and Prevention (ANR-1059) https://www.aces.edu/blog/topics/lawn-garden/blossom-end-rot-in-tomatoes-causes-and-prevention/
University of Massachusetts Amherst, Center for Agriculture, Food, and the Environment — Solanaceous: Blossom End Rot https://ag.umass.edu/vegetable/fact-sheets/solanaceous-blossom-end-rot
Oregon State University Extension — Blossom-End Rot of Tomatoes (FS-139) https://extension.oregonstate.edu/catalog/fs-139-blossom-end-rot-tomatoes
University of Wisconsin Horticulture Extension — Blossom End Rot https://hort.extension.wisc.edu/articles/blossom-end-rot/
University of California Cooperative Extension, UC ANR "The Real Dirt" — Fighting Blossom End Rot https://ucanr.edu/blog/real-dirt/article/fighting-blossom-end-rot
University of Connecticut Extension — Put an End to Blossom-End Rot: Water and Nutrient Management is Key https://homegarden.cahnr.uconn.edu/2025/06/15/blossom-end-rot/
Clemson Cooperative Extension HGIC — Gardening Myths: Fix Blossom End Rot with Calcium Sprays https://hgic.clemson.edu/gardening-myths-fix-blossom-end-rot-with-calcium-sprays/
North Dakota State University Extension — The Epsom Salt Myth https://www.ndsu.edu/agriculture/extension/extension-topics/gardening-and-horticulture/vegetables/epsom-salt-myth
University of Minnesota Extension — Do Common Soil Health "Home Remedies" Work? (Coffee Grounds, Eggshells, Epsom Salts) https://extension.umn.edu/manage-soil-nutrients/coffee-grounds-eggshells-epsom-salts
Peer-Reviewed Research
Topcu, Y., Nambeesan, S. U., & van der Knaap, E. (2022). Blossom-end rot: a century-old problem in tomato (Solanum lycopersicum L.) and other vegetables. Molecular Horticulture, 2, 1. https://doi.org/10.1186/s43897-021-00022-9
Just Grow Something: https://justgrowsomething.com
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Check out how you can become a patron on Patreon: https://www.patreon.com/JustGrowSomething
Feed my coffee habit: https://buymeacoffee.com/justgrowsomething
Amazon storefront: https://www.amazon.com/shop/justgrowsomething
Get 10% off and FREE shipping on my favorite raised planters at Planter Box Direct using code JUSTGROW10: https://planterboxdirect.com/?ref=593
Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.
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About Just Grow Something | Evidence-Based Home Gardening
Grow a better vegetable garden, whether you're a seasoned gardener or have never grown a thing in your life. Karin helps home gardeners learn to grow their own food using evidence-based techniques and research. She talks all about specific plants, pests, diseases, soil and plant health, mulch, garden planning, and more. It's not just the "how" but also the "why" that makes us better. The goal? For everyone to know how to grow their own food no matter what sized space they have or their experience level.
Tune in each week to plan, learn, and grow with your friend in the garden, Karin Velez.
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