1284: "Strawberries and Garlic are Companion Plants"

Interesting Things with JC #1284: "Strawberries and Garlic are Companion Plants" – They grow in silence, side by side, one sweet, one sharp. But together, strawberries and garlic create something nature alone couldn’t plan.

• Curriculum

  Episode Anchor

  Episode Title: Strawberries and Garlic
  Episode Number: #1284
  Host: JC
  Audience: Grades 9–12, college intro, homeschool, lifelong learners
  Subject Area: Biology, Environmental Science, Agriculture, History of Science

  Lesson Overview

  Students will:

  • Define the concept of companion planting and explain its biological basis.

  • Compare the growth patterns and root systems of garlic and strawberries.

  • Analyze historical evidence supporting the strawberry-garlic pairing from 19th and 20th century sources.

  • Explain how plant biochemistry can impact ecological pest control strategies.

  Key Vocabulary

  • Companion Planting (kuhm-PAN-yuhn PLAN-ting) — The strategic planting of different species together to benefit one or both. In this case, garlic protects strawberries from pests.

  • Allicin (AL-uh-sin) — A sulfur compound in garlic with antimicrobial and insect-repelling properties.

  • Root Profile (root PROH-file) — The direction and depth of a plant’s root system. Garlic grows deep, strawberries grow wide.

  • Powdery Mildew (POW-der-ee MIL-doo) — A fungal disease affecting strawberries that appears less frequently with garlic interplanting.

  • Micro-climate (MY-kroh-kly-mit) — A small area with its own climate conditions. Interplanting benefits are more noticeable in beds under 10 feet.

  Narrative Core

  • Open: The image of gardeners checking for signs of life in spring, whether strawberries or garlic.

  • Info: Companion planting isn’t folklore—it’s supported by chemistry and biology.

  • Details: Garlic releases protective sulfur compounds. Its deep root system complements the shallow-rooted strawberry. Their growth cycles and sun needs align.

  • Reflection: Historical practices from France, Germany, and WWII Poland support the technique. Modern organic growers see yield increases and reduced pests.

  • Closing: “These are interesting things, with JC.”

  Transcript

  See Transcript Below

  Student Worksheet

  1. What is companion planting, and how does it benefit strawberries and garlic?

  2. How do the root systems of garlic and strawberries complement each other?

  3. What chemical compound does garlic release that helps repel pests?

  4. Describe one historical example of garlic-strawberry interplanting.

  5. Why might this method still be used today by organic farmers?

  Teacher Guide

  • Estimated Time: 1–2 class periods (45–90 minutes)

  • Pre-Teaching Vocabulary Strategy:
    Use a Frayer Model to define allicin, companion planting, and root profile.

  • Anticipated Misconceptions:

    • Students may think plants compete for all resources.

    • Students may assume garlic is only useful for flavor, not pest control.

  • Discussion Prompts:

    • Why do you think farmers from over a century ago used this method without modern science?

    • Could companion planting replace chemical pesticides in modern agriculture?

  • Differentiation Strategies:

    • ESL: Use diagrams to show root systems and interplanting layouts.

    • IEP: Provide sentence starters for analysis questions.

    • Gifted: Ask students to research another companion plant pair and present findings.

  • Extension Activities:

    • Design a garden bed layout that uses companion planting principles.

    • Conduct a mock soil analysis comparing two plant pairings.

  • Cross-Curricular Connections:

    • Biology: Plant physiology, pest resistance.

    • History: Agricultural practices from WWII and 19th century Europe.

    • Chemistry: Organic compounds like allicin and their effects.

  Quiz

  Q1. What is the primary benefit of planting garlic near strawberries?
  A. It improves strawberry taste
  B. It deters pests and disease
  C. It shortens the growing season
  D. It changes the soil pH
  Answer: B

  Q2. What is the name of the sulfur compound in garlic that has pest-repelling properties?
  A. Cyanide
  B. Chlorophyll
  C. Allicin
  D. Fructose
  Answer: C

  Q3. How do the root systems of strawberries and garlic differ?
  A. Garlic spreads out; strawberries grow down
  B. Both have identical root systems
  C. Garlic grows deep; strawberries spread out
  D. Garlic roots are shallow and wide
  Answer: C

  Q4. What 19th-century source mentioned garlic and strawberry interplanting?
  A. British Royal Garden Guide
  B. Massachusetts Farmers Almanac
  C. French Wine Journal
  D. Eastern Europe Seed Catalog
  Answer: B

  Q5. What percent of surveyed organic farmers saw reduced pests with garlic interplanting?
  A. 50%
  B. 63%
  C. 93%
  D. 100%
  Answer: C

  Assessment

  1. Explain how garlic acts as a natural pesticide in a garden bed shared with strawberries.

  2. Compare the biological characteristics that make garlic and strawberries compatible companion plants.

  3–2–1 Rubric

  • 3 = Accurate, complete, thoughtful

  • 2 = Partial or missing detail

  • 1 = Inaccurate or vague

  Standards Alignment

  U.S. Standards

  • NGSS HS-LS2-6: Evaluate claims about group behavior on ecosystem stability — Companion planting as a biological interaction model.

  • NGSS HS-LS1-5: Use evidence to illustrate how plants use chemical processes to defend themselves.

  • CCSS.ELA-LITERACY.RST.9-10.1: Cite textual evidence to support analysis of scientific texts.

  • CCSS.ELA-LITERACY.WHST.9-12.2: Write explanatory texts using discipline-specific vocabulary and evidence.

  UK/International Equivalents

  • AQA GCSE Biology 4.5.1.1: Plant tissues and their functions – relevance to garlic and strawberry root systems.

  • IB MYP Sciences Criterion D: Reflecting on the impacts of science – explore historical and agricultural implications.

  • Cambridge IGCSE Biology 2.23: Understand adaptations for plant survival and mutual benefit.

• Transcript

  Interesting Things with JC #1284: "Strawberries and Garlic"

  There’s a moment every spring when gardeners bend low to the soil, brush away the mulch, and look for signs of life. Most are hunting for strawberries, those bright red, fragrant signals of early summer. But a quiet few are checking the garlic. And here’s the interesting part: some are checking both, in the same bed.

  For over a century, experienced growers have known something odd: strawberries and garlic grow better when planted together. In gardening terms, they’re what’s called companion plants. This isn’t folklore. It’s field-tested biology.

  Garlic, a bulb in the Allium sativum (AL-ee-um sah-TEE-vum) family, gives off strong sulfur compounds, particularly allicin. These compounds are antimicrobial, antifungal, and insect-repelling. They’re like a natural pesticide that doesn’t harm the plant, or the soil around it. When garlic grows near strawberries, those chemicals form a kind of scent barrier. Aphids, mites, and certain beetles are less likely to attack the strawberries. Powdery mildew and gray mold, two of the most destructive strawberry diseases, occur less frequently in test plots with garlic interplanting.

  It’s not just protection. There’s a deeper biological alignment. Garlic has a vertical root profile, long, narrow, and deep. Strawberries, by contrast, send out wide, shallow roots with runners. This means they’re not competing for the same nutrients. One goes down, the other spreads out. Their root systems occupy different soil zones. Water use? Compatible. Sunlight needs? Identical. Even planting schedules align, garlic goes in during the fall, strawberries in early spring. They coexist without crowding each other’s growth cycles.

  This method isn’t new. Documentation from 19th-century French and German agricultural bulletins, translated and reprinted in American horticulture journals, advised pairing strong-scented bulbs with fruit crops prone to pest damage. Strawberries and garlic appeared together as early as 1874 in a Massachusetts Farmers Almanac entry noting improved berry yield when garlic was "cluster-planted along the northern rows." And it wasn’t just in the U.S. In Poland (POH-land) and parts of Eastern Europe, wartime gardening guides from World War II included companion pairings as a way to maximize food reliability without chemical sprays. Garlic and strawberries showed up again and again.

  Today, modern organic growers in Vermont, Oregon, and the Carolinas still use this method. It’s quiet, it’s efficient, and it works, especially in beds under 10 feet (3 meters) long where micro-climates make pest control tricky. One organic farming survey from 2008 tracked 48 growers across five states. Of those using companion strategies, 93% reported fewer insect issues in beds where garlic or onions bordered their strawberries. Yield didn’t just hold, it increased, sometimes by as much as 20%.

  Now, if you plant garlic with strawberries, your neighbors might think you’ve made a mistake. Garlic doesn’t look like it belongs in a fruit bed. But that’s exactly why it does. It holds the line. Quietly. Underground.

  And maybe that’s the legacy of this strange pairing. It’s not flashy. There’s no giant harvest festival for the unsung garlic bulb that protected the strawberries from rot. But it did its job. It still does. And if you’re ever tempted to see gardening as simple, this one pairing reminds us that the smartest solutions aren’t always the most obvious.

  These are interesting things, with JC.

• Show Notes

  In this episode, JC explores a surprising agricultural insight: strawberries and garlic thrive when planted together. This companion planting method isn't just practical—it’s grounded in chemistry, biology, and centuries of cross-cultural agricultural knowledge. Teachers and students can use this topic to connect plant biology with environmental science and history, highlighting how simple, sustainable techniques can outlast modern interventions. This episode brings real-world relevance to botanical science and ecological agriculture.

  Reference:

  Gardening Know How. (n.d.). Strawberry companion plants – What to grow with strawberries. Gardening Know How. https://www.gardeningknowhow.com/edible/fruits/strawberry/strawberry-companion-plants.htm