ENVIRONMENT

Researchers have discovered that people who mow their lawns once every two weeks have more pollinating bees than people who mow their lawns every week. (Science)

Don’t have a lawn? You can still welcome bees with a simple-to-build bee hotel!

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

• One of our colleagues here at Nat Geo called this research a “Goldilocks” study. Why? Read the short Science article for some help.
  • In the most famous version of the fairy tale “Goldilocks and the Three Bears”, Goldilocks breaks into the home of a family of bears and tries three versions of different amenities (porridge, chairs, beds) before deciding on one that is “just right.”
  • In this study, researchers tried three versions of lawn-mowing schedules before finding one that was “just right” to attract helpful bees.

• Why do researchers think the bees preferred lawns that were mowed every other week, instead of those that were mowed every week?
  • Flowers! Between mowing, lawns sometimes bloom with “lawn flowers” like dandelions and clover. (Yes, lawn flowers may be more commonly known as “weeds.”) The two-week lawns had about 30% more lawn flowers than the one-week lawns.
    • Why flowers? Plants and pollinators have a mutualistic relationship. Flowering plants rely on bees and other pollinators to transfer pollen from one plant to another. Bees rely on nectar and pollen for nutrition.

• The three-week lawns had even more flowers than the two-week lawns. Why do researchers think bees still found the two-week lawn “just right”?
  • Scientists think bees found the three-week lawns “less attractive, because the taller grass might have made it more difficult for the bees to reach the flowers.”
    • The Goldilocks bees:
      • One week? Too few flowers.
      • Three weeks? Grass too tall.
      • Two weeks? JUST RIGHT.

• Does your family, community, or school have lawns that needs mowing? Mimic the research to see when bees are most active in your neighborhood! (This might be a good springtime Nat Geo Inquiry project!)
  • Find two or more lawns of similar size, or two or three sections of the same lawn.
  • Keep one lawn on its current mowing schedule. (This is your control lawn.)
  • Change the mowing schedule of the other lawn or lawns—mow more often or less often.
  • Keep track of the number and type of lawn flowers that bloom between mowing days. If you have a smart phone, use an app like iNaturalist to help you identify your flowers.
  • Monitor your lawns as often as you can, keeping track of the bees and other insects you find. Use tools like a net or an inexpensive aspirator to help trap and release insects. (We love this photo of a student using an aspirator to collect insects in Alaska!) If you have a smart phone, use an app like iNaturalist to help document the insects you find.
  • What flowers seem to attract the most insects?
  • What time of day seems to attract the most insects?
  • When were insects most active—days before mowing or after mowing?
  • What lawn (or section of lawn) attracted the most insects?

TEACHERS TOOLKIT

Science: Bees love the lawns of lazy homeowners

Nat Geo: Build Your Own Bee Hotel

(extra credit!) Biological Conservation: To mow or to mow less: Lawn mowing frequency affects bee abundance and diversity in suburban yards