A bed whose shorter side runs well past ~1.2 m has interior ground that can't be reached from its edges.
Promising · suboptimal if ignored → advise
How it works
A comfortable arm's reach is ~0.6 m, so ground more than twice that across can only be tended by standing on the bed — which compacts the soil and breaks the structure the bed exists to protect.
What to do about it
Make a wide area into several beds with a path between them, not one bed you step into. Beds are individual entities here — there is no sub-bed to carve, so add another bed instead.
The evidence
Evidence: confirmed against 3 sources in the research-based literature.
the 3 sources
Iowa State Univ. Extension, Yard & Garden FAQ, raised bed size (read 2026-07-21; read by the maintainer 2026-07-25): 'Beds accessible on both sides can be 3 to 4 feet wide'; one-sided, 'the maximum width should be 1 1/2 to 2 feet (i.e., approximately arm's reach)'.
Univ. of Minnesota Extension, Raised bed gardens (read 2026-07-21; read by the maintainer 2026-07-25): 'the reach of your arm is generally a good metric ... If you can access both sides, the bed can be up to five feet wide.'
The two sources DISAGREE on the ceiling - Iowa State's 3-4 ft against Minnesota's 5 ft - and this rule takes the tighter one. Which source to take is a judgement, which is why this is recorded as promising rather than well established. AMENDED 2026-08-21: the threshold was first recorded as 120 cm, a metric rounding that fell 2 cm short of Iowa State's own 4-ft ceiling - so the single most common raised-bed size (a 4x4, 121.9 cm) tripped the reach warning and the another rule here strip split. The maintainer's 4x4 report caught it. Now 122 cm, exactly the tighter source's stated ceiling: a number the source does state.
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- another rule here: reach threshold 120 -> 122 cm, the source's own 4-ft ceiling
- say the grade in the app's words, not the corpus's letter
- Corpus: another rule here verified - the maintainer read the raised-bed width sources
- corpus: add another rule here — a bed too wide to reach into (Promising, advise)
Cite this page
Milpa Gardens. "A bed whose shorter side runs well past ~1.2 m has interior ground that can't be reached from its edges." Evidence grade: Promising. https://milpa.garden/rules/bed-whose-shorter-side-runs-well-past/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.