Rotation Break
A restorative break - planted to give the ground back what a rotation took.
Space it needs
At least 0.3 m². A bed smaller than that does not get this guild quietly substituted for something else — the planner greys it out, says why, and offers the nearest adaptation that does fit.
Between seasons
Nothing is left living in the bed over winter; the whole planting is re-established.
What it claims
residue mineralizes N for next season's crop
Promising
Mechanism: Residue decomposition mineralizes fixed N.
Evidence: confirmed against 2 sources in the research-based literature.
the 2 sources
Penn State Extension, 'Growing Cover Crops for Nitrogen on Vegetable Farms', extension.psu.edu/growing-cover-crops-for-nitrogen-on-vegetable-farms (read 2026-07-11): 'When cover crops are killed and begin to decompose, nitrogen can be released from the residues back into the soil where it can feed the next crop'; 'Mineralization is the process where organic nitrogen, which is largely not available to plants, is converted by soil microorganisms' into a plant-available form.
Univ. of Wisconsin-Madison Extension (Crops & Soils), 'Late Summer Planting Legumes to Produce Nitrogen Credits for Next Year', cropsandsoils.extension.wisc.edu/articles/late-summer-planting-legumes-to-produce-nitrogen-credits-for-next-year (read 2026-07-11): 'The nitrogen credit depends on the amount of crop growth and when the legume was planted. Nitrogen credits are 50 lb N/a lower on sandy, coarse-textured soils.'
low rotation pressure; occupies ground through the off-season
A good hunch
Mechanism: They host none of the big-three families' soilborne pathogens, so following those crops with an allium or apiaceous crop breaks the host cycle. But they are not inherently low-pressure: allium white rot (Sclerotium cepivorum) is allium-specific, its sclerotia persist 15+ years, and it cannot be eradicated once established; apiaceous crops carry their own soilborne diseases.
Evidence: confirmed against 1 source in the research-based literature.
the source
UMass Extension, 'Alliums, White Rot', ag.umass.edu/vegetable/fact-sheets/alliums-white-rot (read 2026-07-11): 'Sclerotium cepivorum is specific to allium species'; sclerotia 'may remain viable in soil for 15 years or more without allium hosts'; 'Currently, there is no way to eradicate white rot from a field where it has become established.'
Roles
A role is filled by whatever satisfies its predicate, not by a fixed species list. The canonical filler is the default; the alternatives are priced.
Fixer
Overwinter
What it costs the ground
Rotation history attaches to the ground, not the bed, so this is what the planner remembers about this patch after the guild comes out.
- Legumes: full load
- Alliums: partial load
All guilds