Fennel may hold back neighboring vegetables with chemicals it releases
Fennel may hold back neighboring vegetables with chemicals it releases. The evidence is thin, from lab tests mostly on weeds.
As recorded: Fennel is allelopathic; a suppressive effect on neighboring vegetables is plausible but poorly characterized (evidence is weed-directed, in vitro).
A good hunch If you skip this, it still grows, just less well. The planner suggests it.
How it works
Reported allelopathic exudates. Effect size poorly characterized.
The evidence
Evidence: checked against 2 sources in the research-based literature.
The 2 sources
Plus one working note on how the sources were read. Every note is in the data download.
Plants it applies to
How this rule has changed
Every change is dated, newest first. The full record, with each reason, is in the data download.
- Details updated
- Wording made clearer
- Wording made clearer
- Wording made clearer
- A person read the sources and confirmed it
- Wording made clearer
- Added to the rules
Cite this page
Milpa Gardens. "Fennel may hold back neighboring vegetables with chemicals it releases. The evidence is thin, from lab tests mostly on weeds." Evidence grade: A good hunch. https://milpa.garden/rules/fennel-allelopathic-suppressive-effect-neighboring-vegetables-plausible/
A garden planner built on graded evidence. 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.
How we grade evidence
- Well established
- The rule names its mechanism and is settled, by sources a person has read and checked or by plain arithmetic and geometry.
- Promising
- The mechanism is named and the literature backs it. A few questions are still open.
- A good hunch
- Plausible by its mechanism, but field studies are thin, so treat it as a lean.
- Contested
- The evidence points both ways, or no study has tested it, so the planner does not enforce it.
- Refuted
- The claim did not survive its sources. It is kept so the folklore can be answered.