Do not plant cucurbits in ground that held cucurbits within 2-3 years.
As recorded: Do not plant Cucurbitaceae in ground that held Cucurbitaceae within 2-3 years.
Promising A person has checked it against its sources. If you skip this, you lose real yield. The planner warns you.
How it works
Melittia cucurbitae overwinters as a pupa in the soil where its host grew and emerges the next summer; Anasa tristis overwinters as an adult in sheltered sites (plant debris, under boards or rocks) and flies to cucurbits in spring. A host-free break cuts local carryover, but both are strong fliers that re-invade from a distance, so rotation is only partial and works best paired with fall sanitation (destroy spent vines).
What to do about it
Plant cucurbits in different ground, or wait 3 years. Destroy the spent vines in autumn and clear debris and boards nearby. The pupae overwinter in the soil where the crop grew, the adults in the shelter around it. Rotation is only partial; both pests fly in from a distance.
How much it matters: Extension guidance is to alternate seasons / rotate away and destroy crop residue; rotation alone is partial because adults fly in (SVB from as far as several miles). The 2-3 year interval is Cornell's rotation for cucurbit diseases (the last pointer); no source states it as a pest threshold.
The evidence
Evidence: checked against 4 sources in the research-based literature.
The 4 sources
… squash vine borers spend the winter in the soil near their host plants ... Practice rotation ... planting cucurbits in different areas of your garden if possible, or alternate seasons
Crop rotation away from previously infested fields helps reduce local populations, as overwintering pupae remain in the soil. However ... fields often need to be rotated more than 5 miles away as SVB can fly into fields from long distances.
Squash bugs can live through the winter as adults in sheltered places, such as under plant debris, around buildings, or under rocks. When adults come out in the spring, they fly to growing cucurbit plants.
… 2+ years; avoid other cucurbits
Plants it applies to · 7
Folklore it answers
Read next
- Do you need to rotate crops in a raised bed?Yes. The pests and diseases live in the soil, so a raised bed needs rotating like any ground. Here's why, and why digging out the soil is the costly way to do the same job.
- Crop rotation for the home gardenMove crops by plant family so soil-borne pests and diseases can't settle in. What to rotate, how far apart, and what rotation can and can't do.
- Growing cucumbers on a trellisCucumbers grow fine on the ground and better up a trellis, with straighter fruit in less space. Vining or bush, why you pick daily, and why a bitter one is stressed.
How this rule has changed
Every change is dated, newest first. The full record, with each reason, is in the data download.
- Sources updated
- Sources updated
- Sources updated
- Wording made clearer
- Advice on what to do added
- A person read the sources and confirmed it
- Added to the rules
You must rotate every crop to new ground every single year. · What can I plant now?
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Cite this page
Milpa Gardens. “Do not plant cucurbits in ground that held cucurbits within 2-3 years.” Evidence grade: Promising. https://milpa.garden/rules/do-not-plant-cucurbits-ground-that-held/
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- 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.
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- The evidence points both ways, or no study has tested it, so the planner does not enforce it.
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