A border of a more attractive cucurbit (blue hubbard
A border of a more attractive cucurbit (blue hubbard, a winter squash), planted a week or two before the crop and kept unbroken around it draws striped cucumber beetles to the edge, where they are dealt with, so most of the beetles, and the bacterial wilt they carry, never reach the cucumbers, melons or summer squash inside.
As recorded: A border of a more attractive cucurbit (blue hubbard, a Cucurbita maxima), planted a week or two before the crop and kept unbroken around it draws striped cucumber beetles to the edge, where they are dealt with, so most of the beetles, and the bacterial wilt they carry, never reach the cucumbers, melons or summer squash inside.
Promising A person has checked it against its sources. If you skip this, it still grows, just less well. The planner suggests it.
How it works
Striped cucumber beetles prefer Cucurbita maxima to C. pepo and C. moschata, and they arrive in one early flush from whatever direction they overwintered. A perimeter of the preferred host intercepts that flush on every side and concentrates the beetles on plants the gardener can treat or strip, so the unsprayed center sees far fewer beetles and far less of the wilt bacterium they transmit. The trap concentrates the beetles and does not kill them. The beetles in the border must be removed, or the ring feeds the crop instead of protecting it.
What to do about it
Plant hubbard a week or two ahead of the crop in an unbroken ring around it, at no wider than the crop's own row spacing. Check the ring when the beetles arrive and deal with them there, by hand, under a cover, or with whatever control you choose. Keep checking the center. Do not use a border that bacterial wilt kills quickly.
How much it matters: Connecticut trials on summer squash: over 94% of the beetles were on the perimeter plants, beetle numbers on the unsprayed center fell by up to 95%, and spraying the border cut vine borer on the center by 88%. Those are field-scale figures; no garden-scale figure is stated or estimated, which is why it is rated promising, not well established, and only advises.
The evidence
Evidence: checked against 3 sources in the research-based literature.
The 3 sources
Perimeter Trap Cropping (PTC) involves planting the attractive plant species so that it completely encircles the main crop, like fortress walls
Plant 1 or 2 rows of a C. maxima variety in an unbroken perimeter around the field [...] and space plants no wider than the between-row spacing that is used in the main crop
Plant a few highly attractive cucurbits, such as blue hubbard squash. Plant your trap crop a week or two before you plant the rest of your cucurbits, as the beetles tend to show up in one early-season flush.
Plant teams that rest on it
How this rule has changed
Every change is dated, newest first. The full record, with each reason, is in the data download.
- Wording made clearer
- Added to the rules
Plan a bed with Perimeter trap crop ›
More ways Milpa can help
When do I plant? · What grows well together? · Plan my garden · What can I plant now? · Something wrong in the garden? · Keep a garden diary · Heard a tip?
Cite this page
Milpa Gardens. “A border of a more attractive cucurbit (blue hubbard, a winter squash), planted a week or two before the crop and kept unbroken around it draws striped cucumber beetles to the edge, where they are dealt with, so most of the beetles, and the bacterial wilt they carry, never reach the cucumbers, melons or summer squash inside.” Evidence grade: Promising. https://milpa.garden/rules/border-more-attractive-cucurbit-blue-hubbard-cucurbita/
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.
Report a problem with this claim
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.