Nasturtium Companion Plants

Claim. Nasturtiums are said to lure black bean aphids away from beans. Nasturtiums are a favoured aphid host, but no study shows reduced aphids on adjacent beans.

Mechanism. Proposed by tradition; not demonstrated in a controlled comparison.

Conditions. Planted together Both plants must be present at the same time.

Applies when. Optional experiment, not a guarantee.

Limitations. Aphids multiply on the nasturtium and can spread to beans unless removed.

Evidence. Tier D: Traditional knowledge or structured community observations without a controlled comparison. (tradition).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record nasturtium--bush-beans--trap_crop v1. Request a correction.

Claim. Nasturtiums are said to draw cabbage white butterflies and aphids away from brassicas. They are certainly colonised by both pests; the review found no controlled trial showing that nearby cabbage benefits.

Mechanism. Proposed by tradition; not demonstrated in a controlled comparison.

Conditions. Planted together Both plants must be present at the same time.

Applies when. Optional experiment, not a guarantee.

Limitations. Unmanaged, a nasturtium covered in caterpillars or aphids is a nursery, not a trap. Trap cropping needs the pests on the trap plant to be removed.

Evidence. Tier D: Traditional knowledge or structured community observations without a controlled comparison. (tradition).

Sources. University of Minnesota Extension 2023; Shelton 2006

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record nasturtium--cabbage--trap_crop v1. Request a correction.

Claim. Nasturtiums are said to deter cucumber beetles and squash bugs. No controlled evidence was found; the documented cucumber-beetle strategy is a Blue Hubbard squash trap crop.

Mechanism. Proposed by tradition; not demonstrated in a controlled comparison.

Conditions. Planted together Both plants must be present at the same time.

Applies when. Optional experiment, not a guarantee.

Limitations. Tradition only.

Evidence. Tier D: Traditional knowledge or structured community observations without a controlled comparison. (tradition).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record nasturtium--cucumber--pest_suppression v1. Request a correction.

Claim. We did not find a source that establishes a benefit or harm between winter squash and nasturtium.

Mechanism. None documented.

Conditions. Planted together Both plants must be present at the same time.

Applies when. The planner evaluates spacing, light, water and timing normally.

Limitations. Traditionally paired against squash bugs; no evidence found.

Evidence. Unknown: No source meeting the inclusion rules. (none).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record winter-squash--nasturtium--other v1. Request a correction.