Pumpkin + Nasturtium

Nasturtium and pumpkin share a sprawling growth habit, which makes spatial planning the main consideration. Plant nasturtiums at the perimeter of the pumpkin patch or between hills at transplant time so they establish before pumpkin vines dominate the ground. Nasturtiums are documented to deter squash bugs and cucumber beetles, two of the most damaging pests for cucurbits in most growing regions. The mechanism is partly physical (dense trailing foliage confuses pest navigation) and partly chemical (volatile compounds in nasturtium tissue are repellent to several beetle species).

Both crops tolerate poor to moderately fertile soil, so nutrient competition is rarely a problem. In rich, heavily amended beds, nasturtiums tend to produce excessive foliage at the expense of flowers, which reduces their pest-deterrent value. This pairing is most useful where squash bug pressure is historically high. In low-pest gardens, the benefit is modest.