Companion Plants for Watermelon
Traditional companions for watermelon include borage, chamomile, dill, nasturtiums and pumpkins.
These are garden traditions, collected from 8 US extension guides. Few have been tested in trials, so treat them as a starting point: spacing, sun and rotation matter more.
Good companions for watermelon
Spacing is per square foot, for a raised bed planted square by square. Cool-season companions can share the bed before or after a warm-season crop, or grow in its shade.
| Plant | Kind | Spacing | Season |
|---|---|---|---|
| Pumpkins | Vegetable | 1 per 9 sq ft | Warm season |
| Borage | Herb | 1 per sq ft | Cool season |
| Chamomile | Herb | 4 per sq ft | Cool season |
| Dill | Herb | 1 per sq ft | Cool season |
| Nasturtiums | Flower | 1 per sq ft | Warm season |
What the evidence says
Companion planting charts come from long garden experience, and most pairs have never been tried in a replicated trial. Several extension services say so directly; one review gives traditional charts more entertainment than scientific value.
What reliably helps watermelon: the right planting dates, enough space, and moving crops to a new bed each year (crop rotation).
Plant them side by side
Draw your beds, tap squares to plant watermelon next to their companions, and get every crop's planting dates for your ZIP code. Free, in your browser.
Questions
What can I plant with watermelon?
The traditional companions are borage, chamomile, dill, nasturtiums and pumpkins. Plant companions in neighbouring rows or squares rather than in the same hole.
Does companion planting with watermelon work?
Most pairings are tradition rather than tested results: extension services call companion planting promising but largely unproven. None of the pairs for this crop has been tested in a trial we could find. Good spacing, sun, water and rotation do more for a harvest than any single pairing.
How close can borage grow to watermelon?
In a raised bed planted by the square foot, give watermelon 1 per 4 sq ft and borage 1 per sq ft, in neighbouring squares. In rows, watermelon needs 36 in between plants.
More companion plants
Sources
- UC Master Gardener Program, UC ANR: Companion Planting Chart: Companion Planting for Edible Crops
- University of Wisconsin–Madison Extension, Kenosha County: Companion Plants for the Vegetable Garden (column, 2012)
- Oregon State University Extension Service: Herbs and Flowers in the Vegetable Garden
- Utah State University Extension, Utah 4-H: Creating Sustainable School and Home Gardens: Companion Planting (2025)
- Penn State Extension: Herbs Make Good Plant Partners and Companions
- University of Arizona Cooperative Extension, Yavapai County: The Art of Companion Planting (Master Gardener presentation, 2023)
- Clemson Cooperative Extension HGIC: Plant Partners: 5 Benefits of Companion Planting (2025)
- N.C. A&T State University Cooperative Extension: Five Veggies You Can Grow at Home