Growing Scarlet Runner Bean: A Complete Profile
By Growing Home Greens Team · August 10, 2026
Scarlet runner bean is a vigorous flowering vine in the same genus as garden beans, but it’s usually grown for its bright red, edible flowers and ornamental value on a trellis rather than for the bean pods, which are edible too but a secondary reason to grow it.
Sowing it
Transplant, starting 2 to 3 weeks before your last frost with two seeds per cell thinned to one plant, or direct-seed after your last frost once soil reaches at least 60°F, sowing 1 inch deep at about 6 seeds per foot. Germination takes just 4 to 7 days at 60-70°F. Space plants 4 to 8 inches apart.
A trellis is not optional
This vine climbs 9 feet or more in a single season, so a sturdy trellis needs to be in place before or right at planting time, not added later once the vine is already sprawling. A nitrogen-fixing inoculant applied at planting, the same kind used on other beans and peas, improves both flowering and pod set.
Harvesting the flowers
For edible flowers, harvest when they show strong color, either as unopened buds or fully open blooms. Unopened buds hold in the refrigerator for 2 to 3 days if not used right away. Left on the vine, the flowers develop into large, edible pods similar to other runner beans, best picked young before they toughen.
Scarlet runner bean has no recorded companions or antagonists in our data. See the full companion guide for scarlet runner bean for how it’s tracked. Given its height, it needs a dedicated trellis spot in the Garden Designer, ideally on the bed’s north edge so it doesn’t shade shorter neighbors.
Source: Scarlet Runner Bean: Key Growing Information, Johnny’s Selected Seeds.
Companion planting guide for Scarlet Runner Bean · Find your planting dates
Typically viable in USDA zones 2-11. Not sure your zone? Look it up by ZIP code.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Scarlet Runner Bean tolerates either.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Scarlet Runner Bean plants fit per square foot?
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 6-9 ft.
Varieties worth considering
- Straight-species scarlet runner bean (Phaseolus coccineus): Johnny's Selected Seeds sells it as the plain species; there's no meaningful named-cultivar market beyond it and a white-flowered selection sold occasionally by specialty catalogs. The red-flowered species is what most gardens grow and what most seed racks sell. (source)
Cited from the source shown next to each variety. We haven't grown these ourselves yet, so treat this as a research-backed starting point, not a personal endorsement.
Where to buy scarlet runner bean seeds
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See it growing
Search YouTube for "growing scarlet runner bean" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Scarlet Runner Bean: A vigorous flowering vine in the same genus as garden beans, grown as much for its bright red edible flowers as for the pods themselves.
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