Scarlet runner beans produce edible beans packed with fiber and nutrients, but they are often grown for their ornamental value. These fast-growing vines reach heights of 10 feet or more when planted in a sunny location, and they quickly cover trellises and fences with heart-shaped leaves to offer shade to weary gardeners. Blooms appear in midsummer and grace the vines with abundant scarlet flowers that later develop into pods, producing rose-colored beans that are considered delicious.
Prepare an area for scarlet runner beans in a sunny location that receives at least 6 hours of direct sunlight each day. These hardy plants thrive in summer sun and prefer all-day sun in northern climates, but they may benefit from partial shade from the afternoon sun in southern gardens.
Till the soil to a depth of 6 to 8 inches and remove rocks, roots and other debris.
Add a 2- to 4-inch layer of compost or well-rotted manure. This will improve drainage and condition the soil. Mix it in well with the top 6 inches of soil.
Apply 1 cup of 5-10-10 fertilizer per 50-foot planting row and work it in well.
Plant scarlet runner beans in spring after the danger of frost has passed in your area and soil temperatures remain above 50 degrees F. Cool, damp soil inhibits germination, and seed often rots before sprouting if subjected to cold, wet soil for more than one or two days.
Plant bean seeds to a depth of 1/2 to 1 inch. Space them 3 to 4 inches apart and 2 to 4 inches from the fence or trellis that will be used for their support. These runner beans require a 10-foot structure, such as an arbor or trellis, for support.
Cover the seeds with soil and firm it down with the back of a hoe.
Water to moisten the soil to a depth of 2 to 3 inches. Keep the soil moist until the seeds germinate. Seedlings typically emerge within 7 to 14 days, depending on the soil temperature and moisture level.
Cultivate with a hoe, or pull weeds by hand, to the keep the area free of competing weeds. Use caution when weeding because scarlet runner beans develop shallow root systems and are easily uprooted along with large weeds growing close to the base of the beans. Pull weeds when small or cut them with the blade of the hoe to avoid damage to bean roots.
Water the bean plants deeply once each week. Allow soil to dry before watering again.