How to Grow Scarlet Emperor Bean
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Scarlet Emperor Bean
Phaseolus coccineus
vegetableScarlet Emperor is a ornamental runner bean variety with stunning bright red flowers and long, slender purple-red pods. Both the flowers and pods are edible, making it a dual-purpose plant that adds color and productivity to the garden. The vines are vigorous climbers that can reach 8-10 feet, ideal for trellises and vertical spaces.
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Example Scarlet Emperor Bean timeline · Pittsburgh, PA (Zone 6b)
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Plant Scarlet Emperor Bean
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Scarlet Emperor Bean
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Scarlet Emperor Bean dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 4-10; grows as annual in cooler zones, sometimes perennial in warmer zones
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Seedling
2-3 weeksCotyledons emerge and unfurl, developing the first true leaves. Rapid growth begins within 1-2 weeks.
Keep soil warm (65-75°F) and moist. Provide bright light. Thin seedlings if densely sown. Install support structure early.
Vegetative Growth
3-4 weeksVigorous vine expansion with multiple stems climbing up support. Leaves are trifoliate (three-lobed) and deep green. No flowers yet.
Guide vines onto trellis or support as they grow. Water consistently. Side-dress with compost or balanced fertilizer mid-growth. Monitor for pests.
Flowering
4-6 weeksBeautiful scarlet-red flowers appear in clusters along the vine. Flowers are papilionaceous (butterfly-like) and highly attractive to pollinators.
Maintain consistent moisture to support flower production. Avoid high nitrogen fertilizer which promotes foliage over flowers. Keep weeds managed. Bees and hummingbirds will visit.
Pod Development
3-4 weeksFlowers are succeeded by long, slender purple-red pods (6-8 inches). Pods begin as bright red and develop darker coloration as they mature.
Continue regular watering. Provide shade cloth in extreme heat. Pick pods regularly to encourage continued production. Support heavily laden vines.
Harvest
2-3 weeks per harvest windowPods are mature and ready to pick. Beans inside can be fresh and tender or allowed to dry for dry beans.
Harvest regularly when pods are young and tender (6-7 inches) for best flavor. For dried beans, allow pods to fully mature on vine. Wear gloves—some varieties can cause skin irritation when raw.
Common Pests
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Hand-pick adults and clusters of yellow eggs from undersides of leaves. Use row covers on young plants. Apply neem oil or spinosad if infestation is severe.
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Increase humidity with misting. Spray undersides of leaves with water to dislodge. Use insecticidal soap or neem oil for heavy infestations.
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Ensure good air circulation. Remove infected leaves promptly. Avoid overhead watering. Apply sulfur dust or copper fungicide if needed.
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Spray with strong water jet to dislodge. Introduce beneficial insects like ladybugs. Use insecticidal soap or neem oil.
Uses
Fresh snap beans and mature dry beans
CulinaryYoung tender pods can be steamed, boiled, or sautéed as a garden vegetable. Mature dried beans are excellent in soups, stews, and bean dishes. Note: raw beans must be cooked to remove toxins. [source]
Edible flowers for garnish
CulinaryThe bright scarlet flowers are edible with a slightly sweet, bean-like flavor and can be used fresh in salads or as a colorful plate garnish. [source]
Pollinator and hummingbird attraction
WildlifeThe vibrant red flowers are irresistible to bees, butterflies, and hummingbirds, making Scarlet Emperor excellent for creating wildlife habitat and supporting pollinator populations. [source]
Ornamental vertical garden cover
HouseholdThe vigorous vines with stunning red flowers and decorative pods provide both aesthetic beauty and productivity, serving as a living privacy screen or trellis covering. [source]
Dried pod and seed crafts
CraftThe attractive purple-red dried pods and colorful seed beans can be used in dried flower arrangements, seed art projects, and decorative displays. [source]
Harvest Tips
For fresh eating (snap beans), harvest pods when young and tender, approximately 6-7 inches long and before seeds bulge noticeably. Snap pods with a firm upward tug or use scissors. For dried beans, leave pods on vine until they brown and dry completely, then shell out beans. Regular harvesting encourages continued flowering. Pods contain toxic compounds (phytohaemagglutinin) when raw, so always cook thoroughly before eating.
Fun Facts
- 🌱 Scarlet Emperor is a runner bean, not a bush bean, and can grow 8-10 feet tall in a single season—some gardeners train them to cover entire pergolas or arbors.
- 🌱 The brilliant red flowers that attract hummingbirds are named 'scarlet' from the intense crimson dye traditionally used in royal robes and fabrics dating back centuries.
- 🌱 Runner beans were originally domesticated in Central and South America over 7,000 years ago and were introduced to Europe in the 16th century, where they became valued as both ornamental and food crops.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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