A beloved climbing bean with fiery red flowers and tender pods, ‘Scarlet Emperor’ brings colour and yield to every summer garden. Easy to grow, loved by bees, and full of flavour — it’s a vertical summer classic with heritage charm.
Some plants belong to a different rhythm — old allotment rhythms, where beans rattle dry on string in the shed and early summer mornings are spent tying vines with weathered hands. The Scarlet Emperor runner bean is one of those plants. A name passed down through gardens and generations, it’s as much a visual memory as a crop: scarlet blooms flickering above leafy wigwams, pods hanging like green ribbons waiting to be gathered into baskets.
This classic variety of Phaseolus coccineus is cherished not only for its generous yields but also for its ornamental beauty and nostalgic charm. With bright red flowers that draw in bees and long, tender pods that capture the essence of summer, Scarlet Emperor is as much at home in a productive garden as it is in a potager or coastal cottage plot.
The growing season begins with decision and timing.
For an early start, seeds can be sown indoors from mid-April. Use deep pots or root trainers filled with rich, moist, well-drained compost. Sow one seed per pot, about 2.5cm deep, and keep in a bright, warm place (ideally 16–21°C). Germination usually takes around 7–14 days. As soon as the seedlings have two true leaves and the roots fill the pot, they can be hardened off and planted out once all frost danger has passed.
Alternatively, sow directly outdoors from mid-May through June, once the soil has warmed. Choose a sunny, sheltered position — runner beans thrive in warmth and hate cold feet. Sow seeds 5cm deep and 15–23cm apart at the base of a tall support structure. A wigwam, double row, or teepee of canes works beautifully, not just functionally but also visually — like green towers lifting towards the sky.
Scarlet Emperor demands good soil but rewards you many times over. Work compost or well-rotted manure deeply into the bed ahead of sowing or planting. Loamy, moisture-retentive, well-drained soil is best, ideally with a pH between 6.0 and 7.0. On heavy soils, consider digging a trench in autumn and filling it with organic matter before backfilling — the classic runner bean trench method, used for decades to store moisture and nutrients through summer.
These beans climb tall — up to 3 metres — so position them somewhere sheltered from strong winds and where they can stretch freely in full sun. An open spot, protected but bright, helps ensure reliable flowering and pod development.
Young plants need steady moisture and protection from slugs and snails. Water seedlings gently at the base and use wildlife-friendly deterrents if necessary. Once established, watering becomes crucial — especially during flowering and pod setting. Dry soil at this stage can cause flowers to drop and reduce your harvest.
Water deeply, two to three times per week in dry weather, rather than frequent light sprinkles. Mulch with compost, straw, or grass clippings to lock in moisture and keep roots cool.
Feed plants every two weeks once flowers begin to appear, using a high-potash liquid fertiliser (such as tomato feed). This supports strong pod formation without encouraging excessive leaf growth.
As a traditional climbing variety, Scarlet Emperor needs sturdy support. A double row of canes tied at the top, a wigwam of hazel poles, or even an archway or tunnel can serve both practical and ornamental purposes. Tie in the young stems if needed, though they’ll soon find their way upward naturally.
Pinch out the tops when the plants reach the height of their supports. This encourages branching and helps concentrate energy on producing pods rather than excessive top growth.
Pods form from midsummer onwards, often beginning in July and continuing well into September. For best flavour and texture, pick the pods while they are young and tender — around 20–30cm long. Use two hands to avoid damaging the vines: one to steady the stem, the other to snip or twist.
Regular harvesting (every two to three days) is essential. Letting pods mature on the vine slows further flowering, while constant picking keeps the plants productive and flourishing.
The beans are sweet and full-flavoured, perfect for steaming or slicing into summer salads, or cooked gently in butter with a handful of herbs.
While Scarlet Emperor is a reliable and generous variety, there are a few things to watch for:
Scarlet Emperor isn’t just a bean — it’s a vertical story in your garden. A climbing celebration of colour and abundance that transforms any patch into a living, flowering, fruiting structure. For Cornish gardens with their ocean light and sheltered pockets, this bean feels perfectly at home — thriving in the warmth, catching the breeze, and offering beauty and bounty in equal measure.
Sow it for the harvest, yes. But also sow it for the colour, the childhood memory, the bees, and the way the green towers fill up with the sounds of summer.
