If planted in a well-drained site, with protection for the roots from frost over the winter, runner beans can be grown as a perennial. Otherwise, enjoy them as fast-growing annuals plants. Runner beans are botanically different than regular pole beans. They prefer cool summer weather and will drop their blossoms if it gets too hot. They also need more moisture and cool roots all summer. Unlike snap beans, runner beans require pollination by bees to set seed. Fat, slightly fuzzy pods have a richer, "beanier" flavour than snap green beans. Below are some of our top tips on how to grow runner beans from seed.
We Recommend: Scarlet Emperor (BN127). Tall to the point of being massive, these vines just keep growing. Starting in mid-summer the plants are festooned in brilliant scarlet flowers – and then come the beans by the bushel.
Season & Zone
Season: Warm season
Direct sow from late spring to early summer. Try to plant during a warm, dry spell. Soil must be warm – if it is not warm enough, seeds will rot, especially our untreated seeds. Optimal soil temperature: 21-32°C (70-90°F).
Seeds can be started indoors, or sowed directly. Set seeds 7-10cm (3-4″) apart and 3.5cm (1½”) deep at the base of a support. Plants will climb by twining around almost anything. Try rough poles, lumber, re-bar, or build a strong trellis 2-2.5m (6-8′) tall. Seeds will sprout in 8-16 days, depending on soil conditions.
Ideal pH: 6.0-6.5. Well drained, warm soil in full sun is best. Use 1 cup of complete organic fertilizer for every 3m (10′) of row. Too much nitrogen in fertilizer or manure may cause poor pod set and delayed maturity. If beans flower but do not set pods, the cause can be zinc deficiency. Try spraying the plants with kelp based fertilizer. Wet leaves on crowded plants are subject to diseases. Thin plants to increase air circulation and avoid touching the leaves while they are wet.
Beans can be picked when plump-looking. You may dry beans to preserve them, or cook them soon after harvesting. You must ensure that you cook these beans thoroughly; raw runner beans contain lectin, a toxin that is removed by the cooking process.
In optimal conditions at least 75% of seeds should germinate. Usual seed life: 3 years.