Runner beans like most of the beans do well in warm (15-25?C) and well drained and fertile soils. If you farming in Africa, warmth is available throughout the year and water! Well, depends on where you are. Contrary to popular believe, growing of runner beans if fairly easy in the tropics and especially in Africa. Beans can be used ideally as a rotation crop to add more nitrates to the soil.
The first important part in runner bean farming in Africa is soil preparation and this is no different for the runner beans. Runner beans require well drained, well ventilated and fertile soils. Compost or animal manure may be added to the soil before planting. Worth noting is that beans and other legumes don’t require nitrogen rich soils because they release nitrogen to the soil. Ideally fertilizers rich in phosphorous should be used to dress the soil before planting and during growth.
Once the soil is well prepared, the beans are planted directly to the soil at a depth of about two inches and 2 feet apart. Since runner beans are climbers, strong poles of 7 to 9 feet should be erected and joined across to form a Tee before planting to support the climbing plants other methods of support, like a fence or some form of a wigwam structure of support, can be used depending on the area where the beans are being grown. The plants do well in full sun and should not be shielded from the sun. Care should be taken to give enough space between plant to allow flowering and high yields. It is advised that no other plants be planted in the same plot as runner beans since their big leaves would shield other plants from the sun.
As the runner beans grow, they will need plenty of water,have water approx. five to ten liters twice a week or more especially when the plants begin to flower and pods develop. The plants should also be dressed with a phosphorous rich fertilizer during growth. The tips of the runner beans should be clipped once they reach the top of the supporting structure. The most common pests and diseases on runner beans include halo blight, slugs, aphids, halo blight is usually as a result of poor seed selection. When selecting the seeds for planting all wrinkled, marked and oddly shaped seeds should be removed from the seeds for planting.
If Halo is detected the plants should be removed since there is no cure. Slugs feed on all parts of the bean plant. There are several methods of dealing with the slug ranging from physical barriers, beer or milk traps, organic control or chemical control. Aphids are another menace to your garden, they mainly sack the sap off the plant stems and young shoots. Though they seldom kill the plant, they weaken it lowering yields considerably. Aphids can be controlled by use of chemical sprays, rubbing them off physically or use of washing up liquid.
Runner bean farming in Africa usually takes 10-15 weeks within which the crop is ready for harvest. It is important to note that maturity of plants depends a lot on the climatic conditions e.g. temperature and water and therefore the farmer should be aware of how the crop would look like at maturity. The pods of the runner bean would be approximately 6 to 7 inches when ready. Note that if not picked the plant stops flowering.