Runner beans love a mixture of sun and the rain and can go from tiny flower buds to almost fully grown in a very short space of time in the right conditions, you can almost pull up a chair and sit back and watch them grow!
They tend to grow well in rich soil. It is recommended to apply lime, compost or manure as well as a couple of handfuls of bone meal per square meter in preparation of their sowing. By doing this, you will ensure that the soil is as water retentive as possible.
You should always make sure that you give the soil enough time to settle after preparation – March would therefore be the best time to start preparing the bed where you’re planning going to grow them.
Grow runner beans from seeds rather from than seedling plants as you may face problems if the plants are not hardened properly. The seeds you sow are normally about 2cm long with a kidney shape and have a brown color on the inside of the curve and a pink and brown speckle on the outside of the curve.
Runner beans are a half hardy plant and so should be planted just before the last frost date. If you want to give them a head start (about 4 weeks), you can choose to sow them indoors or under cloches. Just ensure they are properly watered and in a warm, light, frost-free place.
When the plants germinate and have grown to about 15 to 20cm, you can go ahead and plant them outside.
Choose a site which is sunny and partly sheltered. Using a trowel, dig into the soil about 5cm deep and sow the seeds about 9 to 12 inches apart so they have room to grow properly. If you’re planting more than row, ensure the rows are 1.5m apart.
If the conditions are dry, make sure you water the bed well after sowing and continue to do so as they plants grow. To discourage slugs and snails – especially when the plants are still small and vulnerable – a collar made from a used yoghurt pot should be placed over each plant.
Because runner beans are a climbing plant, it is recommended you grow them up against a trestle fence or use bamboo sticks or poles to support them. Encourage them to twist round their supports as they grow and those that reach the top should have their tips pinched out to encourage growth from below.
The best time to pick them is while they are still tender, by this time the pods will have grown to about 6-8” long.