Runner Bean Seeds in Ireland

How to sow runner bean seeds

Runner bean seed is large, easy to handle and quick to germinate, which makes it one of the best crops to sow with children. The one thing it will not tolerate is cold wet compost.

Sow indoors from late April to mid May, one seed to a 9cm pot or a deep root trainer, 5cm deep. Depth matters here: a shallow-sown runner bean makes a poor root system and blows about once it is climbing. Water once after sowing and then wait, because a soaked pot in a cold shed rots the seed.

Germination takes seven to fourteen days at 12 to 20C. An unheated greenhouse, a porch or a bright windowsill is warm enough in May. Grow the plants on until they are 15 to 20cm tall with the first twining tendrils showing, then harden them off for a week before planting out.

Direct sowing into the ground works from late May in the south east and the south coast, and from June across the rest of the country, once the soil is above about 12C. Sow 5cm deep, 20cm apart, with a spare seed at the end of each row to fill gaps. Direct sown beans catch up fast, but they are far more exposed to slugs and cold.

Support and shelter

Build the support before you plant, not after. The classic Irish failure is a row that stands perfectly all June and goes over in the first August gale, taking a full crop with it.

Use 2.4m canes or hazel rods driven at least 30cm into firm soil. A double row with the canes crossing near the top and a horizontal cane lashed along the ridge is the strongest arrangement, and a wigwam of six to eight canes tied hard at the apex comes next. Tie every crossing point with garden twine rather than trusting the plants to hold it together.

Orient the row so its narrow end faces south west, which is where most of our weather arrives from. Siting the row along a hedge, a wall or a fence rather than in the open middle of a garden is worth more than any amount of extra tying.

Plant out at the very end of May on the coast and in early June elsewhere, one plant to each cane, once frost risk has passed. Guide the first shoot onto the cane in an anticlockwise direction and it will do the rest itself.

Growing on

Runner beans want a soil that stays damp. A trench filled with compost or well-rotted manure the previous autumn is the traditional preparation and it works, because the organic matter holds water exactly where the roots need it in July.

Mulch the base of the row once the soil has warmed, and water heavily once a week rather than a splash every evening. Dry roots during flowering is the single biggest cause of a disappointing crop here.

Pinch out the growing tips when the plants reach the top of their supports. This stops them making a heavy tangle above the canes that catches the wind, and it usually takes the worst of the blackfly with it.

Feeding is rarely necessary in decent ground, since the plants fix their own nitrogen. A high potash feed once flowering starts does help on thin or sandy soil.

Harvesting

First pods are ready roughly twelve to sixteen weeks from sowing, which means late July for an April sowing and August for a June one. Pick when the pods are 15 to 20cm long and still flat, before the beans inside start to swell and show through the wall.

Pick every two or three days without exception. Runner beans crop for as long as you prevent them from ripening seed, so a fortnight’s holiday in August can end the season. If pods do get away from you, strip them off and compost them and the plant will start flowering again within a week or two.

Cropping continues until the first frost blackens the plants, which is usually October and can be November in a mild coastal garden. At the end of the season cut the tops off for the compost heap and leave the roots in the ground.

A heavy crop freezes well: top, tail, slice, blanch for two minutes and freeze on a tray before bagging.