Green beans

Phaseolus vulgaris

Pick green beans young, while the pods are tender. Dwarf types grow to about 45 cm and suit pots. Climbing types need tall canes but keep giving beans for longer. Frost kills them and cold, wet soil rots them, so sow only once the soil is warm.

Looking after it

Water: Green beans need normal watering. Water in dry weather, most of all once they flower and set pods. Dry soil makes the flowers drop. Pots need water often. Feeding: They need little food. In the ground they need no feed at all and too much nitrogen gives you leaves instead of pods. In a pot, give a high-potassium liquid feed every two weeks from the first flowers.

Harvest and keeping

Pick the pods at 15 to 20 cm, when they snap cleanly and before the beans show through. Pick every few days. The more you pick, the more pods come. The pods keep a few days in a bag in the fridge. For winter, blanch and freeze them.

What can go wrong

Slugs and snails. Seedlings get eaten overnight. Raise plants in pots and plant them out once they are sturdy. Check for slugs on damp evenings.
Blackfly. Small black aphids crowd onto the shoot tips. Squash them or wash them off with a jet of water.
Flowers dropping. In hot, dry or windy weather, the flowers fall off without making pods. Keep the soil moist, especially while the plants flower.

Growing facts: RHS, UC ANR and seed-company sowing guides. Bean care: RHS and Virginia Tech extension. How many to grow: Kansas State and Texas A&M extension. pH: Virginia Tech and Penn State extension.