Growing peas and beans: legumes

Peas and beans come under legumes for crop rotation. They need plenty of organic matter dug in to keep their roots moist. Taller varieties of peas and beans are not suitable for deep dug beds as the soil is unlikely to hold stakes rigid enough. Because legumes make their own nitrogen they need little extra fertilizer. Taller pea and bean varieties can be used to shade summer grown lettuce, land cress or Chinese greens that would otherwise go to seed in hot weather.

Staking peas and beans

Most taller varieties of peas and beans need some support.

Asparagus peas

These do not grow very high, about 45cm/18in, but will still need some support. Use a short twiggy stick for each plant to cling to.

Broad beans

Taller varieties of broad beans need supporting. Use stakes that when hammered into the ground stand 90-120cm/3-4ft above the soil and place on each corner of each short double row. You will need extra stakes in long rows. Tie twine from one stake to the next about 30cm/12in above the soil and across row ends. When the plants are about twice this height tie in a second row of twine higher up the posts and a third if necessary.

French beans

Dwarf varieties will not need staking but climbing French beans which grow to about 2m/6-7ft need strings, canes or nets to climb up.

Runner beans

The traditional support for runner beans is to use two 2.4m/8ft poles or canes, crossed and tied at the top, to form an inverted V. A row of these is placed with one pole at each point where a bean is planted and the row is held rigid by a horizontal cane at the cross points. Alternatively, a length of twine can be used pegged into the ground at each end of the row and attached where each pair of canes crosses. Another method is to use a T-shaped support with twine pegged into the ground at each plant point, then up and over the top of the T to form the inverted V.

If you want to grow the plants up a wall, fix two horizontal battens to the wall one just above the soil, one about 3m/1oft from the ground. Position nails at plant-spaced intervals along the battens and tie vertical lengths of twine between the two. Instead of using a soil height batten you can anchor one end of the string with the plant’s root ball itself.

In the flower garden, beans are often grown up wigwam shapes constructed from canes but beans are ornamental enough to clothe a pergola, or surround an arch, particularly if you are waiting for a rose to climb around either.

Dwarf varieties are also available or you can pinch out the growing tip of runner beans when they reach a height of about 3Ocm/l2in to produce your own dwarf plants.

Peas

Depending on variety, peas can grow from 45- 120cm/18in-4ft. Although they can be grown without support, a system of posts with wires or netting stretched between them will keep the plants off the ground. Twiggy sticks about 120cm/4ft long are the traditional supports for peas, if you can find them. Place one beside each plant. Whatever supports are used, make certain they are sufficiently thin for the tendrils to grasp and as tall as the expected height of the variety grown.

In deep beds use a leafless variety and plant every 5cm/2in in rows 15cm/6in apart. Here the plants will support each other.

Mangetout and asparagus

These can grow up to 2m/7ft tall depending on variety. Support tall varieties in the same way as runner beans. Dwarf varieties are also available.

After harvesting

In warmer areas, after harvesting early crops you can cut broad bean plants back to 5cm/2in above the ground and they will grow again to provide a second crop. Peas and beans and broad beans in particular have nitrogen-fixing bacteria in their roots which will improve soil fertility for future crops, so when beans are harvested cut off the stems just above soil level, cut them up and add to the compost heap. Dig in the stem bases and roots. If you have any seeds left after planting use these up in any spare
plot of ground later in the season for a late harvest and to provide nitrogen for future crops.