Leguminous Vegetables

This section describes my experience in growing beans. Peas also count as leguminous vegetables, but are not inlcuded here as I have had very limited success in their cultivation. "Leguminous" describes any vegetable that is capable of "fixing" nitrogen - combinnig unbsuable gaseous nitrogen from the air with hydrogen and oxygen to form usable nitrogen compounds. This is achived by symbiotic association of bacteria in root "nodules". Further information on this is given by the John Innes Centre. After the plant has produced a crop and died, its fixed nitrogen is released to the soil and hence these plants improve the fertility of soil in which they have grown.

Ground Preparation

On all soils except the most fertile, planting above a "bean trench" is necessary for a good crop of beans. Dig a trench to at least 1 spades depth and cover the bottom with 25-50mm (1-2") of manure, compost or grass cuttings. Re-fill the trench with the excavated soil and mark its position. Try to do this at least two weeks before planting.

Broad Beans

Broad, or fava, beans (Vicia faba) are frost tolerant beans, cropping from early summer onwards. Some varieties, Aquadulce, can be planted the previous autumn and seedlings left to overwinter. The large seeds are planted to twice their own depth. Watering is necessary as the plants start to grow and is critical when flowering to ensure a good crop.

Climbing French Beans (Phaseolus vulgaris) and Runner Beans (Phaseolus coccineus)

These well known and decorative beans need supports to grow. The most widely used method is to tie two rows of bamboo canes together with horizontal "topbars". Bamboo canes can also be used to build wigwams; however it is more difficult to dig bean trenches in hexagonal form to allow this. Both french and runner beans can only be sown outdoors once the soil has warmed properly and there is no danger of frost; typically early June. Earlier sowings can be made in a greenhouse in containers and transplanted once night temperatures are above 6°C. Sowings are made by pushing the large seeds into twice their own depth of soil. These crops require a moist soil at all times and thus should be watered every 48-72h throughout June July and August, unless it rains.

Dwarf French beans

These beans are cultivated like their climbing cousins, except without the need for supports