Seed Saving for the Fabaceae (Leguminosae) Family

Genus

Species

Common name

Glycine

max

soybean

Phaseolus

coccineus

runner bean (e.g. scarlet runner, black seeded runner)

vulgaris

common bean (e.g. Borlotti stoppa, Bob’s bean, purple pod, blue lake)

Pisum

sativum

garden pea, edible podded pea (e.g. Amish snap, Bohemian sugar pea, Picton Sno)

Vicia

faba

broad bean

Pollination: Fabeaceae flowers are self pollinating, and do not usually cross within species or between species. However, there are some exceptions to this. In New Zealand, the coccineous species (runner beans) cross freely, as do Vicia faba (broad beans). I have also seen, and other seed saving organisations are saying the same, that there are some Phaseolus beans that also seem to readily cross. A lot of people get confused with ‘climbing beans’ and ‘runner beans’. Runner beans refers to the P. coccineus species (Scarlet runner family) which are climbing beans and cross very readily with other runner beans. However beans from the Scarlet Runner family (P. coccineus) don’t cross with climbing or bush beans  (Phaseolus vulgaris), nor do they cross with Broad beans (Vicia faba) or peas (pisum sativum)

Isolation Distances: Isolation distances for P. coccineus are bee flying distances – it appears bees will travel far to visit these flowers, so it is important to keep them well isolated if you want to save the seed!  The other ‘climbing beans’ which are common are climbing varieties of P. vulgaris. These are self fertile and do not usually cross with other members of that species, although I have seen that a small number if the P. vulgaris species in our collection do seem to cross. There are also dwarf and bush varieties of P. vulgaris (also self fertile). Because they are self fertile, you can save seed from only one plant if necessary to keep the line going. Isolation is not usually necessary. Peas are self fertile and do not cross, so isolation distances are not necessary. Broad beans are pollinated by bees and insects and do readily cross, which means they need to be isolated by bee flying distance, which will depend on terrain.

Minimum Numbers: 1 plant will do (although it is better to save from more), except the P. coccineus and broad beans, where minimum numbers should be 16, preferably 32.

When To Plant: The best bean seed (vulgaris and coccineus and other warm climate warm season beans) will be saved from plants going into the ground when it warms in Spring (October or November). Cool season beans and peas are best planted in early Spring to achieve optimal seed crops.

Rogueing: Watch for signs of disease resistance, flavour, production, adaptability to your local conditions, and save seeds from the best. Eat the rest.

Support/Protection: Many beans and peas need support anyway just to harvest an edible crop, and broad beans sometimes need a string fence around the bed or something similar to prevent lodging, however  you may also have to keep birds off your pea crops to harvest the seed. We hang netting over the pea trellis’s.

Harvest: The easiest way is to be able to leave your beans and peas on the vines until they are crunchy dry.

Drying: If you are unable to do this they can be picked before fully dry and the drying finished in the greenhouse etc.; they must be crunchy dry to easily extract the seed.

Threshing: Beans and peas are the easiest to clean and the most fun, because the seeds are so beautiful. Tip onto the ground on a tarpaulin or into a cut off barrel (see diagram 3), and jump on them. The seeds come out easily and the pods can be simply removed by hand.

Winnowing: If you pick the barrel up at one end, about 20cm off the ground, and shake it, the seeds will all go to the bottom and the chaff will go to the top. Remove rough big chaff by hand then tip the seed from one container to another in the breeze to extract the remaining finer chaff. You can also rub the seed on a screen so that the finer chaff falls through. Beans attract weevils, so I always freeze my bean seed before storing.

Seed Life Expectancy: Runner beans will retain 50% germination if kept cool, dry and dark for 3 years, peas for 3 years, broad beans for 6 years, common beans for 4 years.