Peas and beans are a great place to start in seed saving. The seeds are big and easy to harvest; they can be produced in one year and keep well. Reserve a row or part of a row from your first sowing and do not pick any of the pods on these plants. When the bottom pods are starting to dry out and split, cut the plants down and spread them out in the sun to dry on a sack or a piece of plastic. If the weather is wet, hang them up in a shed or tunnel. I find the paper grain bags for cattle feed useful as they are big enough to hold a good few plants and the seeds if they fall out of the bunch end up in the bottom of the bag. When the pods crack crisply they can be shelled by hand into bags and hung from the shed roof to avoid rodents. Seed needs to be pretty dry to keep well. If it is really dry it can be put in an airtight container if not it is better in a paper bag so that it can breath. It should shatter when hit with a hammer rather than squash. Once dry seed needs to be cool so the back bedroom or the fridge is good. Rodents love all seeds so the garden shed is not always a good place.

The three species of beans will not readily cross with each other, and not at all with peas, so you can ignore the possibility when planning where to plant.

a) Broad beans: 800 meters from other broad beans. Pollinated by bees and as varieties cross very easily with each other, grow only one variety each year. Beware farmers growing field beans anywhere in the vicinity.

b) Runner beans: 800 meters from other runners as cross-pollinated by bees. Grow only one variety each year or put an insect-proof fleece bag around each flowering truss required for seed and initiate pollination by pressing down the lower part of every flower as it opens to mimic a bee landing.

c) French beans: a few meters from other French bean cultivars.

d) Peas: Opinions vary. Some authorities suggest 25-100 meters from other peas. Others advise merely that as a minimum barrier between two different types of pea.

The first pods to form are usually the best to save as seed as they tend to be bigger. Label the seed from each year’s harvest and keep it separate. This is because if a crossing has accidentally occurred, it will probably reveal itself by changes in the colour or the shape of seeds in the second generation. If you notice suspicious changes, throw away (or eat), both the affected peas or beans, and those of the previous crop. It is necessary to go back two years to restore purity. Peas and all three types of bean will keep for a least three years if kept cool and dry.