Legumes are a family of plants that are essential to the garden. Because of a symbiosis they have developed with nitrogen fixing bacteria, which live in special nodes on their roots, they can fix atmospheric nitrogen (from the air) into forms that our veges can utilise in the soil (nitrates and nitrites). Awesome if you're not into buying synthetic nitrogen in a bag from your friendly local multinational chemical corporation...
WHEN TO GROW: Broad beans can be sown in both early spring (Aug-Sept) and Autumn (March-May). Some varieties are suited better to one or other of the two planting times. In Dunedin, an autumn planting is the most reliable way to get a large crop of broad beans in the late spring.
GERMINATION and PLANTING: Broad beans are best planted straight into the position in which they are to grow, to avoid root disturbance. If you are to start them in trays (or ideally, newpaper or peat pots to be planted straight into the ground), aim for as little root disturbance as possible on transplanting. Seeds should be planted 3-5cm deep and plants should be about 10-20cm apart, although spacing is also up to personal preference.
Broad Beans are best planted in a group rather than in just a single row. This is because in a group the plants will support each other and not fall over. However in a windy garden it may also be necessary to bang in a few sticks around the patch and run some strings through the beans from stick to stick, to help with support.
WATERING and FERTILISER: Broad beans are not too fussy about the quality of their soil although obviously a nice rich loamy soil will do the best. But as they are a legume you can grow them in some of the less than ideal sections of the garden, to boost nitrogen levels, and when you're done picking beans you can just mix the stems and leaves into the soil where they grew.
Broad beans are fans of potash. Mixing some wood ashes and compost into your soil before planting can help, or water with comfrey tea (or mulch with comfrey leaves).
HARVESTING: You can harvest broad beans at their young stage, when the pods have not become too tough and woody, or they can be harvested when large and mature. If you harvest the pods quite young you can eat the beans without 'skinning' them (described below).
If you let the pods get to full size and the beans mature, most people end up also removing the outer skin of each individual bean, which becomes kind of grey and loose. You simply 'pinch' the beans out of their skins. But this takes quite a long time!
WHEN TO GROW: Sow seeds Sept - Oct. Plant seedlings Oct-Nov.
GERMINATION and PLANTING: Seeds can be planted 2-3cm deep in a tray or small pots, or direct sown in the ground. Keep moist until germination occurs and then water well after that. When seedlings are 10-20cm tall or so, if not direct sown, plant them out in your garden 15cm apart.
They will need strings or mesh to climb up. You can tie strings to any nearby objects that are high up, or build a 'bean frame' out of bamboo sticks or other wood, with strings going from the top (about 2m tall) down to the ground. Like broad beans, runner beans like potash. Comfrey leaves can be buried in the trench before seedlings are planted, or you can use comfrey or grass clippings as mulch.
WATERING and FERTILISER: Runner beans enjoy a decent supply of water, since they have such a large surface area of leaves where water can evaporate from. Moisture retention can be increased in the soil by mulching around bean plants with straw or dried grass clippings. Fertilise with liquid comfrey tea or other liquid organic fertiliser from time to time for an increased yeild.
HARVEST and USE: Beans should be picked regularly as this will encourage production of extra pods on the plant. Leaving large pods low down will starve the rest of the plant of the nutrients it could use to produce lots of beans. For young-picked beans, use them as you would use any bean-in-pod.
Nearer to the end of the season you may choose to leave pods to mature and dry. You can then take out the semi dried beans from inside these pods, dry them out completeley and store them as dried beans. To use them, bring them to a boil in some water and then simmer for a couple of hours or until the beans are soft. Use them as you'd use kidney beans etc.
WHEN TO GROW: Sow seeds August to April
SOWING SEEDS: Peas are quite happy to be direct sown, and benefit from not having their roots distrubed during transplanting. Soaking seeds in water for a few hours prior to planting can help with germination.
Sow seeds to a depth of about 2cm and spaced between 5 and 15cm apart. Peas can flourish under crowded growing conditions. Give them something to climb up, whether its sticks poked into the ground, trellis, strings, etc. Peas cannot wrap their tendrils around anything bigger than about a pencil, so make sure that whatever structure you make has things on it for the peas to grip on to.
WATERING and FERTILISER: Peas like their roots to be constantly moist. But the soil must be free draining as they are sensitive to rot if growing in standing water. A mulch layer will help hold in moisture. Peas are not heavy feeders and as they also fix nitrogen from the air, they can be grown with little or no prior addition of compost, although they will crop even heavier in a well manured soil.
HARVEST and USE: Peas can be harvested and used as fresh green peas when removed from their pods. But you can also dry them and use them as you would use split peas or lentils. They are very delicious like this and can be a great crop to eat in the winter when not much else is around.