At the end of autumn when the summer crops are done, you'll find my kids tearing up and down the driveway, running over pillowcases on their bikes, and getting pocket money to do it. Those pillowcases are filled with dried bean pods in need of threshing, and there's no greater source of carbonneutral energy than a 10-year-old on a bike with icy-pole cash on her mind.
When the riding is done we empty the pillowcases onto sheets and throw big handfuls of beans and pods into the wind, winnowing the light pods away and leaving behind a pile of shiny beans, ready for a jar in the pantry.
I love baked beans, refried beans, white-bean dip, feijoada - you name it. In the coldest part of the year a rib-sticking dish of beans, laden with protein and carbohydrates is just what you need. In any dry-goods store the range is dazzling and the beans are dirt cheap. According to my farm budget equations there is no way I can sow, tend, harvest, dry and thresh them for sale and come out even; not when the same amount of land and work that produces five bucks' worth of beans could yield $20 worth of lettuce. But sometimes, for the good of your pantry, and for the good of your soul, you throw your spreadsheets to the wind, and plant drying beans.
This year we grew two types of pinto to indulge our inner cowboys, an Estonian Black drying bean, Lazy Housewife climbing beans, highly sought-after borlotti beans, and, the best bang for my dry-bean buck, scarlet runner beans - surely the muse for Jack's magic bean with their speckled purple and black shiny skins.
Plants are magicians. I'm not sure plant scientists would describe it that way, but to me the act of sowing a hard, dry bean seed and watching it transform sunlight, air and water (with the help of a healthy soil, of course) into solid matter, is nothing short of miraculous. And these beans have another, very special trick up their sleeves.
Nitrogen is one of the building blocks of chlorophyll, the stuff that makes plants green and enables photosynthesis. In our garden we choose not to use synthetic fertilisers, opting instead for natural sources of nitrogen, and the very best of these is that provided by those magic beans and their teammates, rhizobia bacteria. Unseen by us, underground, tiny rhizobia colonise the roots of leguminous plants - those in the pea tribe; think beans, chickpeas, peas, lentils, and even wattles - and trade with those plants; the rhizobia's skill of grabbing nitrogen from the air, in a symbiotic exchange for the plants providing them with a place to live and a ready source of carbon. At the end of the season the roots of these plants will be covered in white nodules made by the rhizobia and we'll leave these in the ground to break down and make their nitrogenous gifts available to the following crop.
This magic trick, and the fact that beans are a remarkable source of protein, fibre, essential minerals and carbohydrates, not to mention the diversity of flavour and texture, has led the UN to declare 2016 the International Year of Pulses. In regions where you can't pop to the rural supplies store for a bag of fertiliser, a plant that produces a food that contains most of the essential nutrients for life, stores beautifully and tastes good, as well as improving soil fertility, is invaluable.
Although my accountant may think it imprudent of me to toss out those spreadsheets, the pleasure of running my fingers through a bowl of those shiny, magic beans before covering them in cold water to soak cannot be accounted for in Excel any more than you can account for the satisfaction of cracking through the toasty, breadcrumbed crust of a tray of homegrown baked beans. So raise your bean-laden fork to the year of the pulse and to our tiny unseen allies, toiling away under the soil.