Dec, Jan, Feb, Nov
Dig out a trench about 60cm deep during late autumn or winter. Then start filling it with all your organic kitchen waste, such as vegetable peelings, mouldy fruit, apple cores, onion skins and even tea bags.
Each time you add a batch of kitchen waste, cover it with a layer of soil. Continue until the trench is full, then top off with soil and leave it to rot down. As it does so, it will hold on to plenty of moisture, which is just what beans enjoy.
In May or June, sow or plant your beans on top of the composting trench and their roots will go down into the moisture-retentive, nutrient-rich material, boosting their growth.