Green manure for winter
Vegetable patches and empty flower beds can look quite barren over winter and bare soil exposed to rain will loose nutrients. Wind can also blow away loose soil, although around Milngavie, the usually sodden clay soils are unlikely to travel too far on the breeze. Green manures stabilise the soil, and mop up the nutrients, acting as a 'nutrient bank' preventing them from being washed away. When dug back into the soil or pulled up and laid on top as a mulch in spring the absorbed nutrients are put back into the soil and the organic matter will help lighten our heavy soils. If legumes are sown, they can aslo can fix nitrogen in the soil. If thats not enough, they help to suppress weeds that might otherwise develope in the bare soil.
Practice crop rotation to prevent pest and disease build-up, so plant a winter crop of legumes for the space you want to plant brassicas in next spring. The added nitrogen will also benefit the brassicas. Field beans are good as an overwinter legume crop on our wet and heavy clay soil. Caliente mustard would be a suitable brassica crop for our area, and sown in the bed you want to plant legumes in the spring. For empty beds where vegetables will not be grown the following year, general winter mixes containing both brassicas and legumes would also be suitable. September would be the month to plant all these crops so order your seeds right away.
More information on green manures in general is available from the RHS and from greenmanure.co.uk who also have a good range of reasonably priced seeds.