As a new garden in development, there are recently cleared patches which haven't yet been planted up but shouldn't be left bare overwinter. Green manures help suppress weeds, prevent nutrients being washed away in the winter rains and add essential plant material when dug in. But what to sow?
Hungarian Grazing Rye (secale cereale) is considered by many pundits as the best plant food for any soil, retaining the nitrogen already present in the soil. Hardy, this will grow about 38 cm tall if sown now (August/September) or about 20 cm if sown no later than mid October providing lots of plant material to add to the soil.
After harvesting your potatoes or other crops, the ground should be dug over, raked level and sown at 28 g / sq.m. Or in furrows (rows) spacing the seeds approx 8 cm apart, covering up as you go. Important: dig in the bulk of green material before April ends otherwise the beneficial effects will be lost to verdant new growth.
Winter Tares from the pea family absorbs nitrogen from the air and stores in its roots. Sow from August to the first week in October every 2.5 cm in rows 15 cm apart. 16g will cover approx 1 sq.m. Again dig in during March and April.
For heavy soils, Winter Field Beans (vicia faba) deep roots penetrate and break up the soil. Sow from September through to November, at 20g / sq.m, at 20 cm spacing. For small gardens these can serve a similar purpose to broad beans and provide a delicious crop in spring (more numerous but smaller pods and beans).
Do not follow either of these with more peas or beans as these are from the same family.
The best choice for small gardeners is possibly Red Clover Trifolium pratense. Very fine seeds; 28 g will cover 10 sq.m. Mix the seeds thoroughly with bonemeal or silver sand, which will show up against your soil so you can see where you have broadcast the seed. Can be dug in at any time.
Once sown with turnips after harvesting grain to feed sheep let out on the stubble in spring.
Fast growing White Mustard (sinapis alba) thinly broadcast before mid-September can be dug in during October or left to die off in the cold weather as a mulch. Also can be sown April to August to dig in that season. Do not use if intending to grow brassicas in that area to reduce incidence of clubroot.
So lots of choice - I need to look at my plan to see what best suits the crops or plants which will follow.