September - "autumn's best of cheer"
Although the focus is bringing in the harvest, you can still sow turnips, winter lettuce and salad greens such as mustards, mizuna, rocket and lambs lettuce to add variety.
herbs - sweet cicely, borage, chervil
Mulch empty patches with garden compost, well rotted manure or straw or even layers of cardboard. Or sow a green manure - clover, trefoil, buckwheat, phacelia, grazing rye, winter tares.
Cornflower, Nigella, Scabiosa, Ammi Majus, Godetia.
Autumn-sown wildflowers seeds generally germinate and establish quickly. They naturally set seed at the end of the summer, although some may not come up until the following spring.
Corncockle, red field poppy, primrose and cowslip .