K, I am calling autumn (I am honestly not alone, whether you follow the meteorological calendar or not). There may, of course, be an Indian summer, but much of growing is more about light than heat, and some of you may see your first frost this month. So start to cloche if you can. Sowing this month is about eking out longer life. There is time (just) to sow spinach, a last scattering of coriander if you have shelter, a few hardy salads, likely the last ‘oriental’ leaf. Time, too, to start planting overwintering garlic and onion, though we have had mixed success – for which read disappointing failure. I am still unsure whether we will try again this year. Howard is not keen. You have, anyway, until October. Howard and Rose are working a nearby plot for his mother-in-law: poor soil in not great light, so they’ll probably sow some green manure. We’ve had success with a mix of vetch, red clover and winter beans. Rye grass and grazing rye are also good to go in this month. Pole beans will likely be coming to an end so keep picking while you can. Many of the ‘tender plants’ – pumpkins, tomatoes, aubergines – will need ripening off now. If all else fails, tomatoes will respond well to a banana in a bag unless you prefer making chutney. Winter squash should be coming on stream. Time to tidy and clear the decks. Though feeding plants is pretty much obsolete now, thoughts turn to soil. Dig out remaining potatoes and onions, remove old planting and top up the compost heap. Start collecting fallen leaf for leaf-mould. September is a housekeeping month. Look after your land and save seed, especially from beans, peas, herbs, corn (more on this next week). It is likely the last month of heavy harvest, so take time, too, to give quiet thanks. Allan Jenkins’s Plot 29 (4th Estate, £9.99) is out now. Order it for £8.49 from guardianbookshop.com