This is a month of inevitable holes as potatoes are dug up, lettuce bolts, peas comes to a mildewy end and dwarf french beans are picked bare. But the season is not over yet – there are plenty of vegetables that can be sown now in these gaps, to get growth before the days are too short. Days in September can be hotter than August, but daylight is already vanishing, and any seed sown then will struggle to grow before the cool sets in. First, there are the quick germinating vegetables from Asia such as mizuna, mibuna, mustards, choy sum and leaf radishes. These are easy sorts, as good in containers as in the ground. Sow a few batches in modules to plant out in polytunnel beds or pots on patios and in greenhouses once the tomatoes, aubergines and chillies are over. You can do the same for coriander and parsley; both winter well under protection. There is still a week or so left to sow bulb fennel; sown now, these won’t have time to swell into the heavy version you find in the supermarket, but instead you can grow them as baby fennel, so sweet and tender that they can be shaved into salads or caramelised into cooked dishes. If you found your fennel all bolted in this summer’s unpredictable weather, have one final go – this is often the best month for them. Likewise, spring and bunching onions will germinate very quickly in the warm soil. These will then grow evenly over winter. Slugs are fond of these young, sweet onions, so take measures. I find Slug Gone – pellets made from sheep’s wool – are fairly effective, if you make a thickish barrier either side of your sowings. Black Spanish Round is an old variety of winter radish. Raw, it’s too hot for my liking, but cooked it is something else: mild, delicious and with the consistency of swede. Sow now to harvest from the end of October on, when it should be golf ball-sized. But perhaps most importantly, this is the last moment to get your salads sown for winter. Till the middle of August, I sow winter hardy lettuce, mostly in modules to plant out by the end of the month. Varieties such as Navara, Winter Gem (a winter hardy Little Gem that’s tasty and good for pot growing), Winter Density, Valdor or the huge Marvel of Four Seasons are all reliable cultivars for winter growing. If you successional sow two or three lots of these, you’ll be picking lettuce right the way into March. Towards the middle of August, I sow chervil, lamb’s lettuce, rocket, winter purslane and land cress direct in the ground or into large containers near the back door. They’re perfect for those dark evenings when I don’t want to go hunting with a torch to find something to go with supper.