Vegetables in September

September is kind of like a second Spring—the late summer sown crops establish quickly with warm soil temperatures and usually plenty of moisture around for newly planted crops to get going quickly. September growth is often lush like it can be in Spring and it is a great month to make the most of these conditions.
We planted lots of chicory, turnips, fennel, salad leaves and autumn cabbage through August and will continue lots of salad and leafy green sowings through the beginning of September to be planted in our polytunnels from the end of the month and through October. These crops will replace summer veg such as tomatoes, cucumbers, french beans and peppers that are coming to their end by mid October.
We usually just hoe off old crops in the polytunnels and then water the beds thoroughly for a few hours before raking out the beds and planting straight into them. Some of the crops with thicker stems like tomatoes might need chopping off at ground level or just below. Doing it this way means that the roots remain in the soil with all of the solid life remaining intact, rather than pulling up the plants with all of the associated microorganisms around the roots being disturbed.
Planting new crops into relatively undisturbed soil like this means that the plants’ roots can quickly make new associations with the soil life and access more nutrients to grow healthily.
Something else that we have begun to do from mid August and through September is to sow green manures over our autumn growing crops outside. So, after planting things like fennel, endive, lettuce, salad leaves and chicory we hoe them about a week later, and then about a week after the first hoeing we broadcast or direct drill green manures and then hoe them in to incorporate them into the top layer of soil.
We use a mix of things for this but it usually consists of black oats, linseed, phacelia and buckwheat amongst other things. Having a mix of different species ensures different rooting depths and different associations with soil life. Some of these will be winter killed whilst others will slowly grow through winter, covering the soil and providing living roots so that microorganisms can live off the exudates given out by the roots, and in turn provide accessible nutrients to the plants. We then mow these down in early spring and cover the beds with black plastic to kill of any crop residue and green manures before planting early crops into the ground.
So, although there is a sense of things slowing down in September and less of a feeling of urgency than there is through the summer, there is still plenty to do, and of course plenty to harvest too.

WHAT TO SOW THIS MONTH: Direct sown outside: turnip greens, leaf radish, red russian kale as salad leaf. Sow in trays: Now is the time to make sure you start sowing all of your overwintering salad leaves if you have a glasshouse or polytunnel, or even a sheltered spot on a patio. Leaves such as winter purslane, landcress, rocket, mustards, corn salad, endive, chervil, lettuce should be sown from the beginning of the month through to early October.. Also spring onions for overwintering in a cloche or tunnel/glasshouse

WHAT TO PLANT THIS MONTH:

OUTSIDE: salad leaves: leaf radish, winter purslane, landcress, rocket, mustards, overwintering spring onions, spinach and spring cabbage.

INSIDE: overwintering salad leaves (at the end of the month and into October), chard, coriander, chervil and parsley.

OTHER IMPORTANT TASKS THIS MONTH: Get your squash in by the end of the month and cure them either in a glasshouse, polytunnel or ideally in your house—this will make sure that the skins are hard and will last through the winter.