What to sow & do in the September kitchen garden

The September kitchen garden is still busy, with some food plants coming to the end of their productive cycle and others finally getting into their stride.

It’s a time for harvesting, tidying up, making preparations for winter foods, and doing some work now so that there’s something to eat next spring during the ‘hungry gap’.

Many kitchen gardeners and allotmenteers have been hampered by heatwave and drought conditions over the last few weeks, but there seems to be some rain in the September 2026 forecast, which might help.

Seeds to sow in September

Some of the seeds you can sow this month will give you a quick crop before the cooler weather sets in, and others will provide slow growing crops over winter or start sprouting next spring.

Some of my favourite places to get seeds and small plants include:

• Dobies – great seed catalogue from long-established company
• Marshalls Garden – good variety of seedlings and plants
• RHS – good for ‘Garden Merit’ tried and tested varieties
• Suttons – lots of 99p seeds and handy advice for beginners
• Thompson & Morgan – all kinds of seeds, strawberry plants, fruit bushes etc
• Wilko – the bargain seeds are back, plus lots of multi-buy offers

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Here are the seeds you can sow this month:

• baby leaf salad
• cavolo nero / Tuscan kale
• chard (white stem varieties)
• ‘green manure’ plants
• Italian rabe /raab (quick growing types of greens)
• leaf beet and perpetual spinach
• mustards (hardy types)
• other oriental greens like pak choi, choy sum and mizuna
• radish (last few quick growing summer types)
• rocket
• spinach (short-day varieties)
• spring onions (such as Ishikura, Winter Hardy White Lisbon)
• winter lettuce (such as Valdor, Winter Density)

Check individual seed packets to make sure you’re sowing September varieties, and that they’ll grow in the area you live in.

You can also try starting off a few extra winter salads such as lamb’s lettuce (also called corn salad), some types of endive, and land cress, either outdoors or in an unheated greenhouse. There’s still time to start off most soft herbs for your windowsill, and maybe some indoor salad, baby leaf spinach and pea shoots too.

There are also plenty of garden jobs to be getting on with.

Garden jobs to do in September

1. Planting out in September

• Biennial herb seedlings (chives, parsley)
• Seedlings or clumps of perennial herbs
• Japanese overwintering onion sets
• Other winter onions and shallots
• Garlic cloves
• Spring greens and Spring cabbages

2. Vegetable care in September

• Bring in winter herb plants for use indoors
• Cut asparagus down to ground level and mulch it
• Divide and lift perennial herbs such as mint
• Earth up and/or stake large winter brassicas
• Get rid of potato foliage (haulms) if blight threatens
• Harden pumpkins for 10 days after cutting
• Feed leeks a balanced liquid feed
• Ripen tomatoes indoors if weather turns bad
• Lift Witloof chicory and place in sand for forcing

3. Care of fruit in September

• Cut old summer raspberry and blackberry canes back after fruiting
• Tie in new summer raspberry canes for next year’s crops
• Fit anti-moth grease bands to fruit tree trunks
• Remove mildewed growth from gooseberries
• Finish any remaining summer pruning
• Prepare ground for fruit tree planting

4. General jobs to keep on top of in September

• Be prepared to protect crops if frost threatens
• Sterilise and store used pots, canes, plant labels etc
• Cover areas of bare soil
• Get composting areas ready for lots of new materials
• Keep the garden tidy to aid pest control
• Save seeds

My September kitchen garden diary

September’s a good month for getting some of those extra crops prepped for the freezer. We’re still picking lots of tomatoes, courgettes, and cucumbers, but as the temperature cools these will start to tail off. So, lots of cucumber salads and a few dill pickles to eat now, and the rest will be cooked and saved for later.

The plan is to get some more winter salads going too, including a last sowing of rocket, quick-growing radishes, some chard (pick some as baby leaves, let some grow on) and mixed mustard leaves. We’re still technically under a hosepipe ban here, so I probably won’t overdo it.

I’m determined to make a proper effort to tidy up in September 2026, whatever the weather.

Our unexpected pests of the year were not aphids, snails or pigeons. No, we’re dealing with a couple of incredibly bold squirrels that have taken a liking to our crops. They’ve finished off all the autumn raspberries, chewed through three cucumbers, and finally they’re now picking and chomping on the tigerella tomatoes.

I mean, have you ever seen a squirrel eating a tomato? It’s right up there in our top five weird kitchen garden moments of all time. Will try to get a photo to add here, but they’re quick little blighters.

 Enjoying this article? You may also like:

• What to sow & do in an August kitchen garden
• British seasonal food in September (what to pick this month)
• What to sow & do in an October kitchen garden

Are you growing your own fruit, vegetables or herbs this year? What’s happening on your plot at the moment?