September is one of those lovely in-between months. Summer hasn't quite packed its bags, but autumn is definitely starting to creep in. The mornings feel different, the evenings are drawing in and the garden begins to change gear.
There's still plenty to harvest, but September isn't only about gathering what's already grown. There are salads and oriental leaves to sow, herbs to bring indoors, hardy flowers to start for next year and all sorts of jobs that will keep the garden going for quite a while yet.
For me, it's a month for noticing what's changing, making a few adjustments as the season turns and deciding what comes next.
You’ll find the full list for September sowing in the Easy Seed Planner.
🥕 Vegetable Highlights
Sow outside: spinach, chard, corn salad, winter lettuce, rocket and oriental greens for autumn and winter cropping.
Sow under cover: mizuna, salad rape, mustard greens and spring cabbage.
Plant out: spring cabbage, kale, winter lettuce and late cauliflower.
Tip: keep young plants shaded and well-watered as it’s often warmer and drier than you’d expect.
Veggie jobs this September…
• Keep harvesting summer veg such as beans, courgettes and tomatoes.
• Clear away crops as they finish and add the remains to your compost heap.
• Sow green manures where beds will be empty for a while.
• Earth up leeks and celery.
• Lift onions and shallots to dry before storing.
• Cut back yellowing leaves on brassicas and check for caterpillars.
• Keep watering autumn salads and late crops in dry spells.
🪴 Herby Highlights & Things to Do
September doesn't have to mean saying goodbye to fresh herbs. Some will happily keep going outside for a while yet, while others can be sown or moved under cover to keep fresh leaves coming as the weather changes. It's also a good time to look beyond the herbs we automatically reach for and try something a little different.
• Harvest herbs for drying or freezing while there's still plenty of good leafy growth.
• Pot up a few herbs like parsley and chives to bring indoors.
• Cut back mint and lemon balm hard; they’ll regrow fresh next year.
• Take cuttings of rosemary and sage for new plants.
• Sow coriander and chervil for fresh autumn leaves.
• Tidy herb beds and remove old, woody growth.
🌻 September Flower Jobs
• Sow hardy annuals such as calendula, cornflowers, nigella and poppies for next year.
• Don't be too quick to clear everything away. Seed heads can be beautiful in their own right, provide food for wildlife too.
• Deadhead to prolong colour for as long as possible.
• Divide overgrown perennials and replant the healthiest clumps..
• Plant spring-flowering bulbs in borders and containers.
For more options, filter the flowers by sow in September in the Easy Seed Planner.
🍓 Fruity Goings-on
• Pick late raspberries, blackberries, apples and pears.
• Prune summer-fruiting raspberries once picking is finished.
• Remove old fruit from trees to prevent disease.
• Water young fruit bushes if the weather’s dry. It’ll help root growth before winter.
• Mulch around trees and bushes to lock in moisture and feed the soil.
🧹 Harvest, Store & Tidy
• Keep weeding. Those last few weeds can drop a lot of seed.
• Store potatoes, onions and squash somewhere cool and dry.
• Tidy greenhouses and clear out tired tomato and cucumber plants.
• Ventilate on warm days but close up early evenings to keep the heat in.
• Start collecting fallen leaves for leaf mould. Black bags or wire cages both work well.
• Turn and cover compost heaps to protect them from heavy autumn and winter rain.
• Mulch empty beds to protect and feed the soil through winter.
• Give hedges a trim once you're sure there are no active nests.
• Check water butts and guttering ready for autumn rain.
• Tidy your seed packets and make a note of what worked particularly well this year.
🍁 Making the most of September
September isn't quite summer and it isn't quite autumn either, and perhaps that's what makes it such an interesting month in the garden.
While you're clearing one crop, you can be sowing another. As something finishes outside, something else can be brought under cover. And while you're enjoying the last of this year's flowers, you can already be sowing some of next year's.
So don't be too quick to think the growing season is over. There's still plenty happening if you look a little closer.
And if you fancy trying something a little different this month, take a look at the Easy Seed Planner and our September Offers. There's more to sow in September than you might think.
