What To Do In The Garden In September

“Some of the rarest days of the year come in September, days when it is comfortably cool but pulsing with life.”  Although the cool part is only really true now as we enjoyed a gloriously unseasonal heatwave during the first few days in September this year. And although I had a lot more watering to do than usual, our garden in September certainly relished the extra heat and light. Welcome to this month’s garden update, let’s take a look at what we’re still enjoying here, as well as what to do in your September garden.

What To Do In The Garden In September

As usual, I’ll break my monthly garden update down into sections: flowers, vegetables, fruits, jobs, wildlife, interspersed with my September gardening tips. So, you can skip to whatever section you’re most interested in, depending on what things to do in your garden in September you’re most keen to know about.

The Flower Garden in September

I’ve just realised I used to break my flower section down into Annuals and Perennials – so I’m going to do that again now.

Annuals

Annuals are plants that grow from seed, flower, set seed, and then die, all within one year. Just like these beautiful Cosmos in pots at the front of our house. If you keep deadheading, they’ll keep blooming, they’re great value for money.

Other annuals are like these wildflowers in the wheelbarrow, a happy result of broadcast sowing a box of wildflower seed earlier this year. Tip: “broadcast sowing” is the technical term for chucking seed down any old where when you’re fed up with seed trays and pots.

Other favourite annuals are Malvas, or Mallows, like this pretty pink one in a pot and her taller purple sister in a border. Both self-seeded from their parents in previous years, which is perfect.

Also self-seeded from last year’s plants are these glorious Claret Sunflowers* which are absolutely humming with bees from dawn to dusk. I’m deadheading to encourage more flowers but soon I’ll start leaving the seedheads in place for the birds to feed on.

Last of the annuals and still providing a couple of small scented bedside posies every week are the Sweet Peas* in the cutting garden. Some have already gone to seed so when they’ve turned brown, I’ll save some of their seeds, ready for sowing into Rootrainers* in November and overwintering in the greenhouse. Tip: Autumn-sown sweet peas grow away faster in Spring as they get their roots down earlier, so you can start picking your flowers earlier the following year.

Perennials

Perennials  are plants and shrubs that die back in Winter and come back again the following year, and you can never have too many of these great value garden essentials. When the weather cools you can divide your herbaceous perennials to increase your plant stock, planting and watering in your new divisions well.

Our two Japanese Anemones are beginning to take over their respective beds, so one of my September gardening jobs will be to divide them both. I’ll replant the one half in the original hole and the other half wherever I have a gap. It stops the congestion and I get new perennial plants for free.

I’ve done this with some of our Lavenders in previous years, to great success. As you can see, our Lavenders have finished flowering, so I’ll be cutting them back shortly, but not into the old wood. When I do, I’ll save some seeds, and also from the delicate papery seedheads of the Lunaria, or Honesty. Technically, Lunaria is a biennial (flowering in the second year) but I’m not starting a whole new sub-section in this post just for her.

Lighting up some shaded areas are these lovely Asters with their daisy-like flowers. On the left is the mauve Aster Frikartii Monch, the classic Michaelmas daisy, and on the right is Wood Aster with her starry white blooms. Both should keep flowering for at least a couple more months, taking us into November.

Provided we don’t get any frosts, our two potted Fuchsias should do the same. Having left moved them into the protection of the greenhouse too late one year and been left with some dead-looking brown twigs, I’ve learned my lesson. Tip: fuchsia berries are edible – they taste rather like watery cherries.

Sedum Purple Emperors are late-flowering plants that provide nectar for pollinating insects into Autumn. How gorgeous is the striking purple foliage/pink flower combination? Another bee magnet is the purple Knapweed, which comes from the same Centaurea family as the annual Cornflower.

Other very popular plants for pollinators are the blue Echinops and the white Buddleia. The Buddleia has finished flowering now and will need pruning soon, but at the very end of August she was smothered in Peacock and Red Admiral butterflies, which was absolutely amazing to see.

More vivid September garden colour is coming from my gorgeous Penhill Watermelon dahlia with her dinner plate sized pink flowers, and the legions of purple Verbena Bonariensis in the flower bed. Verbena Bonariensis are hardy, drought tolerant, and repeat flowering if lightly pruned, they’re brilliant for splashes of colour and pollinators love them too. Both plants should bloom until the first frosts at least.

I also love these stunningly beautiful pink Echinaceas, and the incredible magenta Rudbeckias, who defied all the odds (Ginger repeatedly sitting on them when they were young plants) to flower triumphantly now.

Other easy to grow perennials are Hydrangeas, such as my favourite Hydrangea by the front door, who’s perfectly happy in shade for most of the day. And Astrantias, once they settle, will give you repeat flowerings of gorgeous starry blooms. Ours seem happiest in a shadier border rather than in full sun.

The Achilleas, or Yarrows, are still giving life to our herbaceous border with their ferny foliage and clusters of colourful flower heads. And the purple Joe Pyeweed continues to tower above everything, adding some interesting height to the planting layout.

Cooler purple tones like the lovely Geranium Rozanne, Geranium Nodosum, and Clematis drawing the eye away from an ugly downpipe are brightening up some of the shadier parts of our September garden.

And three of our Roses are flowering again, providing a fragrant and colourful display. Tip: it’s time to prune climbing roses and rambling roses, but only if they’ve finished flowering for the year.

The Vegetable Garden in September

My experiment with Companion Planting in our new vegetable bed has gone really well this year. We’ve been harvesting plenty of Courgettes* and French Beans* for weeks now. I’ve just harvested our first Sweetcorn* too. Tip: once the tassels go brown, if you can pop a corn with your thumbnail and the juices are milky, they’ll be perfect. And indeed they are, not as uniformly sleek as shop-bought cobs, but ours are just BURSTING with natural sweetness and crunch 🙂

Our olive-sized Cucamelons* (they taste like cucumber with a hint of lime) are cropping heavily now, and we’re picking a few Lettuce* leaves every day for our sandwiches. Tip: keep your Lettuce under cover, or in a greenhouse, so the pigeons don’t help themselves.

Over in our original glass greenhouse and our new-this-year plastic lean-to greenhouse*, our little ‘Rainbow Blend’ F1 Hybrid tomatoes* are ripening at last. I mentioned last month that I’d painstakingly applied white shade paint* to the outside of our original greenhouse, to prevent it from overheating in sunny weather. And then of course we had a washout August. But cutting away all the plants’ leaves did help with air circulation and light distribution. I won’t be removing the shade paint this Autumn though, as enough light can still get through for whatever I decide to sow, grow, and overwinter in the greenhouse.

Meanwhile, over in our kitchen garden or potager garden (where you grow herbs in among your flowers, fruits, and vegetables), our lovely aniseed-scented Fennel is going to seed. Once these all turn brown, I’ll collect some to use in cooking before I cut back all the stems. And the self-seeded Wild Spinach with its pretty purple flowers in among our flowering Sweet Peas is still providing plenty of leaves for our salads.

I’d normally keep edible flowers in the Flower Garden section of this garden update, but there are already so many in there (!) I thought I’d move them to the Vegetables section this month. So, we have vivid blue colour from our Borage (great in ice cubes) and our clove-spiced Cornflowers…

And zingy peppery heat from the pink Nasturtiums along with calming creamy Calendulas. All these edible flowers make wonderfully colourful and decorative additions to cakes and salads.

The Fruit Garden in September

Rhubarb season is supposed to be over but our plants are still going strong – just enough to make one last batch of delicious rhubarb and ginger jam, I think. Taking care not to disturb the snoozing cat guardians, of course. And there’ll be plenty of Grapes on our grapevine for the birds as usual too.

Meanwhile, we’re savouring the last of our Blueberries, Blackberries, and little wild Alpine Strawberries while we can. Tip: create new strawberry plants for free by pegging down any strawberry runners into pots of compost to set roots – they only take a couple of weeks to get going.

Over on our fruit trees, we’ve had plenty of Apples, too many in fact, we’re leaving the windfalls for the wasps and birds. Our Pears aren’t quite ready yet though. Tip: gently lift them and give them a little pull, or twist their stems a couple of times – if they’re ripe, they’ll come away easily.

Although we only had a handful of Plums this year, our Fig tree has been prolific, there’s no way we can eat all the fruits. So I like this tip about bottling spare Figs in vodka. Then they can be sliced to serve as a delicious pudding topping and you can drink the spirit as you would Sloe or Damson Gin.

Last but not least, some of the fruits on our little Physalis, or Cape Gooseberry, are nearly ready to harvest. The green casing has turned brown and it looks like the fruit inside has ripened to orange. Tip: this was a “Reduced Plants” find and nearly dead. I soaked it in a bucket of water for 48 hours and potted it on, and look at her now.

Gardening Jobs To Do in September

Gardening in September means continuing with dead heading to encourage new blooms, tying in new growth, moving around plant supports as necessary, and watering any garden plants that seem droopy.

Is it worth planting flowers in September? Yes, absolutely, now’s a great time to sow your hardy annuals such as Cornflowers, Lunaria, Amni, Scabious, Coreopsis, Poppies etc, so they can get their roots down while the soil is still warm. That way you’ll get a burst of colour earlier in the season next year.

One of my favourite September gardening jobs takes place indoors – choosing my Spring flowering bulbs for planting this Autumn, for lots of lovely Spring colour next year. I already have 100 x Crocuses, 100 x Tete-a-Tetes, 170 x Muscari, and 25 x Iris Reticulata to plant over the coming weeks. And I’ll be ordering some more Alliums shortly too 🙂 Bulbs are brilliant, once they establish they come back year on year with no further effort required. Cheap colour for almost zero outlay – what’s not to love?

After we came back from our 2 week August holiday, Alan had to cut the grass twice – the first time on a higher setting to trim it back, then on a lower setting a few days later. Unbelievably, we STILL have gazillions of baby frogs jumping around everywhere, so he’s mowing v e r y  s l o w l y  to give them plenty of time to get out the way.

We’ve also started to collect the fallen leaves, which we split between our compost bins and biodegradable leaf sacks* to rot down into leaf mould. This is a brilliant – and free – soil conditioner for your garden plants.  Although we’ll still leave a few leaf piles in corners of the orchard, for the hedgehogs to have somewhere to hibernate safely (of which more later…)

Lastly, a tip for your houseplants and indoor plants.  If you haven’t done so already, bring them back inside before the nights get too cold.

September Gardening For Wildlife

Our two bee houses or bug hotels* for solitary mason bees and any other insect that needs a home are full now. And Alan is keeping our garden bird feeders topped up with quality wild bird food* and high energy fat balls* on a daily basis, to build up the birds’ strength before Winter.

As regular readers will know, our ponds are home to lots of frogs and newts – honestly, just how cute are these babies?

If you’re looking for ways to encourage and support wildlife, here are some easy tips to make your garden more wildlife friendly, and some suggestions for how to create a butterfly garden in the smallest of spaces, such as a window box or balcony.

Despite all this, I have to confess one of the things I don’t like about the approach of Autumn is just how many spiders have set up home in our garden. All their webs seem to be at head height or knee height, and I’m forever brushing cobwebs off me. I’ve been bitten a few times too, and while our garden spiders may not poisonous, their bites HURT!

Lastly, I’m so thrilled to share that we have a resident hedgehog! We met him as we were leaving at 02.00am to head to the airport last month, and he was whiffling around outside our front door. 🙂

Our Garden In September

And that concludes my ninth garden post of 2023 – wow, time flies. I hope you enjoyed my garden round up, and found it a useful guide and reminder of things to do in your garden in September. Next month, in my October garden update, I hope we’ll still be enjoying plenty of flowers, and I’ll be starting to look ahead and plan for early Winter too.

Did you enjoy your virtual visit to our September garden and orchard? Which were your favourite photos or top tips? Have you been enjoying your outside space this month too?

* This post features affiliate links but all opinions are my own (see my Disclaimer).