What to Do in The Garden in September

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what to do in the garden in september

It’s September already. How did that happen? 

It’s been a wet and dull summer for the most part and the effect is obvious in the garden where my veggies are behind. 

That said, it’s still a busy month, so here’s what you could do in September.

What Vegetables to Grow In September

It’s harvest time! 


This is really the final few weeks we have to ripen tomatoes. It’s a good idea to cut off foliage covering any tomatoes and remove flowers or small fruits. This helps ripen up the larger fruit. Keep watering!


Sweetcorn and Beans

Sweetcorn is ready when the ‘hair’ goes brown, so harvest them before the squirrels get in there. 

Beans will keep producing until the frosts so water, feed and pick, pick, pick. Freeze what you can, they taste just as good for Christmas dinner as they do now. 

Main Crop Potatoes

If your main crop potatoes have flowered, cut the foliage to ground level and leave them for a few weeks before digging up as this prevents blight and allows the spuds time to toughen their skin for storage. 

If you’re not eating potatoes right away allow them to dry and store them in a hessian sack or paper bag. Ensure they aren’t touching just in case there’s an infected one lurking. Check them every week and throw away anything that looks mouldy, scabby, or soft.  

Carrots and Beetroot

My carrots are still tiny so I’m going to leave them in for another few weeks. If you’ve got some finger size roots eat them up before the weather turns or the skins go leathery. Same goes for beetroot


I didn’t grow any pumpkins this year. Actually, I tried but they were decimated by all the slugs I’ve attracted. So many this year! 

Next year I’m going to try growing them up. If you’ve grown pumpkins or squash remove any leaves that are shading the fruit to help ripen up the gourd for Halloween.

Hedgerow fruits

It’s blackberrying time.

It’s a September rule in our house to head out to the hedgerows with a Tupperware. 

Kids love picking blackberries and they are ready to start picking now. Look for bushes in the sun as these blackberries are sweeter, but do leave some for the birds. 

I’d recommend reducing blackberries with a few cooking apples to make a crumble – unless you’re going to eat them raw with ice-cream which is just as good.


Fruit Trees

And speaking of cooking apples if you have any fruit or stone fruit trees then September is a good time to harvest apples, pears, plums, or quince. 

Gently twist the fruit and if it comes away easily it’s good to go. Store apples and pears in wooden crates or hessian sacks, but like potatoes don’t allow them to touch in case a bad fruit infects the lot.

What to Do With Flowers in September

Don’t give up – flowers will keep coming until the frosts.

Roses may have a final flush this month so keep watering and feeding them. You can prune your climbing roses now. 

Climbers grow on next year’s stems so cut them back to a foot or so. Ramblers grow flowers on this year’s growth. It’s best to prune ramblers when the flowers are spent so they have time to regrow new stems to flower on in 2022. 

Your hanging baskets will keep going until the frosts so keep watering and feeding them. 


When your sunflowers have finished flowering leave the heads in situ for birds to harvest the seed. Or you can cut the head and put it on a bird table. Finches and tits as well as blackbirds and robins love sunflower seeds. 


Perennial Plant Trims

Keep cutting off seed heads and if the weather is bright and warm you might get a new flush of flowers.

It’s also a great time to divide herbaceous perennials. They grow so much better when they’ve been revitalised in this way. 

If you have any clumps that are too large or look dead in the centre dig them up and slice down the centre with a sharp spade – then replant! It’s a very easy job and you get a whole new plant for free. 

You could quarter the clump instead, just cut back foliage after dividing and water it well as the plant needs all its energy to get its roots going again.


September is a good time to plant all manner of bulbs – daffs, crocuses and hyacinths can all be planted now. It’s best to wait until late October for tulips though. 

Use a sharp trowel or a bulb planter and put the bulb in a few inches below the soil with the pointy end up. 

If you are planting a swathe, it looks more natural to gently roll them along the ground and plant where they end up. This avoids the military precision of a row. 

What to Plant in September

As well as bulbs, there’s still time to sow wallflowers, sweet williams, and wildflower seeds. They won’t flower until next year but need to start growing now. 

Rainbow chard is a pretty autumn vegetable you can sow now. I’ve popped in a few plug plants for a head start. You could also put in turnip, sprouts, spinach, and onion sets which will all mature over winter and be ready next spring. 

If you grow under glass or a cloche pop in some winter lettuce and keep it well watered. 


Woody shrubs take good cutting right now. Here are my tree mallows – these pink giants were last year’s foot long cuttings.

pink tree mallow

Tree mallows are a great investment because you can make numerous free plants! Just snip below a nodule and push it into the ground or a pot of compost. When it grows new leaves, the new plant is ready.

How to Tend to Your Lawn And Hedges in September

September is busy time for the lawn. Keep mowing when it’s dry because you never know when the British rainy winter will begin.

Rake out moss and thatch and reseed bare areas. Early autumn is a good time to reseed as the temperatures are still warm but it’s not boiling (did we even get boiling this year?)

If you haven’t used one before I recommend a scarifier to get all the dead plant material out so the grass can breathe and soak up water. Failing that, a good hard raking. 

How to Help Out Wildlife in September

September is a busy month for pond owners. Now is the perfect time to net early falling leaves and deal with algae overgrowth before the main leaf fall takes over. 

Leave algae debris pondside for 24 hours so the pond life can crawl back into the water and keep an eye out for frogs, toads and other amphibians who will be searching for a place to hibernate in the pond’s vicinity. 

A log pile beside the pond or a few old paving slabs propped up on a brick is perfect if you’re looking to help them out. I was given a frogilow – a ‘frog bungalow’ for my birthday. So far, it’s only attracted ants and slugs, but I’m hopeful and it looks cute in the meantime. 

My little bucket pond is a new addition this summer but it’s full of algae which I’ll be removing soon. I’m going to fit a row of mini bucket ponds along this wildlife section of my garden in my quest to attract dragonflies. 

Algae filled bucket pond

You might also see hedgehogs in September. Late litters are common so keep putting out water and cat food to fatten up the little hogs in time for hibernation. 

If you see one outside in the day time it’s probably in trouble and needs a wildlife centre or vet’s attention. If it’s a big hog, in a hurry, with a mouthful of leaves or similar leave that busy mum be. 

You could help out with a hedgehog house for winter’s hibernation. I’ve made mine, but they are about £35 online if you’re not handy in the shed.

hedgehog house

How to Deal With Garden Pests in September

The pests of August are still around so keep an eye peeled for aphids, blackflies, slugs and snails. 

September fungus and infected spores like bacterial canker tend to get hold around now because the air is damp and there’s not so much heat to dry plants out. 

Cut back foliage to tempt in air circulation and remove any infected plants as soon as possible. My rhubarb is getting a bit of mould on the older leaves so they’ve come off. 

Tending to Patios, Decks, and Garden Furniture in September

Before the rain and frosts arrive get your decking and wooden furniture in order! 

If you have a helpful child relative you could pay them to paint on decking oil as I did here – worth it! 

child painting decking oil

Use a pressure washer or tough scrubbing brushes to get algae or bird mess from your wood and oil it up so the rain doesn’t soak in and rot the wood over winter. 

I’ve been using a cordless battery powered pressure washer for my rattan furniture and its great with a squirt of washing up liquid. 

The Most Important Job in September?!

Sit outside.

It’s warm in the garden so I’d recommend heading outside every chance you get to soak up the sun while you still have the chance. 

You can’t beat warm autumn sunshine. It warms up your bones and makes the world a better place. 

Enjoy your September – it’s an interesting month to sit and watch nature gradually change into her winter attire and begin to get ready for winter’s hibernation. 

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