Gardening Jobs for September

The tail end of summer brings late sun, allotment hauls and garden maintenance before cooler weather arrives. Here are those all-important gardening jobs for September.

In the garden

Plant for autumn (and spring) colour

As your summer blooms die back, you may be wondering what to do this month. Answer: it’s time to get prepped for the seasons ahead. Plant up your borders and containers with colourful autumn bedding like heather and cyclamen that will keep your garden looking swish and keep your pollinators well cared for. September’s also the time to start planning for spring bulb displays, so get your daffodils, crocuses and tulips into pots and beds to guarantee greatness.

Poppy seed heads
Poppy seed heads

Lift and divide perennials

Once they’ve finished flowering, dig up and karate chop the rootballs of any herbaceous perennials that are becoming too big or congested. Dividing clumps in two will keep the plants healthy and leave you with extras to fill out your beds or share with pals.

Dividing perennials is a task you only need to do once every two or three years. Lift the clump out of the ground with a fork and use a machete (or the bread knife) to cut through the root ball. Replant the divisions and water them in well to make sure they survive the chop.

Move houseplants inside

Move any indoor plants that have been summering outside back into the house before the temperature drops too low for their liking. Now is also a good time to do some general houseplant maintenance, removing any straggly blooms or wayward foliage so they look their best back inside.

Wiping down a plant with a cloth
Wiping down a plant with a cloth

Take some cuttings

Tender shrubs and herbs can easily be damaged by winter weather, But by taking what are known as ‘semi-ripe’ cuttings now, you’ll have a host of young, healthy specimens as backups in case the worst does happen. Rosemary, lavender, fuchsias and salvias are all easy to grow from cuttings.

Snip a non-flowering stem (about 10-15cm long), pull off the lower leaves and cut off the very tip of the stem just above another set of leaves. Fill small pots with peat-free cutting compost (this is usually potting compost mixed with perlite or sand) and water them well before making a little hole in the top of each one and planting a cutting inside. Cover the pots with a plastic bag or put them in a propagator and keep them well-watered (but not excessively wet) until they take root.

Trim hedges

Neaten up your conifer and box hedges by giving them a haircut this month. This will help to control the height and add pleasing clean lines to your garden. If you’re an absolute perfectionist, or you’re crafting a topiary masterpiece, you might want to use a pair of shears to do the finishing touches.

A gardener with shears, trimming a bush
A gardener with shears, trimming a bush

On the allotment

Enjoy a fruit fest

Tis’ the cockney rhyming season. Apples and pears are ready from now, so don some scrumping clobber and fill your boots. Autumn raspberries will be making an appearance about now too. Fruit tarts and home preserves ahoy! Time to dig out the jam pan…

Raspberry bush full of fruit with a bowl full of raspberries
Raspberry bush full of fruit with a bowl full of raspberries

Harvest your veggies

When you have an allotment, every day in September feels like harvest festival. Tomatoes, aubergines, potatoes, peppers, onions, beans. They just keep…appearing. Keep picking regularly to keep to last of it coming. Trusses of tomatoes can be removed on the vine and left to ripen indoors if you’re worried that the weather might turn quickly.

Don’t skimp on watering

What with everything else happening on the plot, it can be tempting to neglect the basics. But keep watering everything regularly to make sure it all ripens before the season turns.

Close up of a watering can with water coming out of it
Close up of a watering can with water coming out of it

Blitz the greenhouse

At the end of a long season, greenhouses and polytunnels can end up looking pretty sorry for themselves. Clean things up by removing spent plants, chuck out the empty bottles of tomato feed and recycle your broken plant labels. Wipe away the slug trails, hose down the windows and restack the pots to create an illusion of calm before the next frenzy begins.

Keep sowing seeds

As crops go over and beds get emptied, sow some green manure like phacelia, crimson clover or ryegrass over them. This will hold back the weeds and can be dug into the soil in spring, where it will add nutrients and improve your future crops.

In terms of tasty things to eat, kale, pak choi and winter lettuce can be sown now, to keep you in delicious salads all winter long.

Someone with their hands open with seeds on their palms
Someone with their hands open with seeds on their palms

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