The City Gardener: The darling buds of …. September?

Spring may be flashier, but the September garden has more soul.

Published Sep 04, 2026  •  3 minute read

September is the perfect time to give your garden a nice sprucing-up. SHUTTERSTOCK

September is my favourite time in the garden. It’s not quite so hot, the garden is usually gratifyingly lush and full, and it’s a great place to just stretch out with a book (or, it being 2026, my phone), and just chill.

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September marks another milestone as well, since it’s the perfect time to walk through your garden and take a close inventory of what needs doing. If the spring is for building up the garden, you might think of September as akin to renovating.

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Cooler temperatures are great for planting and moving things; when it’s really hot, everything tends to go to sleep, which can retard the recovery and growth process.

Plants that may have enjoyed full sun in the spring but ended up sun-starved when the trees filled in, or are just in the wrong spot, can safely be moved now.

Refresh compost or mulch that’s been displaced by rain or critters. Remove dead plants (or parts of plants), spent annuals and other debris, along with deadheading any flowers you missed before. I use broken pieces of old flagstone to line my beds; by now they tend to have shifted around a bit, so I’ll take an afternoon and neaten them up.

Look for bare spots between plants that are perfect for either planting something newly purchased, something you’re transplanting from elsewhere in the garden, or pieces of plants that you’ve divided.

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Overgrown or unshapely plants can be cut back. I tend to cut back my ditch lilies (that is, species daylilies) to about twelve inches or so; by September they tend to look pretty ratty, and they don’t seem to mind being trimmed.

Now for the fun part. There are lots of easy-to-grow, reliable performers that come into their own now for adding fresh colour to your late summer and fall garden. A trip to the local garden centre will give you lots of ideas, but here are a few of my favourites.

Japanese anemone is under-appreciated by many Canadian gardeners, but given the right conditions (including full sun), it produces a profusion of white, pink, cerise or lavender flowers in late summer, when other perennials are winding down. The blossoms remind me a little of single-petal peonies, and they’re almost as hardy once established.

Aster, or Michaelmas daisy, adds a pretty shot of blue-purple to go with the vibrant yellow of black-eyed Susans, goldenrod (both of which are technically weeds, but which I happen to love), and sunflowers.

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Fill in bare spots with instant colour from celosia, zinnias, marigolds and other annuals. And of course, mums can either be planted in the front of the garden or plopped, pot and all, into your urns or parading down your front steps.

Flowers are not the only source of colour for your late-summer garden. The thick, colourful leaves of ornamental cabbages will see you right through to the first frosts.

And don’t overlook grasses: annual fountain grass, with its striking red-to-purple stems, can take its place alongside perennial grasses that are starting to turn wheat-yellow.

Along with the satisfaction it gives us human gardeners, zhuzhing up your September garden has another, perhaps even more important effect.

Birds and beneficial insects are preparing to migrate, or putting in a last burst of productivity before winter closes in, and you’re offering them a cornucopia when they need it most. That’s good for your soul, for their survival, and for the planet too.

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