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What’s in Bloom? September at RBG

August 30, 2023

What Blooms in September?

Note: this is a general guide of what typically blooms this month at RBG. Bloom periods may vary by up to 2 weeks. For the best view of what’s blooming right now at RBG, see the current photos on RBG’s Instagram, or find the “Bloom Watch” section on the What’s in Bloom page.

September is a beautiful month of transition in the gardens, as blooms are joined by fruiting plants and autumn colours begin to tint the canopies. 

At Rock Garden, fall colours slowly trickle in, with the Japanese Maple tree as fiery standout in the lower bowl. More blooms continue to flourish, including Cardinal Flower, Snowdrop Anemone, White Wood Aster, Joe-Pye Weed, Goldenrod and Lesser Calamint, all complimented by the collection of richly green coniferous trees. While Hibiscus pass peak bloom, many still provide stunning displays of colour and grandeur.  

Enjoy some downtime and serenity down by the water feature, where Waterlily blooms over calm waters, and ornamental grasses including delicate Purple Love Grass and the fuller Tufted Hair Grass make a captivating backdrop with the setting sun.

  • Bright pink hibiscus blooming
  • Goldenrod Goldking
  • Three white water lily blooms bursting from a still dark pond, surrounded by lily pads
  • Phellodendron Amurense Leaves Turning Yellow

Pictured, left to right: Hibiscus, Goldenrod. Water Lily, Phillodendron Tree

Over in Hendrie Park, the Helen M. Kippax Garden bursts with pollinator-friendly native plants and their cultivars, including Coneflower, Aster and Goldenrod. Flowering herbs complement fruiting plants of all kinds in Veggie Village as gardeners complete the fall harvest.

In the Rose Garden, individual late-season Rose varieties continue to pop throughout the month! Between the Rose blooms, spot striking companion plants like Stonecrop, Lindheimer’s Beeblossom, and Verbena bonariensis. 

  • verbena blooming along the rose garden pathway
  • sunflower
  • orange roses
  • purple aster and goldenrod

Pictured, left to right: Verbena, Sunflower, Rose, Aster & Goldenrod

At the Arboretum, full trees offer shade for those exploring the wide-open garden; watch the changing colours of the Maple, Oak and Linden trees as we move further into fall. Keep an eye out in the Synoptic Shrub Collection for Beautyberry, a fantastic fall shrub with richly coloured purple fruit, and the Seven-son Flower for their wonderfully scented blooms.

The first burst of fall colour begins along the trails, led by Goldenrod and over 30 species of Aster, with flowers concentrated around Princess Point, the Arboretum and Rock Chapel. In the wetlands, marsh plants, including Blue Vervain, Pickerel Weed, and Cattail flourish. 

  • White flowers of Heptacodium miconioides (Seven-son Flower)
  • purple jewel tone clusters of berries along a thin tree branch
  • Grouping of small white aster blooms
  • Cattails in the foreground, with a wide marsh in the background

Pictured, left to right: Seven-son flower, Beautyberry, Aster, Cattail

Laking Garden closes for the season after the Labour Day long weekend. September 4 is the final day to visit this charming garden!

September Favourites

Late summer red rose blooming in Hendrie Park

Roses

The rose collection features multiple flushes mid June through fall, alongside companion plants that bloom throughout the season. 

The Rose Garden is located in Hendrie Park.

two monarch butterflies on blazing star blooms

Rock Garden Perennials

The rejuvenated David Braley and Nancy Gordon Rock Garden contains many bold drifts of herbaceous perennials, with peak interest from July through September. 

Plants that typically flower / Plants of Interest in September at RBG

  • Anise Hyssop
  • Annuals
  • Aster
  • Black eye Susan
  • Blue Vervain
  • Butterfly Bush
  • Cardinal Flower
  • Coneflower
  • Goldenrod
  • Hibiscus
  • Hosta
  • Hydrangea
  • Japanese anemone
  • Joe-Pye Weed
  • Lindheimer’s Beeblossom
  • Mountain Fleeceflower
  • Phlox
  • Pickerel Weed
  • Rose
  • Sage
  • Seven-son Flower
  • Snowberry
  • Spurge
  • Sunflower
  • Sweet-Amber
  • Waterlily

*These plants have short bloom times and are very weather dependent. Check our social media feeds closer to bloom time for updates. 

Blooms by Season

Plants of interest are ever-changing in RBG’s five cultivated garden areas and nature sanctuaries. Learn what’s blooming now or see the blooms calendar for a rough estimation of what to expect each season.