Summer may be winding down, but with the right plant choices a shrub and perennial garden can continue to provide bold colour until frost. Here are five hardy, long-flowering plants for August and September.
Summersweet (Clethra alnifolia, zones 3 to 9)
Summersweet is a small to medium sized shrub that is a late summer superstar! It flowers from August to mid-September with the unique bottlebrush-shaped flowers perfuming the garden with their sweet scent. Depending on the cultivar, the flowers may be creamy white or bubblegum pink and both are a favourite of bees, butterflies, and hummingbirds. Summersweet is native to eastern North America and grows about four to six feet tall, but if it’s very happy, it may reach heights up to eight feet. Plant it in partial shade to full sun. ‘Ruby Spice’ is a popular summersweet with intensely fragrant rose-pink flowers.
New England Asters (Symphyotrichum novae-angliae, zones 4 to 8)
There are so many reasons to plant New England asters in your garden. First, they bloom late and long, often flowering for six weeks or more. They’re also bee magnets with their daisy-like flowers providing nectar and pollen when many others perennials have faded. I also appreciate the bold and bright flower colours which include many shades of purple and pink. These perennials grow from two to four feet tall, depending on the species and are reliable, hardy, and pest and disease resistant. ‘Purple Dome’ is a show-stopping cultivar that grows two feet tall and has lavender-purple flowers with sunny yellow centers. ‘Alma Potschke’ is tall, reaching four feet in height and topped with magenta pink flowers.
Sedum spectabile (Hylotelephium spectabile, zones 3 to 9)
If you want to host a pollinator party in your late summer garden, plant sedum spectabile. The flat topped pink flower heads are VERY attractive to pollinators and beneficial insects and they bloom for over a month. This is also one of the easiest perennials to grow and offers interest from late spring through autumn. The succulent leaves and stems hold up well in drought and dry conditions, and there are several outstanding garden cultivars. ‘Autumn Joy’ is the best known and has large dusky pink flowers that mature to a deep red. There are also cultivars like ‘Purple Emperor’ with purple-burgundy leaves and stems. These add unexpected colour, especially when the pink flowers open.
Sneezeweed (Helenium autumnale, zones 3 to 8)
This is a great perennial with an unfortunate name. It won’t make you sneeze, but it will light up the late summer landscape and attract bees and butterflies. Depending on the cultivar, sneezeweed plants grow two to five feet tall and have yellow, orange, or red daisy-like flowers with brown centre cones. The showy plants are deer-resistant and tolerant of drought. Plant sneezeweed in full sun and deadhead flowers as they fade to prolong the bloom. ‘Ruby Tuesday’ is an excellent compact selection that grows just two feet tall and has deep red flowers. ‘Short and Sassy’ has orange and gold flowers with large chocolate cones and the plants are only 12 to 18 inches tall. Perfect even for small garden spaces.
Joe Pye weed (Eupatorium purpureum, zones 2 to 9)
Joe Pye weed may have ‘weed’ in its name, but it’s a fantastic garden plant that offers long-lasting height and colour to the August and September landscape. This North American native typically grows five to seven feet tall and looks great at the back of a border or along a fence. It thrives in full sun to partial shade and is also deer and rabbit resistant. And while many cultivars grow tall, ’Baby Joe’ is a short stature Joe Pye weed and only grows four feet tall.