Gardening: Some good choices for fall-blooming perennials

By the time September rolls around, I’m ready to put down my garden tools and put my feet up. But I’m not ready for Mother Nature to call it quits. While I’m lounging in my rocker, sipping a cold beer, I expect my garden to look grateful for all the hard work I’ve devoted to it. I want to see plants blooming and growing, still feeding the bees and butterflies until the snow hits. If you feel the same way, there are several perennials that will keep blooming into October and even November.

Of course, asters and chrysanthemums are wonderful fall bloomers, but did you know that many salvias and agastaches keep blooming past September? Other sun-loving plants that last through October include the following:

By Bridget Tisthammer
Colorado State University Extension Master Gardener in Larimer County

Fernleaf yarrow (Achillea filipendula, varieties ‘Coronation Gold’ and ‘Gold Plate’)
This tough plant hails from the Caucasus Mountains in Southeastern Europe. Medium green, ferny foliage and large, bright yellow umbels of flowers add punch to a low-water garden. Blooms in early summer and again in fall. Height: 2.5-4′, Width: 3′. Low water.

Lavender (Lavendula angustifolia, varieties ‘Hidcote’ and ‘Munstead’)
Known for its delicious fragrance, the silver foliage of lavender gives rise to spiky, purple blooms from early summer to fall. Height: 1-3′, Width: 1-3′. Low water.

Catmint (Nepeta species, most varieties)
The soft blue-silver foliage of catmint is similar to lavender, but the blooms are two-toned blue and purple. After a stunning first bloom in spring, shear it back for sporadic blooms all summer. Catmint will bloom profusely again in the fall. Catmint varieties can range from less than 12″ to 4′ in height and equally variable widths. Catmint reseeds freely and is a low water plant.

Mexican hat prairie coneflower (Ratibida columnifera, variety ‘Pulcherrima’)
Mexican hat is native to most of the lower 48 states. Its prolific red and yellow flowers resemble a Mexican sombrero, and the plant has an open, airy structure. This wildflower establishes easily and can be grown from seed. Height: 1-2′, Width: 1-2′. Low water.

Pincushion flower (Scabiosa causica, varieties ‘Perfecta Alba’ and ‘Blue Perfection’)
Another hardy flower from the Caucasus Mountains is the pincushion flower. Deeply divided leaves form a clump at the base of the plant, from which erect stems emerge bearing pincushion shaped flowers in lavender, white or blue. Scabiosa blooms from late summer into fall. The flowers of this plant are attractive to bees and other pollinating insects. Height: 2′, Width: 2′. Moderate water.

Hummingbird flower (Zauschneria californica latifolia)
This is a relative of the 2001 Plant Select winner, Zauschneria canum garrettii. Hardy to 10,000′, this low-growing plant sports bright green foliage and intense red, tubular flowers. Very attractive to hummingbirds. Height: 2′, Width: 3-4′. Low water.

Desert zinnia (Zinnia grandiflora)
This diminutive shrub from the southwestern U.S. reaches only 6-8″ high. Silver-blue needles form a compact mound, followed by a profusion of sunny yellow, 3-6 petaled flowers. Perfect for rock gardens or other dry areas. This plant spreads by rhizomes, so it can be used for erosion control on hot, dry slopes. Very attractive to bees and butterflies. Height: 6-8″, Width: 3-6″. Low water.

Perennials for sun to part shade that will keep blooming as the days cool include:

Dianthus hybrid (Dianthus, variety ‘First Love’)
This Plant Select choice for 2001 is reported to continue blooming into November. Medium green, upright stems support a long succession of highly fragrant flowers. First Love blooms emerge white, then slowly change to pale pink and finally to deep rose. Height: 18″, Width: 18″. Moderate water.

Obedient plant (Physostegia virginiana varieties ‘Pink Bouquet’ and ‘Summer Snow’)
This pretty Missouri native has bright green foliage and showy blooms that resemble snapdragons. Flowers are either pink or white, and may need to be staked if the soil is too fertile. Obedient plant can spread aggresively if conditions are right, so divide it every two to three years to keep it under control. Height: 3-4′, Width: 2-3′. Moderate water.

Corsican violet (Viola corsica)
This sweet little plant was recommended by Plant Select in 2003. The Corsican violet is a low-mounding perennial, with medium green leaves and cheerful flowers that continue from early spring well into fall. The face of the five-petaled flower is a soft purple with a yellow eye and tiny whisker markings. This plant withstands the cool temperatures of early spring and late fall, intense heat and poor soils. Height: 6-8″, Width: 6-8″. Moderate water.

Perennials for part to full shade that bloom into October include the following:

Japanese anemone (Anemone x hybrid, varieties ‘Whirlwind’ and ‘Prince Heinrich’)
The Japanese anemone sports dark green, trifoliate leaves that form a mound, from which graceful stems arise carrying blooms of white or pink. This is a fall anemone with a long bloom time from September through October. Will naturalize in the right setting. Height: 2-3′, Width: 2-2.5′. Moderate water.

Black snakeroot (Actaea simplex, variety ‘Atropurpurea’)
Native to the Ozarks region, black snakeroot is noted for its lacy, bronze foliage and highly fragrant racemes of white blooms that resemble fluffy tails. Height: 3-4′, Width: 2-3′. Moderate water.

Before you put away your tools, add a few of these late bloomers to your garden and sit back to enjoy the show. For more information about perennials for Colorado, visit the Colorado State University Extension website at www.ext.colostate.edu and select Fact Sheet #7.405, “Herbaceous Perennials” and also visit the Plant Select website at www.plantselect.org.