When Do Perennials Flower?

March Bloomers

• The perennials generating flowers in March include many types of a plant called hellebore. One type, stinking hellebore, gets its name from the unusual smell of its flowers, which are greenish-white and sometimes bloom by February from USDA plant hardiness zones 5 through 9. Hellebore hybrids for March flowers include Blue Lady, Pink Lady, White Lady and Red Lady, with the color of their flowers indicated by their name. Dutchman's breeches is a March bloomer, with its white flowers resembling tiny pair of pants hung out to dry upside down by some woodland fairy. The species works in native gardens and woodland gardens. Virginia bluebells, hepatica, false rue anemone and bloodroot also flower as perennials in March.

May Bloomers

• Loads of perennials kick things into high gear by May, including many sorts of columbines, windflowers, astilbes and bugleweeds. Species of indigo like false indigo and yellow false indigo flower during May, as do some tickseeds, bleeding hearts, sweet Williams and cranesbills. Siberian iris hybrids such as Ego, Chilled Wine and Clarence flower in May. The delicate forget-me-not blooms during May, with the small perennial an option as ground cover, wildflower meadows, flower borders and for planting on hillsides, reports Perennial Resource.

August Bloomers

• August is a month where many perennials end their bloom period, but some are just beginning to flower. The pinkish-purple flowers of the New England asters are among the latter, with the plant growing to 6 feet and suitable for cottage and butterfly gardens. Perennials for water gardens and pond borders such as pickerelweed and the Victorian water lily bloom for August. Toad lily, speedwell, ironweed, sage and stonecrop flower in the eighth month. Goldenrod cultivars including Crown of Rays and Goldrush work well as container plants or in naturalized areas, providing a yellow presence during August.

October Bloomers

• Chrysanthemum cultivars such as Bravo, Brandii and Grenadine are available at greenhouses and nurseries for those wanting October perennial flowers. Many kinds of stonecrops, sneezeweeds, black-eyed Susans and pincushion flowers offer October blooms. Aromatic aster, heath aster, calico aster and smooth aster all flower during autumn's first full month. Growing to 30 inches tall, the late purple aster ends its flowering in October, attracting the last of the season's butterflies.