Choosing Summer-blooming perennials to brighten up your garden

Herbaceous perennials, plants that return year after year, but lack the woody stems of trees and shrubs, are some of my favorite ornamental plants in the summer garden. Unlike their early season counterparts, summer-blooming herbaceous perennials tend to have a long ornamental season.  Many flower for several weeks, providing consistent color as well as pollen and nectar for beneficial insects like bees and butterflies. They can also provide interesting foliage and structure in the summer garden.

When choosing plants for your garden, it’s important to consider not only bloom time and flower color, but also a plant’s cultural requirements. Do you have full sun (at least 6 hours of direct sunlight per day)? Are your garden soils moist and rich with organic matter or dry and sandy?  Once you understand the cultural conditions your garden provides, you can start to make plant choices based on your particular aesthetic or ecological preferences. The following short list of stand-out summer-blooming perennials includes descriptions of each plant’s ornamental characteristics and cultural requirements, as well as a note or two about ecological characteristics, like whether they are host plants for beneficial insects like pollinators.

Cardinal flower (Lobelia cardinalis)Cardinal flower is a mid-summer flowering perennial with brilliant red flowers. It grows naturally in wet areas, along streams and rivers and in sunny marshes. In the garden, it will grow best in soils with plenty of moisture and in full sun. The flower is distinct for its brightness, attracting hummingbirds and many species of butterflies. Horticulturists have hybridized red and blue cardinal flower, resulting in many cultivars of flowering plants that exhibit characteristics of either species. Unfortunately, research conducted by Annie White, PhD. demonstrated that hybrids can have diminished nectar quality, potentially making them less supportive of hummingbirds than the natural species. For this reason, when planting cardinal flower to support hummingbirds, avoid cultivars.

More Central Mass. Gadening: Balancing act: The nostalgia of cut grass, the benefits of low-impact lawn maintenance

More Central Mass. Gardening: Front porch gardening: the art and science of gardening with limited space

Purple Joe-Pye weed (Eutrochium purpureum)Purple Joe-Pye weed is a towering perennial in the aster family with large clusters of late-summer pink-purple flowers atop stems that can reach 6-feet tall. Like cardinal flower, it naturally grows in wetland margins, but can tolerate a range of soil moisture and soil types. Purple Joe-Pye weed is a great addition to a perennial border for its long-lasting floral display in late summer. Its fragrant flowers attract dozens of butterfly and bee species.

Rozanne geranium (Geranium ‘Gerwat’)Rozanne geranium is a fantastic groundcover with a sprawling habit and almost iridescent violet-blue flowers that last throughout the summer. There are many different species of geranium, including a New England native wildflower called spotted cranesbill (Geranium maculatum). In contrast with the common annual “geranium” (which are actually not geraniums at all but are in a related plant genus called Pelargonium), Rozanne geranium and spotted cranesbill are perennial, returning year after year following a winter dormancy period.

Rose milkweed (Asclepias incarnata)Common milkweed (Asclepias syriaca) rightfully earns its reputation as a weed in all but the wildest gardens. It is highly adaptable, easily spread by seed, and difficult to remove once established. Like all milkweeds, however, it is the only food source for monarch caterpillars. Fortunately, there are a number of other milkweed species better suited for use in traditional gardens. In the wild, rose milkweed is found in wet soils, from lake shores to wet meadows. It is considered an obligate wetland species, meaning its presence indicates an area is in fact a wetland. Despite its natural habitat, it does quite well in average garden soils with good moisture. It features beautiful pink to light-purple flowers that are quite fragrant.

Broad-leaved mountain mint (Pycnanthemum muticum)Broad-leaved mountain mint is one of six mountain mint species found in New England. As a member of the mint family, it features leaves and stems that give off a minty fragrance when touched. It is also a pollinator magnet and an important nectar source for native insect species in mid- to late-summer. Flowers are white with spots of color, borne in clusters atop tall stems about two feet in height. Just below the flowers is a silvery bract that has a light, dusted appearance and a bright pop at the top of a stem covered in light green leaves.

Gardening Central Mass. is written by New England Botanic Garden at Tower Hill CEO Grace Elton and other Garden experts. Located on 200 acres in Boylston, New England Botanic Garden creates experiences with plants that inspire people and improve the world. Learn more at www.nebg.org. The column is published on the third Sunday of the month.

This article originally appeared on Telegram & Gazette: Gardening Central Mass.: Summer-blooming perennials you'll love