Bog Garden Flowers

Astilbe

The astilbe flower is promoted by many garden centers for shade gardens. However, without an ample supply of moisture, these late spring through summer flowers will never reach their glorious potential. Astilbes are a slow-growing perennial, so unless you’re planting a large group, start with potted plants.

Depending on the variety, their height ranges from 6 inches to 5 feet. In spite of the astilbe’s need for abundant moisture (dry spells will induce dormancy), some drainage during the winter months is necessary. Astilbes are heavy feeders, so regular soil amendment and fertilizer is important.

Cardinal Flower

The cardinal flower is a native red flower that attracts hummingbirds to shady areas. The spikes of the flowers can reach 8 inches, and the plants can grow up to 6 feet tall, depending on the variety. Insect pests won’t bother your cardinal flowers, but browsing deer may consider it a snack.

The plant is vigorous without being invasive, and if you wish to propagate it, you can easily do so by layering. Layering is started by taking a branch that's still attached to the plant and gently bending the middle down to touch the earth, covering it with soil. Roots will sprout along the part of the stem that's underground, and it will eventually become a separate plant. 

Goat's Beard

Another fine native wildflower, the Aruncus dioicus, has blooms similar to the feathery astilbe, only on taller 6-foot plants. This summer bloomer will fill your shady bog garden with volunteer seedlings if you let it.

Not all goat's beard plants bloom equally—plants that produce male flowers (with many stamens per blossom) are showier than female plants.

Lady's Tresses

Although Spiranthes is rarely at nurseries, this delicate, native orchid is worth seeking out from responsible growers who cultivate the plants. Do not gather them in the wild as they are considered endangered. Unlike lady’s slippers and some other hardy native orchids, lady’s tresses are easy to grow, rewarding you with a jasmine-like fragrance for weeks in the fall.

Ligularia

Commonly called the leopard plant, this shade-loving bog flower is pleasing to the eye even when not in bloom due to its large, circular foliage. It's important to keep this plant well-irrigated during long spells of hot, dry weather. Otherwise, your plants may attract aphids. Try ‘Britt Marie Crawford’ for purple leaves in addition to golden flowers.

Mimulus

Whether or not you believe Mimulus plants deserve the moniker of monkey flower due to the blossom's resemblance to a monkey’s face, you'll find that this plant is easy to please in a rain garden or other wet site in your partially sunny landscape. Native forms sport lilac blooms, or you can choose from hybrid cultivars in a rainbow of solid and bicolors.

Monarda

Once upon a time, bee balm got a bad reputation for being a mildew-prone plant that gobbled up any free garden space it could. Now, gardeners choose from better behaved varieties like the purple ‘Scorpio’, red ‘Jacob Cline’, or pink ‘Marshall’s Delight’. While the mildew problem has been addressed, this member of the mint family will spread rapidly, so remove unwanted plants as needed.

Primrose

Candelabra primroses offer Easter egg colors from late spring into early summer, when most primroses are finished with their blooming cycle. Many flowers have a contrasting eye, and some have evergreen foliage.

Siberian Iris

The bearded iris has enjoyed the limelight in many gardens, but the smaller Siberian iris rarely succumbs to the iris borer or leaf spot disease that claims many bearded iris specimens. To add to its low-care appeal, Siberian irises rarely require division. Your plants may take a few years to get established, so don’t remove them if they don’t seem to take off at first.

Turtlehead

The white or pink flowers of the chelone make a welcome appearance in shady, wet areas during August and September. The plants prefer dappled shade to dense shade, which can cause weak stems that flop over. Turtleheads appreciate humus-rich mulch in addition to very moist soil.