By Julie Boudreau
Don’t rush to cut back your perennial plant beds. Like trees and shrubs, certain perennial plants offer very beautiful foliage colors in the fall. It would be a shame not to take advantage of it!
As with all plants that change color in the fall, the coloring of perennials is influenced by reduced light and cool temperatures. In truth, fall colors are already found in the foliage during the summer. It is the abundance of the pigment chlorophyll that hides them. When chlorophyll dies, colors are revealed and, in some cases, intensified. If it is cool at night and warm during the day and if the sun is out, the colors will be more vivid.
Let’s discover some perennials less known to gardeners which deserve our full attention. And not just for the fall coloring of their foliage.
Barrenworts: Fairies of the Woods
Barrenwort (Epimedium spp.) is also called bishop’s hat (or elf flower in french). This superb slow-growing ground cover is a fabulous plant for beautiful beds in the shade. It also grows in partial shade or in inhospitable soils. In fact, the only place you can’t plant barrenwort is in full sun, because the foliage will burn under these conditions. In general, the foliage of barrenwort is green in summer, with tones of khaki or brown, depending on the variety. But in the fall, the foliage turns red or light orange.
The Epimedium is hardy up to zone 4a (USDA 5 to 9) and it blooms in spring. Typically, plants are around 1 foot (30 cm) tall. The foliage is semi-evergreen, which means it survives the winter. The old leaves disappear in the spring as soon as the new leaves appear. The plant is not subject to any major insect infestation. It makes an excellent border plant and although it grows slowly, it forms very beautiful clumps with little care.
Amsonia: The Blue Star That Turns to Gold
It is undoubtedly one of the most beautiful autumn colors that a perennial plant can offer us. In summer, Amsonia, or Blue Star (Amsonia spp.), is a very discreet perennial, with its small starry blue flowers. But in the fall, the foliage takes on shades of golden yellow and orange that dazzle the eye. The narrow-leaved species, Amsonia hubrichtii, is particularly spectacular.
Blue Stars grow in partial shade and full sun. They require very fertile soil to proliferate. If the conditions are good, they will stay in place for many years. Ignored by insects and diseases, the plant is hardy to zone 4 (USDA 4 to 9). There are now varieties as high as 1 foot (30 cm) tall, but in general amsonias are plants around 2 feet (60 cm) tall, sometimes more. These beautiful bushy plants go well with several perennials in the garden, but also rose bushes and shrubs with colorful foliage.
Mukdenia …the What?
Not the easiest name to pronounce and yet Ross’s mukdenia (Mukdenia rossii) is a beautiful plant to discover. It is a shade plant, having beautiful shiny foliage which reaches around 1 foot and a half (45 cm) in height. It is a covering plant which multiplies by rhizomes. This means that it will have to be monitored and controlled if necessary, but it is far from qualifying as an invasive plant. Its foliage sometimes takes on light red hues in summer, but in the fall it’s an explosion. A beautiful bright red!
The white bloom stands above the foliage in spring. The ideal soil for this plant is cool and slightly moist throughout the summer, but it can be grown in slightly drier soils, especially in the shade. Not much cultivated, we know that it is hardy in USDA zone 5 to 8. It remains to be seen whether it survives further north.
Rodgersia : The One Who Thinks It Is a Chestnut Tree
Rodgersia (Rodgersia spp ) is a shade plant best known for its palmate compound leaves which closely resemble chestnut leaves. Moreover, the Rodgersia species aesculifolia — aesculifolia meaning a chestnut leaf — is the most present on the market. There are several other species that are just as interesting. These large leaves take on shades of red and bronze that are difficult to describe in words, but the result is there! Beautiful fall coloring.
The rodgersia is a large plant, approximately 2 to 3 feet (60 to 75 cm) high, which forms a large clump. In summer, a beautiful white or pink flower stalk rises well above the leaves. It looks like a giant astilbe bloom. These perennials survive well up to zone 4 (USDA 5–8). They are a must-have addition to understory gardens and shade beds.
Bloody Cranesbill Reveals the Origin of Its Name
Bloody Cranesbill (Geranium sanguineum) is well known to gardeners. The purple-flowered species or the white-flowered cultivar (G. sanguineum ‘Album’) are widely grown. More rarely, we are interested in the dwarf variety ‘Max Frei’ with also purple flowers. Either way, this geranium’s finely lobed leaves turn bright red in fall. As red as a winged spindle!
This geranium is a full sun plant that tolerates some light shade. Bloody Cranesbill likes rich, well-drained soils, but it adapts quite well to less perfect soils. The plants measure between 9 inches (20 cm) and over 2 feet (60 cm) high, depending on the variety. Flowering is summer and very generous. In some gardens, the plant manages to reseed itself, which can be a small inconvenience. It is a very hardy plant, up to zone 4 (USDA 3 to 9) and even zone 3 (USDA 2). This geranium fits everywhere: in beds of mixed perennials, along the edges of paths. For the low-maintenance garden, this is a must-have.
Colorful fall foliage is not limited to these few perennial plants. Peonies, hostas, heucheras and tiarellas are also among them, along with several other plants. We must not forget to mention ornamental grasses in the passing. Their beautiful foliage allows us to enjoy the splendors of our gardens for a few more weeks… before the first snowflakes arrive.