Colorful Charismatic Vines: Clematis in Bloom

Clematis season is upon us, with plants flowering in the early summer and throughout the season here in Pennsylvania. Clematis are often referred to as “queen of the flowering vines” with more than 350 different species of these perennial favorites found around the world. Clematis can be grown in zones 4 through 7 (sometimes warmer) and most of these plants are native to North America and to Asia. These perennials are known for their attractive flowers, which can be found in many different varieties, representing variable bloom periods, colors, and growth habits.

Most clematis need at least 6 hours of sunlight per day and ample moisture during the growing season to really thrive, although there are varieties available that can tolerate shadier environments. Clematis do well with a support structure because they have a rambling nature (unless you are planting a ground or bush clematis that doesn’t have a vining nature).

You can find more than 50 clematis specimens, composed of 18 different varieties, throughout the Arboretum, with peak bloom periods from late May to late August (although some species will continue blooming through October). While most herbaceous clematis flower during the summer months, climbing or vining clematis are divided into three groups depending on their flowering time: winter and spring–flowering, early summer–flowering, and late summer–flowering.

The early summer–flowering clematis (such as Clematis (Early Large-Flowered Group) ‘Nelly Moser’) pictured above, are also known as twice-flowering, since many varieties produce flowers in late spring or early summer and again in late summer. Their spectacular blooms vary in size and color, with large-flowered blooms reaching upwards of 10 inches in diameter.

There are three general flower forms, including loose clusters (such as Clematis virginiana), bell-shaped (such as Clematis ‘Duchess of Albany’), and flat or open flowers (such as Clematis ‘Mazowsze’), that range in color from white, blue and violet to purple, pink, and even bicolor.

Be on the lookout for more clematis blooming throughout the summer season. Late-summer flowering plants will start blooming in the coming months and will be visible around July (such as Clematis (Late Large-flowered Group) ‘Huldine’ pictured below).

Most varieties of clematis in the Arboretum are featured in the Rose and Fragrance Garden, however, those native to Pennsylvania (such as Clematis virginiana) can be found in the Pollinator and Bird Garden and in the Childhood’s Gate Children’s Garden. Be sure to stop in and witness these beautiful blooms throughout the summer and early autumn months!