Common Butterbur Makes Uncommonly Big Impact

But Be Careful!

Image: variegated common butterbur.
Variegated common butterbur is sure to capture attention with its two-toned, big leaves. David Beaulieu

What Is Common Butterbur?

The botanical name used in plant taxonomy for common butterbur is Petasites hybridus. The plant featured in the picture is a variegated type and thus bears the cultivar name 'Variegatus.' This is the kind I grow in my own landscaping.

Common butterbur is classified botanically as an herbaceous perennial. It is in the aster family. According to Botanical.com, the genus name, Petasites comes from the Greek, petasos (felt hat worn by shepherds), a reference to the fact that the leaves are so big they could function as hats, in a pinch.

 The common name, meanwhile, alludes to the practice (prior to the invention of refrigeration) of wrapping butter in the leaves to preserve it for longer. It thus solved a problem in the old days; nowadays, it is more likely to be considered problematic (see below).

What Does It Look Like?

This is a robust perennial, topping out at about 3 feet in height, and with a spread of up to 5 feet. Grown primarily as an outdoor foliage plant, the pinkish flowers, nonetheless, are not altogether lacking in interest, mainly because they are among the earliest spring flowers (blooming typically in April in zone 5). Furthermore, they're rather novel-looking -- which is fortunate, considering that they can hardly be called "beautiful." The actual flowers are tiny, but they are clustered atop a flower stalk that also sports greenish sepals.

As sweet a curiosity as the flowers are for die-hard plant geeks, though, the general gardening public will be focused almost exclusively on the leaves.

Not only are the heart-shaped leaves large (the biggest on mine are 13 inches across), but, on the variegated type (cream and green color combination), they are truly lovely.

Geographical Origin, Growing Conditions

Indigenous to Europe, the recommended planting zones for common butterbur in North America are 5-9.

Preferred growing conditions are shade and wet soil. Partial shade is OK (and may be better for the variegated cultivar to achieve optimal coloration in the leaves), as long as the plant receives sufficient water, but you can also treat it as one of the plants for full shade.

Given its huge leaves and cravings for wet soil, an alternate common name, not surprisingly, is "bog rhubarb."

Other Types

Petasites hybridus is perhaps less well-known than the Japanese types of butterbur (or fuki as it's known in Japan):

  1. Petasites japonicus: Japanese butterbur, the native, species plant
  2. P. japonicus ssp. giganteus: giant butterbur 
  3. P. japonicus 'Variegatus': variegated Japanese butterbur

Care for Common Butterbur and Why It Is Problematic

You may have to kill some slugs in caring for common butterbur plants (they eat holes in the leaves), but that will hardly be your biggest challenge. That honor goes, instead, to keeping them from spreading to areas of your landscaping where you do not want them to grow. For, propelled by vigorous rhizomes, they are very invasive plants whose natural tendency is to colonize and form monocultures. They will pop up even where you don't want them (if given the right growing conditions) unless carefully contained.

I grow mine in a pot; others erect bamboo barriers to restrain them.

When given too much sunlight, the leaves will wilt during the middle of the day in hot weather. Treat such an occurrence as a red flag indicating that you may have mislocated your common butterbur. There's no need to panic upon seeing this, though, fearing that the plants have died, as they will revive once the sun goes down. As the summer progresses, the oldest leaves will begin to die (sometimes their stalks are snapped in high winds, as well), but your foliage display will be replenished by the crops of new leaves that continually emerge. 

Related to the Wild Plant, Coltsfoot

Common butterbur is related to coltsfoot (Tussilago farfara). Not familiar with coltsfoot? You may well be familiar with what it looks like without actually ever having identified it and attached a name to it.

This ubiquitous wildflower is one of the first to bloom in spring in my region, New England (U.S.). Unless you've studied wild plants, you may well think of it as "some sort of dandelion" when you see it in flower. However, it blooms well before the dandelions; moreover, unlike with dandelions, the flower precedes the appearance of any foliage.

While the leaves of coltsfoot are tardy in appearing in spring, they make up for it later in the year, when they take center stage. The common name derives from the shape of this foliage. These leaves, by late summer, are large enough to attract notice from anyone who pays attention to wild plants when walking out in the woods. They caught mine years ago, before I knew they belonged to the coltsfoot plant (with which I was familiar only while in bloom). So many months elapse between the passing of the flower and the leaf's accumulation of heft that I had simply never made the connection (the plant is exceedingly unnoteworthy during the intermediate period). I was quite pleased with myself when I finally solved this plant-identification mystery. 

Incidentally, the close family ties between common butterbur and coltsfoot are revealed in two names:

  1. The common name, "sweet coltsfoot" is sometimes applied to common butterbur.
  2. And it was even listed as being in the same genus in the past, when it was known botanically as Tussilago petasites.

Other Plants With Huge Leaves

If you're fascinated by the size of the foliage of butterbur but would rather grow a different kind of plant, other options with huge leaves that are hardy to zone 5 include:

  1. Rhubarb
  2. Leopard plant 
  3. Mayapple
  4. Some types of hostas

Nor should Northerners hesitate to make use of tender plants during the summer to make a big splash in their yards; they're well worth the expense in most cases if your objective is to create a tropical feel in your landscape. Examples of large-leaved plants Northerners can treat as annuals include:

  1. Gunnera manicata (cold-hardy to zone7) 
  2. Elephant ears (cold-hardy to zone 8)

    Uses in Landscaping

    Clearly, such a dynamic plant will naturalize under the right conditions (which may be a good or bad quality, depending on your perspective). Common butterbur's shade-loving attribute makes it a natural for woodland gardens, while its preference for moist soils qualifies it for:

    1. Problematic wet areas
    2. Rain gardens
    3. Bog gardens
    4. Use around the perimeters of water features (most likely as a potted plant in small yards)

    Again, grow it in a container if you wish to keep it from spreading out of control.

    In terms of landscape design, it's easy to exploit this perennial's coarse plant texture to form interesting juxtapositions with other plants. Group it with plants tolerant of the same growing conditions that exhibit a finer texture, such as meadow rue, to create sharp textural contrasts. Variegated common butterbur makes a magnificent specimen plant for container gardens.