Sunday, July 1, 2012

Great Laurel - Rhododendron maximum

It was a treat to be in the mountains this past week during the peak bloom time for great laurel, Rhododendron maximum. Usually I visit the mountains in the spring for wildflower viewing or during the fall for foliage, so being here in late June is different. The June flowering plants are a modest group compared to the spring show, but the great laurel is amazing this time of year and it is putting on a great show.

Great laurel, Rhododendron maximum

Our summer vacation this year was in Gatlinburg, TN which is on the edge of the Smoky Mountains. From the moment we drove into Great Smoky Mountains National Park from Cherokee, NC it was apparent that we were in for a treat. Rhododendron maximum is a dominant part of the plant community in much of the park, particularly along the drive through. Any other time of year it is a thick tangle of undergrowth, a tall gangly shrub with long, leathery leaves that droop and curl during freezing weather. Come June and July, these shrubs light up the forest with millions of large white bell-shaped flowers held in clusters on branch tips and scattered on the forest floor when they drop. Now that they are blooming, one realizes just HOW prevalent this plant is!

The blooms of Rhododendron maximum really light up the forest

Great laurel is native to much of the eastern part of the US; the range spans from Georgia to Maine and it is most common in the mountainous parts of that range where it can grow up to 40 feet tall. It does produce seed in capsules, but much of it's growth occurs through root sprouting. It tends to create large colonies where it grows, outcompeting other plants and creating a closed canopy with very little undergrowth - including its own seedlings! In many areas I saw thick carpets of low growing groundcovers like Galax urceolata and partridgeberry (Mitchella repens) on the sunny edges of the thickets. A taller herbaceous layer of ferns, Solomon's plume (Maianthemum racemosum) and violets (Viola spp.) was evident as well.

Pink form of Rhododendron maximum

While blooms are usually white, the buds before they open are pinkish and occasionally we would find open blooms that retained a pink blush. That is the nature of nature, of course, that color forms may vary and even some reddish forms have been found and used to create cultivars.

Of note: According to the website,, "The confusing names 'Maximum Roseum' and 'Maximum Album' are both most likely R. ponticum hybrids that probably do not contain any R. maximum."

Rhododendron catawbiense

This is not the only evergreen Rhododendron in the park, and I was fortunate to find a few last blooms of Rhododendron catawbiense at high elevations (around 5000 feet) near the top of the Alum Cave Bluff trail. This shrub is normally found at higher elevations and is at peak bloom time earlier than the great laurel.


  1. Ellen, In the 1970s, I lived in southeastern Connecticut, and a hiking trail called the Pequot Trail passed near our house. I used to love to hike one part of the trail in early summer because it had huge towering rhododendrons that were breathtaking; I was always trying to time the hike to do it when these plants were in bloom. I'm guessing that these were Rhododendron msximum. -Jean

  2. What beautiful plants, I've always longed to have rhododendrons in my yard, someday I hope to live somewhere moist enough to be able to grow them.