Tuesday, April 27, 2021

Episode 574 (4-26-21): Rhododendrons Span Virginia from Ridges to Swamps

Click to listen to episode (4:36)

Sections below are the following:

Transcript of Audio
Audio Notes and Acknowledgments
Extra Information
Related Water Radio Episodes
For Virginia Teachers (Relevant SOLs, etc.)

Unless otherwise noted, all Web addresses mentioned were functional as of 4-23-21.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of April 26, 2021.  This revised episode from June 2014 is part of a series this year of spring-related episodes.

MUSIC – ~17 sec – Lyrics: “I can’t explain away the reasons, I can’t wish away the seasons.  When springtime comes again, it’ll sure by my winter’s end.”

This week, that music opens an episode about a group of plants with species found across Virginia and whose blooming times collectively span a period from early spring well into summer.  Have a listen for about 50 more seconds to the song and its celebration of some members of this plant group found high up in southwestern Virginia.

MUSIC – ~48 sec – Lyrics: “Well I was high up in the fields, there above the rhododendron ridge.  My time up there was real, not like some other time I’ve spent.  And when the flowers bloom in June, it’s like something you’ve never seen—shades of purple, white, and blue, as far as you can see.” 

You’ve been listening to part of “Rhododendron Ridge,” by the Roanoke, Va., band The Floorboards, on their 2012 self-titled album.  The song was written about the area around Mt. Rogers—Virginia’s highest peak, located in Grayson and Smyth counties.  Mt. Rogers is noted for its populations of Catawba Rhododendron and its flower displays in June.  Catawba is one of Virginia’s nine native species in the scientific genus of Rhododendron, some of which are commonly called azaleas.  As a group, their habitats range from rocky mountainous areas, to Piedmont streams, to Coastal Plains wetlands.  Their blooming times range from March to August, depending on the species. These perennial spring and summer flower shows happen in places where the plants’ roots and leaves get their preferred combination of sun or shade, temperature, moisture, nutrients, and acidity levels in the soil and soil water.  Virginia’s rhododendron species typically prefer higher acidity, and they share that preference with other members of the heath family of plants, including blueberries and Mountain Laurel.

While you can’t see the water chemistry going on around rhododendron roots, at the right time and place you can see a remarkable flower display, which might be for you—as for this week’s songwriter—like something you’ve never seen. 

Thanks to the Floorboards for permission to use this week’s music, and close with about 25 more seconds of “Rhododendron Ridge.”

MUSIC – ~28 sec – Lyrics: “Springtime’s comin’ now, oh it won’t be long—you and I we’re gonna sing, gonna sing our summer song.”


Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  For more Virginia water sounds, music, or information, visit us online at virginiawaterradio.org, or call the Water Center at (540) 231-5624.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close this show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


This Virginia Water Radio episode replaces Episode 216, 6-2-14.

“Rhododendron Ridge” is copyright 2012 by The Floorboards, used with permission.  More information about The Floorboards is available online at https://thefloorboardsmusic.com/.

Thanks to the following people for providing information in 2014 for the original version of this episode: Susan Day, John Peterson, and John Seiler, all in the Virginia Tech Department of Forest Resources and Environmental Conservation; and the staff and volunteers working at the Blue Ridge Parkway’s Rocky Knob Visitor Center (mile post 169) on June 1, 2014.

Click here if you’d like to hear the full version (1 min./11 sec.) of the “Cripple Creek” arrangement/performance by Stewart Scales that opens and closes this episode.  More information about Mr. Scales and the group New Standard, with which Mr. Scales plays, is available online at http://newstandardbluegrass.com.


Great Rhododendron (Rhododendron maximum, right), Flame Azalea (Rhododendron calendulaceum), orange flowers, left) and Mountain Laurel (Kalmia latifolia, foreground) along the Blue Ridge Parkway in Floyd County, Va., June 1, 2014.

Side-by-side Flame Azaleas (Rhododendron calendulaceum) showing color variation, along the Blue Ridge Parkway in Floyd County, Va., June 1, 2014.

Swamp Azalea (Rhododendron viscosum), photographed at Sandy Bottom Nature Park in Hampton, Va., June 14, 2009.  Photo by Debbie Blanton, made available on iNaturalist, online at https://www.inaturalist.org/observations/35506117 (as of 4-26-21), for use under Creative Commons license “Attribution-NonCommercial 4.0.”  Information about this Creative Commons license is available online at https://creativecommons.org/licenses/by-nc/4.0/.


The following information about nine native species of Rhododendron found in Virginia is from pages 540-543 in A.S. Weakley, J.C. Ludwig, and J.F. Townsend, Flora of Virginia, Bland Crowder, ed.; copyright by the Foundation of the Flora of Virginia Project, Inc., Richmond; published by Botanical Research Institute of Texas, Fort Worth, 2012.  The species are listed in alphabetical order according to their scientific name (shown in italics).

Sweet Azalea (also called Smooth Azalea), Rhododendron arborescens – Found rarely in Virginia’s mountains and Piedmont; in rocky forests and rocky areas along streams; blooms May to July.

Dwarf Azalea, Rhododendron atlanticum – Found commonly in Virginia’s southern Coastal Plain; in woodlands and clearings that are dry to moist, sandy, and acidic; blooms April to May.

Flame Azalea, Rhododendron calendulaceum – Found commonly in Virginia’s southern mountains; in forests that are dry to mesic (moderately moist), particularly in acidic oak forests; blooms May to June.

Catawba Rhododendron (also called Pink Laurel and Mountain Rosebay), Rhododendron catawbiense – Found commonly in Virginia’s southern and rarely in the Piedmont; in dry forests on sheltered slopes or rocky ridges, as well as on balds, in bogs, and in acidic cove forests, and (in the Piedmont) along river bluffs; blooms April to June.

Cumberland Azalea, Rhododendron cumberlandense – Found infrequently in Virginia’s far southwestern mountains; in mountainous forests and woodlands; blooms June to July.

Great Rhododendron (also called Great Laurel and White Rosebay), Rhododendron maxiumum – Found commonly is Virginia’s southwestern mountains and Piedmont, less frequently in northern mountains, and rarely in other parts of the Piedmont or in the Coastal Plain; in acidic cove forests in the mountains, and in forests, wetlands, bluffs, and stream bottoms in other regions; blooms June to August.

Wild Azalea (also called Pinxterflower and Pinxterbloom Azalea), Rhododendron periclymenoides – Found commonly throughout Virginia; in dry or mesic acidic forests, in certain wetlands, and along streams; blooms March to May.

Early Azalea (also called Rose Azalea and Roseshell Azalea), Rhododendron prinophyllum – Found frequently or commonly in Virginia’s mountains, except in far southwestern Virginia, and rarely in the northern Piedmont; in dry or mesic forests, most abundantly in oak forests, and more often in less acidic soils than are other Rhododendron species; blooms May to June.

Swamp Azalea (also called Clammy Azalea), Rhododendron viscosum – Found frequently in Virginia’s Coastal Plain, infrequently in the mountains, and rarely in the Piedmont; in acidic swamps, bogs, and other wetlands, and in wet woods; blooms May to July.


Used for Audio 

Blue Ridge Parkway Association, “Craggy Gardens, MP 364,” online at http://www.blueridgeparkway.org/v.php?pg=112.

Oscar W. Gupton and Fred C. Swope, Trees and Shrubs of Virginia, University of Virginia Press, Charlottesville, 1981.

W. Henry McNab, Ecological Subregions of the United States, U.S. Forest Service, Washington, D.C., 1994; available online at http://www.fs.fed.us/land/pubs/ecoregions/ch18.html.  See particularly Chapter 18, “Central Appalachian Broadleaf Forest - Coniferous Forest – Meadow.”

U.S. Forest Service, “Mt. Rogers National Recreation Area,” online at http://www.fs.usda.gov/detail/gwj/specialplaces/?cid=stelprdb5302337.

U.S. National Park Service, “Blue Ridge Parkway/Plants/Blooming Shrubs,” online at https://www.nps.gov/blri/learn/nature/showy-blooms.htm.

Virginia Botanical Associates, “Digital Atlas of the Virginia Flora/Rhododendron,” online at http://www.vaplantatlas.org/index.php?s=rhododendron&c=&do=search%3Aadvanced&search=Search.

Virginia Tech Department of Forest Resources and Conservation, “Virginia Tech Dendrology,” online at http://dendro.cnre.vt.edu/dendrology/index.html.

A.S. Weakley, J.C. Ludwig, and J.F. Townsend, Flora of Virginia, Bland Crowder, ed.  Copyright by the Foundation of the Flora of Virginia Project, Inc., Richmond.  Botanical Research Institute of Texas, Fort Worth, 2012.  This is the first comprehensive manual of Virginia plants published since the 1700s.  The Flora of Virginia Project is nline at http://www.floraofvirginia.org/.

For More Information about Plants in Virginia and Elsewhere

Chesapeake Bay Program, “Field Guide: Plants and Trees,” online at https://www.chesapeakebay.net/discover/field-guide/all/plants_trees/all.

Oscar W. Gupton and Fred C. Swope, series of wildflower guides: Fall Wildflowers of the Blue Ridge and Great Smoky Mountains, University Press of Virginia, Charlottesville, 1987; Wild Orchids of the Middle Atlantic States University of Tennessee Press, Knoxville, 1986); Wildflowers of Tidewater Virginia (University Press of Virginia, Charlottesville, 1982; and Wildflowers of the Shenandoah Valley and Blue Ridge Mountains, University Press of Virginia, Charlottesville, 1979.

U.S. Department of Agriculture (USDA)/Natural Resources Conservation Service Plants Database, online at https://plants.usda.gov.

Virginia Department of Conservation and Recreation/Natural Heritage Division, online at https://www.dcr.virginia.gov/natural-heritage/.

Virginia Native Plant Society, online at http://vnps.org/. 


All Water Radio episodes are listed by category at the Index link above (http://www.virginiawaterradio.org/p/index.html).  See particularly the “Plants” subject category.

Following are links to other spring-themed episodes. 

Eastern Phoebe – Episode 416, 4-16-18.
Frog and Toad Medley – Episode 408, 2-19-18.
Spring arrival episode – Episode 569, 3-22-21.
Spring forest wildflowers – Episode 573, 4-19-21.
Spring Peepers – Episode 570, 3-29-21.
Spring reminder about tornado awareness – Episode 568, 3-15-21.
Spring signals for fish – Episode 571, 4-5-21.
Spring sounds serenades – Episode 206, 3-14-14 and Episode 516, 3-16-20.
Virginia Bluebells – Episode 521, 4-20-20.
Warblers and spring bird migration – Episode 572, 4-12-21.


Following are some Virginia Standards of Learning (SOLs) that may be supported by this episode’s audio/transcript, sources, or other information included in this post.

2020 Music SOLs

SOLs at various grade levels that call for “examining the relationship of music to the other fine arts and other fields of knowledge.” 

2018 Science SOLs

Grades K-4: Living Systems and Processes
1.4 – Plants have basic life needs (including water) and functional parts that allow them to survive; including that plants can be classified based on a variety of characteristics.
2.4 – Plants and animals undergo a series of orderly changes as they grow and develop.
2.5 – Living things are part of a system.
3.4 – Adaptations allow organisms to satisfy life needs and respond to the environment.
3.5 – Aquatic and terrestrial ecosystems support a diversity of organisms.
4.2 – Plants and animals have structures that distinguish them from one another and play vital roles in their ability to survive.
4.3 – Organisms, including humans, interact with one another and with the nonliving components in the ecosystem.

Grades K-5: Earth and Space Systems
1.7 – There are weather and seasonal changes.
2.7 – Weather patterns and seasonal changes affect plants, animals, and their surroundings.
3.6 – Soil is important in ecosystems.

Grades K-5: Earth Resources
2.8 – Plants are important natural resources.
3.8 – Natural events and humans influence ecosystems.
4.8. – Virginia has important natural resources.  

Grade 6
6.6 – Water has unique physical properties and has a role in the natural and human-made environment.

Life Science
LS.3 – There are levels of structural organization in living things.
LS.5 – Biotic and abiotic factors affect an ecosystem.

BIO.2 – Chemical and biochemical processes are essential for life.
BIO.6 – Modern classification systems can be used as organizational tools for scientists in the study of organisms.
BIO.8 – Dynamic equilibria exist within populations, communities, and ecosystems.

Following are links to Water Radio episodes (various topics) designed especially for certain K-12 grade levels.
Episode 250, 1-26-15
– on boiling, for kindergarten through 3rd grade.
Episode 255, 3-2-15
– on density, for 5th and 6th grade.
Episode 282, 9-21-15
– on living vs. non-living, for kindergarten.
Episode 309, 3-28-16
– on temperature regulation in animals, for kindergarten through 12th grade.
Episode 333, 9-12-16
– on dissolved gases, especially dissolved oxygen in aquatic habitats, for 5th grade.
Episode 403, 1-15-18
– on freezing and ice, for kindergarten through 3rd grade.
Episode 404, 1-22-18
– on ice on ponds and lakes, for 4th through 8th grade.
Episode 406, 2-5-18
– on ice on rivers, for middle school.
Episode 407, 2-12-18
– on snow chemistry and physics, for high school.
Episode 483, 7-29-19
– on buoyancy and drag, for middle school and high school.
Episode 524, 5-11-20
– on sounds by water-related animals, for elementary school through high school.
Episode 531, 6-29-20
– on various ways that animals get water, for 3rd and 4th grade.
Episode 539, 8-24-20 – on basic numbers and facts about Virginia’s water resources, for 4th and 6th grade.