JARS v51n2 - More Rhododendrons on the Move

More Rhododendrons on the Move
George Ring
Bent Mountain, Virginia

Throughout history, people have not been content to move to a new land without taking their favorite plants with them. Immigrants to the United States brought fruit trees and flowers from Europe to eastern America, and, in time, these or their progeny were moved westward with the pioneers. Rhododendrons and azaleas continue in this tradition of plants being moved to new locations. Many rhododendrons have been moved from private gardens to arboretums. A good example of this is the collection of rhododendrons at the Rhododendron Species Foundation, many of which survived four or more moves by the time they reached their present location at the Weyerhaeuser headquarters in Federal Way, Wash. Another example is the great collection of rhododendrons at Windsor Great Park in England, many of which were moved from the private collections of people who had subscribed to plant hunting expeditions and grown seedlings of species seed collected in the wild. In yet another example of moving rhododendrons, a commercial grower moves small plants from North Carolina to Florida in the fall to lengthen the growing season and then, in the spring, moves the larger plants back to North Carolina to finish them off for sale. On occasion large rhododendrons are moved long distances when members of the ARS move from urban areas to rural locations. One of the longest of these moves was by Russ and Velma Haag who moved over 6,000 rhododendrons from New Jersey to Brevard, N.C., in the 1970s.
This article is about another move of this type, during which some 3,000 rhododendrons and azaleas were moved 250 miles from Fairfax, Va., to Bent Mountain, Va., which is about 20 miles south of Roanoke. Some time and labor saving techniques are reported which proved successful and therefore might be of interest to other members who plan to move their rhododendrons in the future.
Shortly before retiring from work in the Washington, D.C., area in 1990, we began thinking of moving to a less crowded area somewhere in the eastern or southeastern United States. Accordingly, on a number of trips we looked at potential sites where rhododendrons could be grown and land was reasonably priced. The areas searched ranged from the Washington, D.C., area to as far south as the mountains of North Carolina. One of our trips we found a 55-acre tract available on Bent Mountain near Roanoke, Va., and decided that this was a prime candidate.
The land is mostly wooded with oaks, poplars, hemlocks and pines except for a 6-acre clearing in a meadow at the highest elevation (3,000 feet). The soil is acid, fairly well drained, and there are several springs and a small stream. A view toward the southwest extends 31 miles to Buffalo Mountain on a clear day - and about 60 miles to Comer's Rock on the very clearest days (about four or five a year). Native vegetation includes large specimens of Rhododendron maximum (to 15 feet) growing in the woods, as well as mountain laurel ( Kalmia latifolia ) and R. calendulaceum and R. periclymenoides (formerly R. nudiflorum ). The temperature averages 6°F to 8°F cooler than in Roanoke.
Arrangements were made to buy the property in 1990, and a used Ford F-250 pickup truck was obtained to haul the rhododendrons and azaleas. We planned to do most of the work ourselves, and so we looked for time-saving and easy shortcuts. Since balling and burlapping plants is laborious and time-consuming and usually requires intermittent watering, we decided to avoid this procedure by using a different method. A local nurseryman in Fairfax let us select a truckload of large plastic containers (mostly 17 inches in diameter and 15 inches tall - a few were larger and some were smaller) from his "bonepile." These were used over and over. The procedure was to put a thin layer (about 2 inches) of wet sphagnum peat in the bottom of the container to support the root mass and to help keep the roots moist. Wood chips were placed on top of the root mass and the plants watered and placed in a shady location until enough plants to fill the truck had been dug. Eventually, the plants were loaded into the pickup truck and a small trailer, usually two or more layers deep. Fifty to 60 fairly large rhododendrons could be hauled in one load when the plants were cut back to fit into the truck. The largest plants hauled were about 8 feet tall before cutting back. Up to 150 or more small plants (2 to 3 feet) could be hauled in a single load. About 3,000 dug plants were moved in all, plus about 750 in flats and 6-quart containers.
After driving the loaded plants 250 miles to their new home in the morning, they were unloaded and planting started in the afternoon. The planting sites selected were mostly in the meadow at the edges of the woods for some wind protection and were well away from the area where we planned to build a house. The most used tool was a heavy pick mattock for breaking sod in the meadow or for digging a hole in rocky soil in the woods where some of the rhododendrons were planted. Holes were no more than 6 inches deep and little larger in diameter than the root system. After thinly spreading the peat that had cradled the plant in the container, the plants were set and back-filled around the roots with soil dug from the hole. The plants were then thickly mulched with layers of wet newspapers, held down with wood chips from the top of the moving container and with rocks dug from the hole. Planting of a truck-load was usually completed by noon of the second day, followed by a 250-mile return to Fairfax by a tired man. Then the process was repeated for another load. The first trip was made Dec. 2 and 3, 1990. Eight more trips were made by May 28, 1991. After a pause for summer, 12 more trips were made by the middle of January 1992. The final 11 trips were made between July 2 and Sept. 24,1992. In all, 32 trips were made in a little less than two years.
We estimate that 2,000 or more rhododendrons were left in Fairfax, most being too big for us to move, and others were left because we ran out of energy. Intentional layers of three large special plants were moved, and later scions of about 50 others were rooted for us by Ed Reiley and have been transferred to Bent Mountain.
The rhododendrons and azaleas moved to Bent Mountain by the container method received no watering or other care for over two years. Somewhat surprisingly, nearly all of them have survived. We think this good survival rate is due to a number of factors, including the severe cutting back of the larger plants and making sure that the root masses were wet during the move. The heavy mulch of newspapers seemed especially beneficial by acting as a sponge, soaking up rainfall and then gradually releasing it to the plant during dry periods. It should also be noted that moisture movement in a vapor form from surrounding warm soil areas to the shaded cooler area under the mulch probably helped to maintain adequate moisture for the plants. One other factor contributing to the success might be the cooler temperature at the higher elevation, often dropping below the dew point at night and watering the foliage. The cooler temperature also results in less transpiration from the plant. Whether one of the factors was dominate or whether they acted in concert, we were happy with the results.
Possibly as a result of the moving stress on the plants, or maybe the increased exposure, or even the better drained soil, most of the evergreen azaleas and lepidote rhododendrons tended to cease top growth and regenerate with strong new growth from their bases after two or three years.
Our house was eventually completed and we have been living on Bent Mountain since Dec. 22,1993. That first winter was reported to be the worst for ice storms in the area in more than 30 years, and a low temperature of -13°F was recorded. However, we survived (with the help of a wood-burning fireplace insert) and so did the rhododendrons and azaleas, although no evergreen azaleas bloomed the following spring (1994) except one form of R. kiusianum . In 1995 nearly all plants bloomed, with the earliest R. dauricum starting March 10, and the latest R. prunifolium starting the first week in September.
Generally, the rhododendrons and azaleas moved to Bent Mountain are planted in more sun and exposure than that to which they were accustomed in Fairfax. As a result, they are becoming more compact in growth. As a test, about 20 rhododendrons were planted in full sun in a windswept field. A few of these performed well, most noticeably R. smirnowii . Three plants of this species have thrived in the wind and sun without watering or other care. 'Roseum Elegans' and David Leach's 'Red River' also did well but not with the gusto of R. smirnowii . Leach's 'Mist Maiden' and R. yakushimanum 'Ken Janeck' also did well, reinforcing my already strong belief that these are hybrids of R. yakushimanum with R. smirnowii . Plants of the Exbury form of R. yakushimanum , R. makinoi , and R. hyperythrum and a few others in full exposure declined in two years. Eventually, the plants that declined were moved to a wooded area where they have recovered.
As a general observation, the Orlando Pride elepidote hybrids have been outstanding performers on the edges of the meadow, as have Weldon Delp's lepidote hybrids. A wide range of hybrids (including Joseph Gable's) are doing well with some protection in the woods. Almost all the Pride elepidote and Delp lepidote hybrids bloomed fully after the severe ice storms and -13°F temperature.
Besides the hybrids moved, some 50 different kinds of species (see table) were brought to Bent Mountain. All but one of the species ( R. williamsianum ) have survived and have adapted to the area as evidenced by new growth and regular blooming. Species such as R. minus var. minus Carolinianum Group, R. metternichii (now R. degronianum ssp. heptamerum ) and R. kiusianum are represented here by many forms. It is hoped to expand the species collection both in the kinds and in the different forms of each species.

Subgenus Pentanthera Subgenus Azaleastrum
Section Pentanthera Section Azaleastrum
R. alabamense R. ovatum
R. arborescens Subgenus Hymenanthes
R. atlanticum Section Ponticum
R. austrinum Subsection Fortunea
R. calendulaceum R. decorum
R. cumberlandense (formerly bakeri ) R. fortunei
R. luteum R. fortunei ssp. discolor
R. periclymenoides R. vernicosum aff. Rock 18139
R. prinophyllum Subsection Griersoniana
R. viscosum R. griersonianum (wintered indoors)
Section Rhodora Subsection Pontica
R. vaseyi R. brachycarpum
Section Sciadorhodion R. catawbiense
R. pentaphyllum R. degronianum
R. quinquefolium R. hyperythrum
R. schlippenbachii R. makinoi
Subgenus Tsutsusi R. maximum
Section Brachycalyx R. metternichii (now R. degronianum ssp. heptamerum )
R. amagianum R. smirnowii
R. reticulatum R. yakushimanum
R. wadanum Subsection Williamsiana
R. weyrichii R. williamsianum (didn't like it)
Section Tsutsusi Subgenus Rhododendron
R. kaempferi Section Rhododendron
R. kiusianum Subsection Caroliniana
R. tschonoskii R. minus var. minus
R. yedoense R. minus var. minus Carolinianum Grp.
Subsection Heliolepida
R. rubiginosum Desquamatum Grp.

Subsection Lapponica
R. fastigiatum
R. hippophaeoides
R. polycladum Scintillans Grp.
Subsection Micrantha
R. micranthum
Subsection Rhodorastra
R. dauricum
R. mucronulatum
Subsection Scabrifolia
R. racemosum
Subsection Triflora
R. augustinii, Gable form
R. keiskei

A more focused hybridizing goal will be to try to develop rhododendrons and azaleas that are adapted to the sun and wind of the meadow area here on Bent Mountain. Rhododendron smirnowii and R. brachycarpum (as ssp. tigerstedtii ) are expected to be important parents, along with some already existing hardy hybrids.
As it turned out, hauling the plants in many small loads rather than a few large ones minimized the time the plants were out of the ground. Also, digging, hauling and planting one truckload at a time was just about what we could manage physically before resting for a few days. We believe that the combination of using the container technique, the planting method (with newspapers), and the soil and climate on Bent Mountain resulted in the successful move. The fact that so many plants survived was more than we had dared to hope.
Many of the hybrids moved to Bent Mountain are seedlings grown from our own crosses or seeds obtained from friends and the ARS Seed Exchange. One of these seedlings ( R. maximum x R. arboreum ), a cross by Dr. August E. Kehr, was registered as 'Helen Ring' in 1995. This plant is a vigorous grower, resistant to drought and wind, and bloomed fully after -13°F. In the future we hope to find others that are worthy of naming and registering.
Until most of the plants bloomed in the spring of 1995, some of our neighbors had been somewhat puzzled at the large number of truckloads brought from Fairfax. I explained to one of them, "The rhododendrons that we are bringing to Bent Mountain are quite different from the native rhododendrons growing here." Her answer was, "Well, I'm glad you told me, since the woods are already full of them."
There were a few special people whom we want to thank for their help: Steve Cockerham for the use of the containers; Howard Heisler, Bill Stoddart, Bill Davis and Charlie Ring each of whom helped with one or more truck-loads; Jack and Becky Pilcher who provided free room and board in Roanoke for overnight moves of plants.

George Ring, a member of the Potomac Valley Chapter, is chairman of the ARS Long Range Planning Committee.