JARS 42n3 - Lengthening The Blooming Season

Lengthening The Blooming Season
Willis Neal Harden, Jr.
Commerce, Georgia

Of the many rhododendrons I have grown over a period of twenty-five years, a disproportionately large number of varieties that bloom late to very late in the season have proved to be "good doers" in our southern climate. At the other extreme of the rhododendron season, a large proportion of early to very early varieties fit into this adaptable category. The late varieties offer more scope because of unpredictable weather here in the early spring, but it is still desirable to extend the season in both directions by adding both late and early varieties to the usual, prevalent midseason ones.

A good show of rhododendrons can be had in north Georgia from the middle of March through the middle of June (with even a few later than that). On August 6th last year, I noted the prunifolium just beginning to open and the auriculatum just finishing its bloom.

This past spring the first blossoms to be seen were on sutchuenense and spiciferum , both open by the middle of March. In previous years, these two have been undamaged by heavy snows. Following these are 'Bibiani', numerous strigillosum hybrids, an early form of aberconwayi and various williamsianum hybrids which bloom here earlier than they are rated.

Late in the season, a trio each of deep reds and fragrant whites furnish a massive display following a lull after the midseason bloomers. The reds start opening the last week in May and the whites in early June.

The first of these reds to open is 'Grenadier' ('Moser's Maroon' x elliottii ), followed by 'Romany Chal' ('Moser's Maroon' x eriogynum ) and 'Kilimanjaro' ( elliottii x 'Dusky Maid'). These three relatives look a lot alike. In this area, 'Grenadier' outshines the other two for truss magnificence, while 'Romany Chal' is the more vigorous grower. However, all three thrive. In my garden, 'Kilimanjaro' is younger (it does however predate the record cold 1985 winter).

Both 'Grenadier' and 'Romany Chal' have the habit of layering the outer limbs and eventually producing a thicket that builds high in the center. I have one 'Romany Chal' that has twenty or more large rooted layers that I plan to separate next winter.

The white trio blooms later than the red, all are tree-like and fragrant. They are discolor , diaprepes , and auriculatum .

The reds show up best with the late afternoon sun shining through the crimson trusses. The whites are best appreciated after the shadows have fallen. All these late varieties should be watered copiously just before flowering to prolong the blossoms in warm weather. In this area, most of the late bloomers require woodland conditions. All should be regularly sprayed with fungicide, a practice unfortunately not commonly adhered to with the result that plant losses are mistakenly attributed to winter damage.

R. aberconwayi, early form R. 'Temple Bells' in early April
R. aberconwayi , early form
Photo by Willis Neal Harden, Jr.
'Temple Bells' in early April
Photo by Willis Neal Harden, Jr.
R. discolor tree 'Romany Chal', R. bakeri in foreground
A tree of R. discolor
Photo by Willis Neal Harden, Jr.
'Romany Chal', R. bakeri in foreground
Photo by Willis Neal Harden, Jr.

The following varieties grow well in my garden and can be recommended for this area:

Early species; aberconwayi (early form), arboreum (pink and white forms), augustinii , calophytum , hippophaeoides , irroratum , pemakoense , racemosum , spiciferum , sutchuenense , vernicosum (early here).
Early hybrids; 'Babylon', 'Bibiani', 'Chapmanii Wonder', 'Etta Burrows', Grace Seabrook', 'Matador', 'Maxine Childers', 'Paul Lincke', 'Red Majesty', Temple Bells'.
Late species; bakeri , diaprepes , discolor , prunifolium .
Late hybrids; 'Aladdin', 'Angelo', 'Autumn Gold', 'Aunt Martha', 'Ayah', 'Azma', 'Cheyenne', 'Damozel', 'Evening Glow', 'Frank Baum', 'Good News', 'Grenadier', 'John Coutts', 'Kilimanjaro', 'Lodauric', 'Old Copper', 'Romany Chal'.

R. 'Grenadier'
Photo by Willis Neal Harden, Jr.

Mr. Harden has been growing several hundred species and hybrid rhododendrons and azaleas for more than twenty-six years at Commerce, Georgia (60 miles NE of Atlanta). He is developing a nursery stock of plants adaptable to the Georgia climate.