Growing Peonies in North Carolina
Jim Carson, APS Member — Clayton, North Carolina
A DETAILED REPORT OF MY SOIL PREPARATION AND PLANTING
Described in this article are my different attempts at preparing the best bed for my peonies.
I have seven beds about 16- x 22-feet. This area holds over 300 plants of 115 varieties. Some of the late bloomers produce tremendous plants, but their blooms get damaged by heat. We can reach 95° F by the first week in May. 'Elsa Sass' in 12 years has never produced a flower on the plant. The two plants are over 3-feet tall and wide with quarter to half dollar-sized buds (photo below left), but they do not open.
'Sarah Bernhardt' and 'Ann Cousins' also have trouble with their buds opening. 'Ann Cousins' is, however, worth any complication and fully blooms one in two or one in three years. The flowers are spectacular! 'George W. Peyton' is another marvelous plant, but the buds never open. Again, I blame the heat.
All of the plants produce 20–30 bloom stems and side buds often appear on particular varieties (photo below right). 'Coral Charm' and 'Illini Warrior' have 30+ blooms every year, but no side buds.
When the bare root arrives from the supplier it may or may not bloom the first year. A two-year plant, 'Prairie Charm', did not bloom the first year. This year (its second), it produced 12 blooms and is 36-inches wide and 2-feet tall. 'Prairie Butterfly' is also a 2-year plant, 36-inches tall with 15 blooms. All of this year’s second year plants were eye popping!
The soil of each planting bed is extremely important for a spectacular plant. These beds are located in Clayton, North Carolina—Zone 7-8 boundaries of the USDA Plant Hardiness Map. The summer may reach 105° F and the winter may bring 6° F. There is also the chance of late freeze, severe thunderstorms with hail and wind and early 90° F plus temperatures, which will damage some blooms. In these beds no permanent damage has been observed, but there is disappointment when the flowers are damaged.
Plant supports distract from the natural look of the garden but 90% of these plants have supports; i.e., even Singles like 'Sea Shell' and 'Krinkled White'. I make the supports from cinder block stabilizers.
I have modified bed preparation as deficiencies were observed. The first two beds were raised 2-foot beds. Purchased “top soil” was used and humus was placed 18-inches deep in a 3-foot hole. The third bed had a 22-inch wide x 2-foot deep trench with a 6- x 6-inch timber placed around the perimeter. Total depth was 30-inches and plant spacing was also 30-inches. A space of 18-inches separates the trenches. I acquired better top soil for this bed and no humus was used. 'Ann Cousins', 'Florence Nicholls', 'Krinkled White', 'Arcturus', 'Reine Hortense', 'Charm', 'Elsa Sass' and 'Baroness Schroeder' are in this bed and grow 3-feet tall (photo below left). Supports are definitely needed. The three early beds relied on someone else’s definition of top soil. There were no rocks, but there was Bermuda grass.
Beds 4–7 are all on a sloping hill. Bed 4 is 5-sided, similar to baseball’s home plate. Trenches 30-inches deep and 24-inches wide were dug. One foot of un-dug dirt was left between the trenches to serve as a path. The dirt from the trenches was sifted through ¼-inch hardware cloth. The sifted dirt was layered roughly 4-inches in dirt to 6-inches aged horse manure containing wood shavings. The mixture was blended in the trench and packed. Walking and hand tamping were sufficient for packing. Wood shavings were present in the horse manure but the manure content was probably 75%. Testing of the beds by the state agriculture department showed that the zinc from the manure was within safe limits and that too much manure had not been used. The wood shavings from the stalls help with retarding packing, increase water absorption and increase the humus content. Grub insecticide and lime were also layered in the trench.
Bed 5 was prepared like Bed 4, with one exception. The path between the rows was dug to a depth of 1-foot. The un-dug path in Bed 4 retarded easy root growth and hindered water absorption. Various peonies in Bed 4 wanted to send their root laterally into the path, instead of vertically into the prepared bed. This observation compelled me to create a more desirable lateral environment.
Beds 6 and 7 were prepared by removing all of the dirt in the 16- x 22-foot bed to a depth of 30-inches. The low end of the bed is above ground by some 20-inches while the high end is even with the grade in Bed 6 and below grade in Bed 7 . All the rock, down to ¼-inch, was removed and manure with shavings was added, mixed and packed with lime and insecticide, as earlier described (photos below right).
Beds 4-7 were allowed to age and equilibrate for three to nine months, depending on the difference between completion and planting time. Even though packing was attempted, Beds 6 and 7 settled 1-2-inches in the first year; i.e., first winter. All the beds were initially over-filled, making the final grade level after settling. A level bed helps with uniform watering and fertilizer distribution.
When planting the bare roots in the fall, a hole 30-inches deep, with a 2-foot diameter was dug. For me, planting in late October is better than planting in September. September planting may have time to sprout and grow 6- or 8-inches before the freeze kills the sprout. The root will sprout again in the spring but the plant will be stunted. Roots that have been refrigerated prior to shipping are likely to sprout in this growing area. Eighteen inches of a good manure/wood shaving, a small handful of lime and ⅛-cup of equal amounts of phosphorus pentoxide and potash were placed in the hole and packed. A mixture of 50/50 prepared bed dirt to manure shavings was mixed in a wheel barrow and used to fill the remaining hole containing the new plant. North Carolina Agriculture Soil Analysis indicates humus content to be between .6-.7%. The pH is 6.8. The new fall plants received ¼ cup of 50/50 phosphorus pentoxide/potash and ⅛ cup of calcium nitrate distributed in a 15-inch diameter circle around the new root at a depth of 2-inches. Older plants only received the 50/50 phosphorus pentoxide/pot ash mixture in the fall. It is also distributed in a circle, 2-inches deep around the crown. All plants in late February receive the “fall planting” amounts for new plants. When moss is observed, lime is added to maintain a pH of 6.7-6.8. The dirt in this locale is not “farmer’s dirt”. It is excessively rocky and marbled with red or grey clay. Twenty miles east of Clayton, wonderful black agricultural dirt is found. In the area where red clay is abundant one can mix clay dirt with commercial wood products containing gypsum at a 50/50 ratio. Such a product is found in most large gardening outlets. Bed 8 (photo below) which is not previously mentioned is heavy red clay and the commercial product was mixed with the clay. Moreover, this red or grey clay can be found throughout North Carolina, upstate South Carolina and in northern Georgia.
Below is a list of peony cultivars that I grow. An asterisk (*) indicates a marvelous plant with outstanding blooms. These varieties bring a particularly large smile to my face!
* 'Amalia Olson'
* 'Ann Cousins'
'Attar of Roses'
* 'Baroness Schroeder'
'Boule de Neige'
'Bowl of Beauty'
* 'Catharina Fontijn' ["There are many variations of this name. This is the correct one." — Reiner Jakubowski, APS Registrar]
'Claire de Lune'
* 'Coral Charm'
'Duchesse de Nemours
Eden's Perfume [unregistered]
* 'Festiva Maxima'
* 'Florence Nicholls'
* 'Frances Willard'
* 'Garden Treasure'
* 'Gay Paree'
'George W. Peyton'
* 'lllini Warrior'
* 'Krinkled White'
* 'Lady Alexandra Duff'
'Louis van Houtte'
* 'Madame de Vernéville'
'Many Happy Returns'
* 'Monsieur Jules Elie'
'Monsieur Martin Cahuzac'
'Paul M. Wild'
'Pehrson’s Violet Frisbee'
Red Magic [unregistered]
* 'Reine Hortense'
'Ring of Fire'
'Roy Pehrson's Best Yellow'
* 'Wine Angel'