Crazy about Crape Myrtles

Lagerstroemia spp. is an essential flowering shrub and small tree in Zones 6-9, but the genus is now becoming common further North. I observed healthy flowering plants in St. Louis; Cincinnati; Philadelphia; Columbia, Mo.; Greenwich, Conn.; and on Long Island.

Plants have flowers on new growth from May (depending on the location) or June into September, and if spent flowers are removed, a new flush develops in four to six weeks. In the Dirr garden, three floral flushes occurred on the earlier-flowering crape myrtles like ‘Cotton Candy’ now Pink Pig. The flower buds are beautiful, rounded in outline, often glistening red to purple. Richly pigmented bark – cream, tan, to rusty cinnamon – sheathing and exfoliating, contributes to year-long aesthetics. Full sun maximizes flowering. Once established, crape myrtles are forever. I experience magnificent specimens in old gardens and derelict homesteads. Powdery mildew and Cercospora leaf spot are the major diseases with a few insects (aphids, flea beetles, granulate ambrosia beetle) occasionally surfacing. There is also a new scale insect that has been identified in Louisiana and Texas.

Egolf’s work inspires

The great Dr. Donald Egolf’s (USNA) breeding resulted in 25 introductions, including the Indian Tribe series with ‘Chickasaw’ and ‘Pocomoke’ as true genetic dwarfs. Dr. Carl Whitcomb, of Stillwater, Okla., bred Dynamite (true red) and Red Rocket (true red), which grow 10-20 feet high. Rhapsody in Pink is sterile (almost) and Carl’s Double Feature is sterile with continuous red flowers and a 5½-by-5½-foot frame after eight years in my garden. This year brings Double Dynamite, a sterile, continual blooming, red-flowered shrub in the Play It Again series. The cherry-red flowers continued for 100 or more days in Oklahoma. It’s more heavily branched than Dynamite with wine-colored new growth which darkens with age. This disease resistant cultivar grows 8-10 feet high. The Filligree series (coral, red and violet) from Fleming’s Flower Fields, were touted as cold hardy to -30°F, but I found that was not the case. I got so-so results when I tested the series in Athens, Ga. Flower colors were not particularly rich, and all were terribly susceptible to Cercospora leaf spot, particularly ‘Red Filli.’ Described as 12-18 inches high and wide, but without dieback I estimate 2-3 feet high and wide. All appear to be derived from L. indica.

Advance in foliage color

The Early Bird series (lavender, white and purple) are touted as May flowering (May 15, at Hammond, La., trials) and continuous for three to four months. The series grows 5-8 feet by 3-4 feet. The jury is still out, as they appear to be straight L. indica derivatives. Plant Introductions planted the white (‘JD900’), lavender (‘JD818’), and purple (‘JD827’) in-ground in 2011. They did contract Cercospora, but to date I have not seen any mildew in our Georgia trials. Early Bird Lavender was the earliest to flower in LSU’s Hammond Research Station. It has been the best performer at Plant Introductions. They were bred by John Davy at Panhandle Growers in Florida, and available through Southern Living Plant Collection.

Delta Jazz (‘Chocolate Mocha’) – also available through Southern Living Plant Collection – is a major advancement in foliage color, deep chocolate-purple-maroon and fading slightly by late summer, but still potent. Flowers are bubblegum pink, but lightly, sparsely produced. Foliage (cupped leaves appear herbicide affected) displays high disease resistance. It averaged 6-7 feet by 3-3½ feet in 3 years. Distinctly upright in outline. It will reach 10 feet or greater with maturity. PII and other breeders are utilizing the genes to develop deep purple foliage colors and a spectrum of flower colors. In 2012/13, PII introduced Midnight Magic, with salmon-pink flowers and purple-black, disease-resistant foliage (4-6 or 8 feet high) and Moonlight Magic, with white flowers and purple-black, Cercospora-resistant foliage (8-12 feet by 4-6 feet). The latter will contract slight mildew. Both hold the purple-black foliage color into fall. Midnight Magic is first to flower. Moonlight Magic suffered slight stem dieback in the cold 2014 winter when temperatures reached 4°F in the Athens, Ga., area. For 2014-2015, PII added Twilight Magic to the list of purple-black foliage introductions. The habit is upright, estimating 16 feet high by 8 feet wide at maturity. Flowers are a deep pink, not unlike Delta Jazz, but produced in greater quantities. Foliage is not cupped like Delta Jazz and is highly resistant to mildew and Cercospora. This has been the most cold-hardy of the initial three purple-black introductions. A 2016 introduction, Sunset Magic, is a true cherry-red flower with shiny, dark purple-black foliage (5-10 feet high). Flowers form in prodigious quantities, virtually shrouding the foliage. It is highly mildew and Cercospora resistant. Probably best in Zone 8 and higher.

Southern Living/PDSI introduced new purple foliage cultivars in 2013/2014: Delta Eclipse (lavender-purple) 6-10 feet high by 4-5 feet wide; Delta Moonlight (white), 4-6 feet high and wide; Delta Flame (dark red), 6-10 feet high by 4-5 feet wide; Delta Breeze (pink-lavender), 6-10 feet high by 4-5 feet wide and Delta Fusion (fuchsia), 6-10 feet high, new for 2016. These are from a different breeder (Buddy Lee) than Cecil Pounders’ Black Diamond and Ebony series.

Better flower colors

My University of Georgia program, The Center for Applied Nursery Research, and PII have developed many new cultivars. The compact Dazzle series includes Cherry (red), Dazzle Me Pink (bubblegum), Raspberry, Ruby (red-purple foliage), and Snow (white). The best are Cherry and Dazzle Me Pink. Cherry Dazzle was the first red-flowered, true compact introduction, and it yielded Red Rooster (true red, 6-10 feet high) and Strawberry Dazzle (neon strawberry rose, 3-4 feet high). Cherry Dazzle has been a longtime exceptional performer in LSU AgCenter landscape trials, Hammond, La.

Next came Berry Dazzle, brilliant, lustrous, burgundy new growth, fuchsia-purple flowers in early to mid-June, 3-4 (6) feet high in eight years; Diamond Dazzle, pure white, about 30 inches high and wide in eight years replaced Snow Dazzle; Sweetheart Dazzle, true pink, 2-3 feet high by 4-5 feet wide in eight years, shiny green leaves, spectacular quantities of flowers cloak the foliage in July-August. Both Diamond Dazzle and Sweetheart Dazzle have exceptional resistance to mildew and Cercospora. Diamond Dazzle is the best white-flowering, compact crape myrtle I have observed. Sweetheart Dazzle has foliage similar to Euonymus alatus but narrower and more refined. The true pink flowers are borne in avalanche-like quantities in early to mid-July in Athens, Ga. Why this plant has never taken off is beyond me. The original plant, now 14 years old, is 4 feet by 6 feet and resides at UGA’s horticulture farm.

The Barnyard Collection, introduced through McCorkle Nurseries, includes Red Rooster, Pink Pig (burgundy buds open cotton candy pink, early June, 5-6 feet high, extremely precocious) and Purple Cow (purple flowers, dark green foliage, 5-6 feet high). All have been prone to leaf spot in the Louisiana State University trials at Hammond, La. Red Rooster in the Dirr garden is now 8 feet high and 6 feet wide. The flowers are pure red and produced in prodigious numbers. The new growth is lustrous red-green, maturing to dark green. Cercospora has not been an issue.

PII has used many of the above in breeding and introduced the Magic series, Coral, Plum, Purple, and Red. Abundant flowers, richly saturated colors, compact to intermediate habits, colorful, and disease-free foliage define the group. ‘Red Magic’ is susceptible to Cercospora, especially in production. The ‘Purple Magic’ is the truest, saturated, rich purple this author has witnessed. It sets limited fruits and continues to flower later in the season. Most were derived from Berry Dazzle and have L. fauriei and L. indica genes. A 2015 introduction from PII, Ruffled Red Magic, is resplendent with pure red flowers and petals so large, they cover the yellow stamens. PII’s original name was ‘Red Carnation’ for the almost full carnation type flower. The emerging foliage is reddish tinged, turning shiny dark green. Most exciting is the high degree of mildew and Cercospora leaf resistance. In October at PII, Red Rocket and Dynamite had 40 percent of their original foliage while Ruffled Red Magic had 90 percent.

Garden Debut offers the Princess series (all less than 5 feet high): Kylie – magenta; Zoey – red and pink; Holly Ann – cherry red; Lyla – rose-pink; and Jaden – lavender. None of these are patented, and were developed by Dow Whiting at Garden Adventures Nursery in Missouri. They were introduced in 2013-2014 by Greenleaf Nursery in the Garden Debut brand.

Ball Ornamentals’ (Star Roses & Plants) crape myrtles (introduced 2013) are derived from PII genetics and include Enduring Summer Red, Enduring Summer Fuchsia, Enduring Summer Lavender, Enduring Summer Pink, and Enduring Summer White. All are small (4-5 feet tall) to mid-size with reasonable foliar disease resistance; mildew high, Cercospora less so. Enduring Summer Red is true red with abundant flowers. All are patented and available to any growers as they are not ensconced in a brand. The original plants still reside at PII, and in early July 2016 were in spectacular flower with color dripping from top to bottom.

Newer introductions

Another colorful foliage (maroon, purple, black) collection is the Black Diamond series. They were derived from Delta Jazz and, as I understand the ontogeny, bred by the USDA in Poplarville, Miss. J. Berry Nursery in Grand Saline, Texas, introduced them into commerce. I believe Simpson Nursery in Monticello, Fla., is also involved with the introductions. The collection includes Best Red (some powdery mildew in Arkansas trials), Blush, Crimson Red, Shell Pink, Pure White, (mildew susceptible in Arkansas trials) Red Hot, Purely Purple and Mystic Magenta. Sizes are listed for all at 8-10 feet high and 8 feet wide. All are described as highly resistant to mildew. I have only tested Best Red and indeed the purple-black foliage and red flowers are impressive.

Point of clarification...there are multiple series of purple-black foliage crape myrtles and confusion reigns. Several of The Black Diamond and Ebony series are the same. ‘Ebony and Ivory’ (=Black Diamond Pure White), white flowers; ‘Ebony Embers’ (=Black Diamond Hot Red), red flowers; ‘Ebony Fire’ (=Black Diamond ‘Crimson Red’), crimson red flowers; ‘Ebony Flame’ (=Black Diamond ‘Best Red’), dark red; ‘Ebony Glow’ (=Black Diamond ‘Blush’), blush pink flowers. All are listed as growing 10-12 feet high by 8 feet wide. Safe to state, there will always be some discrepancy in listed sizes, as no introducer can possibly predict the ultimate sizes.

A new series (2015) from Spring Meadow and Proven Winners is the Infinitini series, all listed as 2-4 feet high by 3-5 feet wide. The names reflect the flower colors -- Infinitini Orchid (lavender), Infinitini Magenta and Infinitini Brite Pink. Photos reflect a strong L. indica parentage and a looser habit than some of the compact selections like Cherry Dazzle, Berry Dazzle, and Diamond Dazzle. Time, as always, will be the arbiter of garden worth. This year I obtained Infinitini Magenta and am underwhelmed by flower numbers. This cultivar has a lax, open, arching growth habit. I also noticed a few leaves contracting Cercospora. I plan to assess cold hardiness and in-ground performance as the current plants are in containers.

Another relatively new series (Barista) was introduced by Walters Gardens. Described as cold hardy in Michigan, but the online descriptions as of January 2016 state all die back to the ground in winter in Michigan. So by Dirr’s definition of hardiness, to the stem tips, they are not at all cold hardy, but root hardy, just like herbaceous perennials. The Barista series includes ‘Frappe Pink’ with true pink flowers, 3-2½ feet high by 2-2½ feet wide; ‘Cherry Mocha’ with red shades, 2-2½ feet high by 2-2½ feet wide; ‘Like a Latte’ with white flowers, 1½ -2 feet high by 1½ -2 feet wide, and ‘Sweet Macchiato’ with pink (appear lavender in photo) flowers, 2½-3 feet high by 2½-3 feet wide. All are listed as Zone 6-9 adaptable. I doubt the Zone 6 designation unless preambled by the notation, “herbaceous perennial in Zone 6.”

I was in Pennsylvania in late May and noted a new cultivar, ‘Center Punch,’ which I tracked to Centerton Nursery. It is described as growing 3-4 feet high by 2-3 feet wide, with fruit punch red flowers and compact habit. Additionally, Garden Debut listed ‘GV1125’ (from Drury University) with crimson-red flowers, burgundy new growth, maturing dark green and compact habit of 3-4 feet high by 3-4 feet wide.

Crape myrtle periodicals

A relatively new publication about Lagerstroemia spp. can be downloaded at http://bit.ly/Clemson-crape-myrtle. It discusses history, species and cultivars, landscape value, diseases and insects, adaptability and culture, maintenance, and form and function. It’s an excellent read and reference, and nursery producers will benefit from the information, as well as gardeners. There have been many new cultivar introductions since the 2011-2012 publication date, and most are referenced above. Also see Manual of Woody Landscape Plants (Stipes Publishing) and Dirr’s Encyclopedia of Trees and Shrubs (Timber Press). The latter has 12 pages of photos and text of newer cultivars.

Also read the article by Dr. Gary Knox in The American Gardener 93 (6): 14-19, 2014. I visited Gary’s trials in North Florida where he has evaluated 126 cultivars. His article presents the most up-to-date information on the subject.

Two websites with cultivar information include the National Arboretum’s checklist http://bit.ly/USNA-lagerstroemia and Texas A&M

Department of Horticulture’s list http://bit.ly/TAMU-crape-myrtle.

The Dirr Manual of Woody Landscape Plants (2009) and Encyclopedia of Trees and Shrubs (2011) discuss many of the old reliable cultivars including all Dr. Don Egolf’s great introductions. There is abundant information in both tomes on culture, maintenance, diseases and insects.

The constant stream of introductions is both exciting and frustrating because there is no reasonable process/methodology to properly evaluate. At their best, every crape myrtle looks good to the casual observer. I visited the U.S. National Arboretum in June 2016 and witnessed the original plant of ‘Natchez’ still standing tall with beautiful cinnamon-brown bark after 40 years. I guarantee that many of those discussed in this article will disappear in a few short years. I also guarantee that there will be many more to come. Crape myrtles are forever.

For more:www.usna.usda.gov/Newintro/index.html; www.lacebarkinc.com; www.flemingsflowers.com; www.southern livingplants.com; www.canr.org; www.plant introductions.com; http://mccorklenurseries.com; www.lsuagcenter.com; www.gardendebut.com; www.blackdiamondblooms.com; www.springmeadownursery.com; www.walters gardens.com; www.centertonnursery.com.

Dirr is a former horticulture professor at the University of Georgia, a co-founder of Plant Introductions Inc., and a consultant with Bailey Nurseries.

The opinions expressed in this article are the author’s own and do not necessarily reflect the view of Nursery Management or GIE Media.