Some Like It Hot
The Dallas Arboretum is a world-class facility consisting of 70 acres of assorted plant collections, including hardy ferns, holly, palms, Japanese maples and azaleas, as well as container trials and annual beds. The trial gardens were introduced in 2003, consisting of baskets, containers, perennials and annual trial beds.
I have visited this arboretum since the inception of the trial gardens and look forward every year to visiting in midsummer to evaluate perennials and annuals for summer performance. The temperatures in the Dallas area are extreme, with average highs of 95° F and lows of 74° F degrees during June, July and August with excessive humidity.
The plants I focus on this month were successful in the arboretum’s landscape beds this summer. Many of the varieties used this year are Texas Superstars. These varieties have been trialed and have performed exceptionally for at least three years in various locations in Texas. Growers have utilized these plants for many years, and they have demonstrated resilience and durability under extreme summer conditions.
The selection criteria include foliage quality, floriferousness, heat and drought tolerance, and architecture. The most essential attribute is color. It is imperative these plants provide eye-catching color for the display beds throughout the summer. In addition to the Texas Superstar designation, most of the plants on this list are also considered Flame Proof varieties, certified plants by the arboretum that perform from spring to fall under the extreme conditions of Texas summers. The plants selected are not new for 2018. Many have been available for many years, and some are more recent, but they all share one significant attribute: performance!
This coleus variety was stunning in full sun and is an excellent plant for high impact, low maintenance and vivid color. The eye-catching reddish orange color is nonfading, and the plant is bold in the landscape and later to flower. It was used as a backdrop with complementary plants including ipomea Lime, zinnia Profusion and canna Cannova. This coleus matures at 30 to 36 inches and is a perfect companion plant. Coleus ‘Campfire’ is pictured above.
Coleus ‘Red Head’
‘Red Head’ and ‘Campfire’ are part of a collection and are Texas Superstars and Flame Proof varieties. This variety is the best red in the collection. It was used in full sun in the Arboretum beds and provided stunning nonfading color, excellent contrast, height and texture. This is a complementary and versatile coleus that performs in high heat, humidity an full sun and has excellent for containers and landscape beds.
Canna Cannova Series
This first seed F1 canna is extremely versatile with application in 4-inch and large container programs, as well as landscape beds. The arboretum used many colors in beds and containers, and with seven
colors available you can mix and match with other landscape components. The series was used as a thriller in large containers and in the background of many beds. The plant’s architecture, drought tolerance and flowering capacity are striking attributes and add value to a landscape.
We have many series to choose from in the industry, including standalone varieties from rhizomes, seed, and tissue culture. The genus is indispensible to the landscape industry.
Alternanthera ‘Little Ruby’
This vegetative variety has been on the market for many years and remains a top performer in landscape beds and containers. This is a Texas Superstar plant that is used as a ground cover or a spiller in full sun. It produces rich shades of burgundy and purple foliage on a compact, prostrate habit. It is a tough plant with outstanding heat and drought tolerance.
Four outstanding introductions for 2018 are ‘Purple Prince’, ‘Choco Chili’, ‘Little Romance’ and ‘Plum Dandy’. I saw many of them in multiple trial sites this summer, and they all exhibited many of the same attributes of ‘Little Ruby’, including non- fading burgundy-purple foliage, heat and drought tolerance, and vigor. The choices are many, but the results are the same: outstanding summer performance.
Celosia ‘Fresh Look Red’
This variety has stood the test of time, having been a 2004 All-America Selections winner and breakthrough variety. This celosia continues to perform with a strong upright habit, large inflorescence, uniformity, and heat and drought tolerance. The rose-red plumes are bodacious and engender the “wow” factor necessary in landscape plantings. Since 2004 we have had many excellent celosia introductions to choose from including plumosa, cristata and cockscomb types, but this series continues to impress.
Evolvulus ‘Blue My Mind’
This large flowering, true blue evolvulus is one of the the most heat tolerant plants in the Proven Winners collection. It has proven success in the south for many of its attributes, including vibrant blue flowers, short internodes, cleanliness, uniformity, heat and drought tolerance, and prolific flowering. It is used in many Proven Winners combo recipes and is an excellent component in combination planters. Application at the arboretum was in mass plantings and mixed containers.
Torenia Summer Wave Series
This Flame Proof plant series has been available for many years. The plants were used in many areas at the arboretum in containers and beds. The five colors in the series can be planted in sun or shade, and the tubular flowers provide strong color and continue to flower throughout the summer. This early blooming series is trailing, vigorous and self-cleaning, spreading over 3 feet with a dense mounded center. The plants are adaptable in sun or shade. The series tolerates drought, high humidity and extreme heat.
Gomphrena ‘Pinball Purple’
This is the first vegetative gomphrena on the market and exhibits the same excellent characteristics as current seed varieties, including All Around, Fireworks, Qis, Las Vegas, Audray, Ping Pong, Gnome and Buddy. Many of these are certified as Flame Proof varieties by the arboretum.
The Pinball series is available in three colors: Purple, Snow Tip Lavender and White. Purple was used in many con tainers and mixed beds this summer. It was mixed with zinnia ‘Profusion Yellow’ in beds, and the contrast was stunning. This series matures at 12 to 18 inches with an excellent mounded habit and vibrant globe shaped flowers. As with all gomphrena, it is drought and heat tolerant.
Portulaca ‘Cupcake Yellow Chrome’
I saw this plant for the first time in the Texas A&M trial in 2012, and I was impressed by the vibrant yellow color this portulaca produces. As I gazed across the field trial that day, my eye was attracted by this variety. The Arboretum used it in large sweeping beds this year and the color was stunning. This variety has excellent branching and is incredibly floriferous. The Cupcake series is comprised of five colors and a new upright compact series will be introduced for 2018 production.
Salvia Wendy’s Wish
This plant originated in Australia and was introduced by Plant Haven in 2007. This salvia hybrid has reddish magenta tubular flowers with striking magenta stems. The inflorescence rises above the foliage providing color impact in landscape beds. This is a striking border plant, maturing at 3 to 4 feet with dense glossy green foliage. It is extremely drought tolerant, requires full sun, and is a hummingbird magnet. ‘Wendy’s Wish’ is certified as a Flame Proof plant.
Scaevola ‘Surdiva Classic Blue’
Surdiva is a Certified Flame Proof Plant series for many reasons. The Classic series is vigorous but is characterized by short internodes, floriferousness, large fan flowers and profuse flower canopy. It has extreme heat and drought tolerance. The series is comprised of Blue, Pink and Light Blue. It is a low maintenance, nonstop flowering series that continues to provide exceptional color in the landscape throughout the summer. Suntory has recently added four additional varieties that provide a more compact growth habit for containers.
Begonia Whopper Series
This begonia series was classified as a Texas Superstar in 2016 and also received Flame Proof status at the arboretum. It is characterized by large foliage and flowers, and matures at 30 to 36 inches in landscape plantings. The series performs in sun and is adaptable in shade situations. The plants are vigorous with extra large flowers positioned above the foliage, which creates a colorful display throughout the season. The arboretum used the bronze leaf red this year in areas with understory trees and shrubs as well as in large sweeps in full sun. It is versatile and durable and demonstrated excellent summer performance in multiple trials in the south and north. The series is comprised of bronze and green leaf varieties.
I would be remiss if I did not mention the Big and Megawatt series that also continued to perform through late August in southern and northern trials, in containers and landscape sites. There are some differences in leaf and flower size as well as growth habit, which should be considered when making decisions on production applications. These three series are summer survivors with outstanding landscape performance.