Ultra Violet Flowers
by Leonard Perry
by Leonard Perry


In extension I serve as an advisor and consultant to the greenhouse and nursery industry, primarily in Vermont but throughout the region and beyond as well.

I give presentations on my research to the industry, and to home groups. In Research, my focus is "herbaceous perennial production systems".

His website is at  Leonards zone of gardening: home with my trials, generally USDA 4a. Campus in Burlington is 5.

February 18, 2018

Each year the Pantone Color Institute ( — one of the world’s foremost color consulting firms — picks a color to feature. The company’s color for 2018 is the “dramatically provocative and thoughtful purple shade Ultra Violet” (18-3838 on the Pantone color chart). There are quite a few ultra violet and purple flowers that you might consider growing this year as part of this trend, and you can look for them in catalogs and garden outlets this spring.

“The Pantone Color of the Year has come to mean so much more than ‘what’s trending’ in the world of design; it’s truly a reflection of what’s needed in our world today,” said Laurie Pressman, Vice President of the Pantone Color Institute.

Commenting on the choice of Ultra Violet, the Institute’s Executive Director Leatrice Eiseman said that this blue-based purple “takes our awareness and potential to a higher level. From exploring new technologies and the greater galaxy, to artistic expression and spiritual reflection, intuitive Ultra Violet lights the way to what is yet to come.”

Even if these reasons for this purple seem a bit beyond you and your garden goals, ultra violet is a color that can work for most gardens and go with most colors. If you want a low, trailing annual flower, consider the calibrachoa Superbells Grape Punch or the verbena (or vervain) Superbena Dark Blue. These get 6 to 12 inches high and one to two feet wide. More upright, but still only one to two feet high, is the Angelonia (known as a summer snapdragon, though it’s not actually a snapdragon), Angelface Blue. Of the many purple petunias, ‘Wave Purple’ is a popular and good choice.

For perennial flowers in the ultra-violet to purple range, consider one of several perennial salvias such as ‘Burgundy Candles’, ‘Caradonna’, ‘East Freisland’, ‘Marcus’, ‘Merleau Blue’ or ‘Violet Riot’. Most are in the two-foot-high range, need full sun or close to it, are hardy to at least USDA zone 4 (average winter minimum of -20 to -30 degrees Fahrenheit) and bloom in early summer — some all the way through the summer. These perennial salvias also are attractive to pollinators, are generally deer resistant and make good cut flowers.

There are some delphiniums in various purple shades, such as ‘Purple Passion’ and ‘Pagan Purples’, which are hybrids originally from Dowdeswell’s in New Zealand. Yet they are cold-hardy to at least zone 4 and have sturdy stems four to five feet high that don’t need staking. ‘Black Knight’ is a similar height and is one of the plants in the traditional Pacific Giants series.

Another in this series, a bit lighter purple, is ‘King Arthur’. ‘Delphina Dark Blue’ is purple with a white center or “bee” as it’s called with these plants. It blooms early to midsummer and reaches only about three feet high.

There are several dark purple-flowering clematis vines for climbing up a trellis, post or other support or for meandering up through a shrub. Most grow at least into USDA zone 4. ‘Jackmanii’ or Jackman clematis blooms much of the summer, growing 10 feet or more, and is a well-known and well-loved cultivar. This hybrid of two species (lanuginosa and viticella) has been around since the 1800s. The newer ‘Happy Jack’ is a shorter version of Jackman (six feet or so), with bigger flowers and perhaps slightly less hardy. Also shorter than Jackman are the violet-blue ‘Chevalier’ (up to six feet) and the even shorter violet-blue ‘Guiding Promise’ (up to four feet).

There are many other perennial flowers in shades ranging from purple to ultra violet. Carpet bugle (Ajuga) cultivars are low growing and make durable groundcovers, but in many gardens they may be root (or stolen) invasive. False indigo (Baptisia) blooms in early summer and includes ‘Royal Candles’, a royal-violet introduction from Plant Delights Nursery in North Carolina. ‘Sarastro’ bellflower (Campanula) is a selection from the Austrian nursery of this name. It has large, hanging, bell-shaped flowers of deep purple-blue in early summer, on 18-inch-high flower spikes. Perennial geranium Rozanne was a Perennial Plant of the Year winner, grows at least to USDA zone 5 (minimum -10 to -20 degrees Fahrenheit) and often into zone 4, and grows one foot or more in height and two feet wide, with violet-blue flowers in early to midsummer.

Irises are a large group of species and cultivars, many in reddish purple shades. One bearded iris that more closely fits the ultra violet color is ‘Rhinelander’, described sometimes as a mauve grape color. The Siberian iris is one of the easiest perennials to grow: it is hardy, takes wet as well as drier soils and is beset by few pests or problems. ‘Ruffled Velvet’ is a classic cultivar with rich purple-violet flowers in early summer on stalks about three feet high.

Don’t overlook the fall asters, many of which come in colors ranging from purple to ultra violet, are generally quite hardy, and provide food for pollinators when not much else remains.

The traditionally tall (4 to 5 feet) New England asters often can be found in shades of purple. Aster Kickin Purple is a recent introduction from the Netherlands, making a mound about 18 to 24 inches high and slightly wider with violet blue flowers in late summer into fall. It is good in containers but is only hardy to USDA zone 5. ‘Eventide’ flowers of this New York aster species are often described as lavender-purple and appear in the fall on plants up to two-feet high and less than that in width.

You may well find other purple cultivars and species of these and other flowers in catalogs and perennial nurseries. For a dramatic effect, combine them with contrasting colors such as yellows, oranges, pinks or white. Choose perennial flowers that will bloom at various times through the season, or combine them with some annuals for continuous blooms.

  • New Eden
  • Kids Garden
  • Plant a Row Grow a Row