Text by Christopher Darrow for the July/August 2016 issue of Horticulture.
The desire to create a garden that stands out from the typical landscape can lead gardeners to pass by certain plants, because they’re too common or they’ve acquired a certain reputation. Such is the case with daylilies (Hemerocallis spp. and cvs.). We’ve seen these ruled out of planting lists because they’re too refined or too gaudy, too short, lacking in long-season appeal . . . the reasons go on. Daylilies are one of the most diverse and heavily hybridized perennial flower in existence. The American Daylily Society recognizes over 60,000 registered cultivars, with variations of color and color patterns and flower forms and sizes. Looking at this data, it’s admittedly hard to imagine what else one could expect to find new or different in a daylily.
However, there are overlooked attributes in daylilies, including details of foliage and scape (flower stem). Species and certain cultivars that exhibit interesting leaves, astounding scape height or unexpected bloom time can dazzle us in distinctive gardens, while retaining their reputation as low-maintenance plants.
The toughest of the tough
Species daylilies are perfectly suited for any location that is less than perfect for growing flowers. Forget the need for special coddling that so many of the newer showy daylilies require. While sometimes a bit slow to settle in and achieve their true splendor, they are virtually indestructible once established. They are highly drought tolerant, but they will survive periods submerged in water and they will even outcompete goldenrod and tall weeds.
Lemon-yellow trumpet flowers, typically fragrant, characterize Hemerocallis citrina. There are a large number of species variants, in part because the original species has been cultivated for so long it is difficult to absolutely figure out which variants are true species types originating from the wild or early hybrids that occurred naturally or through hybridizing. Their variations include scape height, flower shape and bloom time.
The H. citrina types offer a great range in flower types, from spidery to trumpet shape, and various shades of yellow. They all can be relied upon for their outstanding foliage, which remains impeccably clean, as they seem to be resistant to leaf diseases. All have blue-green glaucous leaves, and the new shoots that emerge in the spring exhibit a radiant lush coloration that catches the eye from a distance. In the fall the leaves die back to a rich brown, weed-suppressing mat around the base of the plants.
Hemerocallis citrina var. vespertina, H. c. var. thunbergii and possibly H. altissima all fall into the H. citrina complex. These daylilies are unusually tall, with heights of 48 inches or more and over 20 buds per scape. The classic H. citrina is about 48 inches in scape height with a bud count of around 20. The foliage is typically about 24 inches in height and a blue green. Blooming in mid season (mid-July here in Vermont), H. citrina last into August. The vespertina variant is taller, with scapes up to 6 feet and bud counts to 35. The foliage is 30 inches tall. Meanwhile H. c. var. thunbergii looks very similar to H. citrina, but with 6-foot scapes and bud counts of 35 and blooming from late July into late August.
On the other end of the spectrum—at the beginning of the season—are the early-blooming species. All are as hardy and as reliable as bulbs and are frequently recommended to cover the unsightly foliage of spent daffodils. Hemerocallis dumortieri is one such early species. It blooms very early, as early as late May but typically early June here in Vermont. Its yellow-gold trumpet-shape blooms are amazingly fragrant for a daylily.
Reaching taller still
The obvious approach is to hybridize the H. citrina types together and select the most outstanding resulting seedlings. Through hybridizing there has been a number of extremely tall cultivars developed. Old standbys developed in the 1930s by Dr. Arlow Stout, such as ‘Autumn Minaret’ and ‘Challenger’, come to mind. Here in Vermont we have focused on characteristics reminiscent of the species but with certain selected attributes.
‘Towers of Eisenkramer’, a H. c. var. thunbergii hybrid, looms at six-and-a-half feet, with open flowers of clear yellow. Highly fertile (as are the species), ‘Towers of Eisenkramer’ can sometimes flop with the weight of its seedpods.
‘Notify Ground Crew’, with yellow five-inch blooms on six-foot scapes, and ‘Berlin Tallboy’, with orange six-inch blooms on six-foot scapes, are two well-known tetraploid cultivars. Because of the close affiliation with the species colors beyond yellow, gold and orange are rare. ‘Berlin Red Tallboy’ is an unusual tall red daylily from Germany, but it is largely unknown in the United States and as such not much information is known about it at this time.
Another overlooked quality of daylilies is the pigmented scapes, buds and bracts. Through selective breeding, intensively pigmented scales can be produced. There are other later blooming dark-scaped cultivars, such as ‘Sir Blackstem’, but the most classic pigmented scape cultivar is listed as an early bloomer growing 24 inches tall with an evergreen growth habit. Another dark-scaped daylily is ‘From Darkness Comes Light’, an early bloomer with creamy yellow flowers.
The most extremely pigmented daylilies seem to be produced by H. dumortieri. Two cultivars, both unnamed at this point save for the labels ‘4-9-01’ and ‘17-08’, are examples of the degree of pigmentation that can be achieved. The first is lemon yellow with dark scapes blooming in early to mid-June and as such falls into the extra-early bloom category. ‘17-08’ has a more golden bloom, with scapes a deep matt black. Its slightly undulating growth habit makes for a stunning show well before the flowers even open. Interestingly, the pigmentation is stimulated by sunlight; the scapes emerge green but as they are exposed to sunlight they become darker and darker, eventually taking on the intense dark hue that is so striking.
There are some daylilies that have red blooms with dark scapes, as well. Their parentage is not clear, and neither is their color, but the effect is still striking. One could imagine over time selective breeding will bring about dark-scaped daylilies in a variety of flower colors. You see, there are things new in daylilies, after all.
Christopher Darrow manages Olallie Daylily Garden, where he continues the breeding work begun by his grandfather, Dr. George Darrow.