Daylilies for every day

They may only bloom for a day but their colorful flowers are a must in any garden.

Daylilies, also known under their scientific name Hemerocallis, are some of the most interesting plants to include in a perennial garden. In general, they are resilient and easy-to-grow while bringing gracious foliage and colorful flowers to the landscape. For these reasons, some gardeners even describe daylilies as the perfect perennials. Others find them annoying because of their short-lived flowers (a day or two) which become sticky, dry or mushy when they fade.

Let’s learn a little more about daylilies

There’s definitely more about them than the regular orange tawny daylily (Hemerocallis fulva) naturalized along roads in the northeast and even considered as invasive in some areas. Daylilies are hardy almost everywhere, from zone 1 to zone 11, making them versatile plants in the landscape. They also are very tolerant in terms of soil and light requirements, but they prefer slightly moist, well-drained and organic soil with 4-6 hours of sun daily. A yearly addition of compost is all it takes to keep them happy.

In my garden, I proudly cultivate about 70 cultivars of daylilies, though this number pales in comparison to the approximately 35,000 registered cultivars out there. Nevertheless, my backyard islands burst into vibrant displays of yellow, orange, and salmon pink hues all at once in mid-July, eliciting admiration from visitors as they traverse the mixed borders.

I particularly appreciate how daylilies bloom in mid to late summer, serving as lovely companions to my peonies long after their show has ended. Among the peonies, I favor tall scapes of light pinks positioned in the middle of the borders, while the shorter new tetraploids with contrasting eyes take their place at the front. However, some cultivars have a tendency to become rapidly invasive, necessitating vigilance to prevent them from outgrowing their allocated space and overtaking other cherished plants. Should this occur, daylilies can be easily moved and divided in the spring. Their underground system comprises rhizomes, subterranean stems, from which thin roots emerge.

Typically, their funnel- or trumpet-shaped flowers are borne on long-stalked clusters, called scapes, above narrow, sword-shaped leaves that are grouped at the base of the plant.

Some daylily plants will form seeds as a result of self-pollination. The green capsule matures in late fall. Hybridizers prefer cross-pollinating by hand to select parental characteristics. Seedlings may bloom in 2 to 4 years and will never be true to parents. Pruning the flower stalks as soon as they are done blooming will maintain a neat clump of foliage.

Even if I tend to think of them as mostly late bloomers, daylily cultivars are categorized as early, mid-season and late, very similar in aspect to peonies, but their earliest blooms start in late spring. Some are also described as repeating and fragrant. My choice as the most fragrant is the early bloomer yellow daylily, Hemerocallis lilioasphodelus (previously known as H. flava).

Daylily flowers also come in different shapes: spider, round, star, double, serrated, spatulate, etc. They may show a single hue, or be bicolored or multicolored. Finally, their foliage may die back every fall or stay evergreen year-round. I do, however, cut back all their foliage in late fall.

All about daylily genetics

The classic daylilies are diploid, meaning they have the original number of 2 sets of chromosomes forming their genetic makeup. But hybridizers over the years have developed triploid daylilies with 3 sets of 11 chromosomes and tetraploids with 4 sets of 11 chromosomes. Most of these are the result of the use of colchicine which is a genetic mutation agent. Triploids are infertile (not setting viable seeds). We can distinguish tetraploids thanks to their distinct ruffles on thicker petals and contrasting markings in the eye zone (the colored band between the throat and the tip of the flower), expanding the usual hues of yellow, orange, and red, sometimes with bolder hues in the dark violet, fuchsia and maroon. Their only shortcoming is their tendency to develop mushier petals as they fade than diploids.

Your ordinary garden center may not provide you with all these details when you buy a plant, still a quick web search of cultivars will furnish all this interesting information. My preferred source is the Daylily Database compiled by the American Daylily Society. I also favor the British National Gardening Association database under garden.org because the description is accompanied by many photos contributed by members. Evidently, all my daylilies are listed in my excel sheet, labeled in the garden and pinned in a section of my Pinterest.

Buying daylilies

Most nurseries will offer a range of daylilies that are suitable for your region. Do not buy the tawny daylily species (H. fulva) and give preference to tetraploids in areas where H. fulva is considered invasive. You may also buy online from specialized growers as they offer a larger selection of bare rhizomes. Avoid buying imported rhizomes in bags at big box stores because they may be mislabeled and of inferior quality.

There are many hybridizers that will also offer a great choice of their own plants. Some will not even be labeled or registered and you can visit their fields when they are in bloom and make your choice.

Newly registered varieties are more expensive than older ones and larger clumps often cost more. Daylilies grow so quickly that you should consider acquiring smaller plants at first. Before buying daylilies, consider their future location in the border and, for what they will be used. For instance, the shorter and smaller but very prolific bloomer yellow ‘Stella de Oro’ is a favorite of landscapers when planted as edgings. Excentric tetraploids like ‘Vegas Jackpot’ and ‘Born in California’ are outstanding as statement specimens.

As in the peony world, there are some serious daylily collectors. The latest tetraploid hybrids may cost as much as $500 because they need to be propagated vegetatively in smaller quantities at first, but, as with any other plant novelties, prices go down with time, even being offered at low prices during fall clearance sales. Because I don’t consider myself a diehard collector, I go for the more reasonably priced cultivars. Potted daylilies may be transplanted at any time, as long as it is a few weeks before frost. Make sure you water them regularly after transplanting. Allow at least 18 inches around. New plants will bloom during the first summer if planted early.

Daylilies in vases

Because of their short-lived blooms, daylilies are not necessarily great cut flowers. If you wish to cut a stalk, select one with unopened buds. Their ephemeral beauty is perfect for a simple display or for making a stunning but brief statement in any arrangement with summer blooms such as lilies, dahlias and zinnias.