Daylilies - An Introduction

People often ask me which plant in my garden is my favorite.  That’s a tough one.  I usually tell them I can’t name a favorite, although I have discovered a few that are not my favorites.  But, if forced to name favorites, daylilies would be sure to be on that list.
 

"Destined to See" daylily; EV; 24 inches tall, early bloom

Daylilies are tough, versatile, long-lived, low-maintenance, drought tolerant, and beautiful perennials.  I’m not sure you can ask for much more than that from any plant.  Add to that the fact that there are nearly 40,000 varieties of daylilies, which sport some pretty cool names, in virtually all colors except blue and pure white, and they are nearly irresistible.

Daylilies are not true lilies.  They are members of the genus Hemerocallis, which literally translated means day (hemera) and beauty (kallos), or “day of beauty”.  They came by the name Hemerocallis  or“daylily”, because each blossom, as beautiful as it is, lasts only one day.  A blossom typically opens in the morning, reaches its peak by mid-afternoon and begins to fade in the late afternoon heat, closing up by late that evening or early the next morning.  Some newer varieties have been bred to be a little more long-lasting, with the buds opening in the evening and remaining open until the following evening.  These night-opening cultivars also tend to be some of the most highly fragrant daylilies.


Brushed With Bronze, 24 inches; DOR

While it seems like a waste to plant something that will only bloom for one day, that’s just not true with daylilies.  High performing daylily cultivars put up many “scapes”, or flower stalks, with many buds per scape, and can produce several hundred flowers per season.    These scapes come in different heights, ranging from the miniatures that are less than a foot, to giants that reach heights of nearly four feet.  The flowers come with ruffled edges, plain edges, and  glittery,  diamond-dusted edges; they might have “eyes” in the center of the bloom and a throat which may be a highly visible different color from the petals.   Some daylilies have different color sepals (the bottom three segments of a dayliliy flower), and petals (the top three segments of the daylily flower)  on the same blossom and are called bi-colors.  Flowers range from tiny to gigantic; they may have curled under petals or long, narrow, spidery looking petals; some have double flowers.  Many of the newer hybrids are highly fragrant.  There is truly a daylily style and color for every taste.

There are also daylilies that bloom early in the season, in the middle of the gardening season, and those that bloom late into the fall.  There are some that bloom early and then re-bloom later in the season, although those are a challenge in northern climates.  Often, the growing season just isn’t long enough to allow that second bloom.  There are some that put up so many scapes and are reliable, early enough re-bloomers, that they appear to be “ever-blooming”, like the Stella d’Oro, Happy Returns and Rosy Returns cultivars.

 Daylilies also are distinguished by growth habit.  There are three classifications of growth habits:  dormant, evergreen and semi-evergreen.  These are listed in the daylily description as DOR, EV, or SEV.  In northern climates, dormant daylilies are the most reliable.  Daylilies of this class go completely dormant in cold weather.  They lose their foliage completely, usually just after frost.  They overwinter with foliage buds, called “resting buds”,  just beneath the soil surface and these foliage buds resume growth in the spring.  Because all signs of life are below ground in cold weather, these tend to tolerate the temperature extremes of northern winters better than semi-evergreen or evergreen types.

Evergreen daylilies retain their foliage throughout the year.  In our cold weather, this foliage looks like a pale green, somewhat slimy mass of tangled leaves.  They do not set the resting buds that dormant daylilies set and may be damaged by the extreme cold and the freeze and thaw cycles of northern winters.  For that reason, many northern daylily growers tend to avoid the evergreens, although hybridizers are working all the time to create a daylily that has the best of the evergreen traits but still withstands the nasty winters.

Semi-evergreens are daylilies that don’t quite fit either the dormant or evergreen categories.   Their foliage dies back partially but not completely, in warmer climates.   In reality, in my garden, most every daylily has a growth habit that appears to be dormant.  In the depths of winter, if I look at my daylily foliage, I generally only see black, frozen leaves with no signs of life.  In the spring, they all come back with nice, fresh green foliage.  In warmer climates, or even here in a very mild winter, where evergreen and semi-evergreen daylilies do not go dormant, they may look pretty ratty come spring, with a mix of cold damaged leaves, dead leaves and fresh spring growth.  I usually end up cutting all old foliage back to the ground, even if it did stay partially green over the winter. 

The key to successful over-wintering is not so much whether the foliage is able to stay green or not, but whether the crown is hardy to whatever zone it is grown in.   That said, I do find that my evergreens and semi-evergreens are a little slower to bloom than they might be in warmer climates – they need to play “catch-up” with the foliage that’s been damaged in the winter rather than start putting their energy into scapes and buds.

We’ll talk more about daylily terminology on Thursday.