Helleborus for Colorado

Posted by Jim Klett – CSU Professor and Extension Landscape Horticulturist

In our 2 winter, 3 growing season perennial trials at Colorado State University we have been trialing numerous species of Helleborus for five years.  I have been extremely impressed with their performance and hardiness and adaptability in our trials.  The common name is lenten rose and they generally grow 15-18 inches in size and 15-20 inches or more in width.  Plants are evergreen but sometimes the foliage can get battered by late winter.  If this happens, prune off the dead leaves at this time to make room for new growth and flowering.  Some gardeners mow the old foliage off of large plantings of the lenten rose for complete renewal.

The flowers start blooming in mid to late February with rose or cream speckled flowers and bloom for a long time.  The sepals are attractive for a long time after blooming.  Helleborus can reseed heavily by the hundreds under certain conditions.  Usually the seedlings are located at the base of parent plant and can flower in about the third spring.  This can create a nice effect in a natural setting.

Helleborus generally prefer a more moist organic well-draining alkaline soil.  We have them planted in partial to full shade and they have performed excellent.  They will tolerate some drier conditions in the summer.  Plants are long lived and once established, division is seldom.

We have planted many varieties of the Gold Collection® series from Skagit Gardens.  Two that appear outstanding include:  Maestro Hellebore (Helleborus x  ballardiae ‘COSEH890’).  Plant has shiny dark green foliage appearing almost black at times toward the end of the season.  Flower petals emerge a deep pink with white and mature to a creamy white with shades of dusty rose on the backside.  Flowers covered the plant from side to side and was very prolific.  Plants were compact and with good vigor.

Maestro Hellebore in mid-March

Maestro Hellebore in mid-March

Flower fades to a dusty rose color in mid-April 

Merlin Hellebore (Helleborus x ballardiae ‘COSEH810^{USPP #22350}) flowers on this Hellebore emerged with pink color that is brighter than most and then matured to shades of dusty rose.  Blooms were held above foliage creating an impressive display.  Plants were more compact with long lasting dark green foliage and very low maintenance.

Merlin Hellebore with a deep pink color in mid-March

Merlin Hellebore flower color matures to a dusty rose in mid-April

Merlin Hellebore with dense, compact growth habit in mid-April

Hellebores are a great perennial for late winter early spring flower color that are evergreen and low maintenance.  If you do not have some in your garden try some and enjoy the early spring flower color and nice green foliage throughout the rest of the year.