Winter-blooming hellebores have extensive, woody root systems that enable them to thrive and bloom in freezing temperatures.

The earliest blooming hellebores (Heleborus foetitus) in the Lehigh Valley can bloom as early as December and may continue into April. In a cool spring, some species will continue blooming into May, by which time they will set seed and stop producing flowers.

There are about 20 species of hellebores. However, the ones you are most likely to find in area nurseries are Pimex, Holod’s and Robertsons. At the national chain retailers are H. niger, H. orientalis and H. x hybridus. Other varieties can be purchased at specialty nurseries.

H. niger, commonly called the Christmas Rose, gets its name from its black root. It has leathery green or blue-green leaves, depending on the species, and produces white flowers. It does not bloom at Christmas in our climate. It typically blooms in late January or February depending on the weather. It is evergreen and grows to about 12-inches-tall.

H. orientalis, commonly called the Lenten Rose, is a slow growing plant that dislikes being disturbed and is slow to recover when moved. Its blooms are pink purple, white or near white. It will naturalize under the right conditions and the evergreen foliage makes it a good groundcover once established. It typically blooms in the region in March and grows to 16- to 20-inches-tall.

H. x hybridus hellebores are vigorous cross-pollinators. This vigorous cross-pollination produces the hybrids, which comprise the biggest group of hellebores you’re likely to find. The hybrids are larger, more vigorous plants and produce some of the most interesting and beautiful flowers.

Hellebores grow well in almost all types of soil and in almost all types of garden conditions. They perform reliably in Zones 4 through 7 and are untouched by rabbits or deer.

Like hostas, they are commonly sold as shade plants because they will grow and flower in shade. However, they will grow and flower better in a bit of sun.

They are not fussy except in that they cannot tolerate wet feet, especially not in winter. They like water but they require good drainage. They need a bed deep enough for their extensive roots to run and they prefer a soil with high organic content.

When planting, add compost to the planting hole and backfill with a mixture of one-half removed soil and one-half organic matter.

Mulch with compost in the spring. Good soil compost is all the fertilizer they’re going to need.

If your soil is not in good condition, fertilize them immediately after the flowering season (May-July) with a good, slow-release fertilizer, then start to mulch with compost every spring.

Allow 12 inches to 2 1/2 feet between plants. Some of them, particularly the hybrids, mature into big plants. Spacing information should be on the plant tag.

Spring is the season you are most likely to find hellebores in the stores. Look for these heavenly hellebores, one of the underused garden superstars.

“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.