A lover of shady, moist sites, the Lenten rose (Helleborus orientalis) provides blooms when most of the garden is bare, in late winter and early spring. Flower colors range from white, through pink, to light rose-purple, and the cup-shaped blooms appear in clusters on thick stems. The best time for planting Lenten rose is fall, which allows the plant to establish before the growing season begins, but you can also plant in spring. All parts of the Lenten rose are poisonous, and the plant is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9.
Preparing for Planting
The Lenten rose establishes well in organically rich, well-drained soil in partially shaded or bright, full-shade sites, sheltered from cold winds. Soil pH can range from 5.5 to 7.0. Fall planting about two weeks before the average local first frost date is best, but you can also plant Lenten rose after the final local average frost date in spring.
Spread a 4-inch layer of well-aged manure or rich, moist compost over the planting site, and mix the organic matter into the soil to a depth of 12 inches with a garden fork. Wait a week before planting the Lenten rose to allow the soil to settle. After three days, if there's been no rain, and no rain is forecast, water the ground thoroughly to moisten the soil to a depth of 12 inches.
Planting the Lenten Rose
Planting the Lenten rose at the right depth helps prevent crown rots. The crown of a plant is the area where the stems join the roots. Planting Lenten rose so that the crown is covered with soil, and covering the crown with mulches, encourages rotting.
Dig a hole as deep as the root ball of the Lenten rose and 1 1/2 times as wide. Put the plant in the hole, and hold it with one hand so that the plant's crown is level with the surrounding ground. At the same time, scoop the dug soil into the hole with the other hand until the hole is full and the plant stands upright. Gently press the soil around the plant's base with flat hands to firm the root ball in the ground.
Constantly moist soil is key to the Lenten rose growing well. Water a newly planted Lenten rose with a garden hose fitted with a soft spray attachment, directing the water onto the soil at the plant's base, and not the plant stems. When the water begins to puddle, stop watering.
To help the Lenten rose establish quickly, water the plant when the soil surface is dry. Spreading a layer of garden compost 2 inches thick over the soil helps to conserve soil moisture and provide nutrients, but don't allow the compost or other mulches to touch the Lenten rose stems.
Planting Lenten Rose Hybrids
Lenten rose hybrids grow best in similar conditions to the Lenten rose. Lenten rose "Millet Hybrids" (Helleborus orientalis "Millet Hybrids," USDA zones 4 through 9), prefers alkaline soil and moderate or light shade. Growing 12 to 18 inches tall and 18 to 24 inches wide, "Millet Hybrids" features rose, light pink or white flowers. Lenten rose Early Purple Group (Helleborus orientalis subsp. abchasicus Early Purple Group, USDA zones 5 through 9) is a hybrid that grows best in the same conditions as its Lenten rose parent. This hybrid grows 9 to 15 inches tall, and bears plum-purple flowers with yellow stamens.