Nerine lilies, often called Guernsey lilies, bloom in autumn or early winter, unlike most garden plants. This unique cycle means their winter care differs significantly from other garden plants. Proper winter management is important for ensuring their continued health and a spectacular display year after year.
Hardy and Tender Nerine Varieties
Identifying the specific type of Nerine lily in your garden is the first step in providing appropriate winter care, as their cold tolerance varies greatly. Hardy varieties, most commonly Nerine bowdenii, can often remain in the ground through milder winters. These plants are characterized by their strap-like, green foliage that often appears before or alongside their pink, trumpet-shaped flowers.
Conversely, tender varieties, such as Nerine sarniensis with its often larger, more intensely colored blooms, are sensitive to frost and prolonged cold. Their foliage often emerges after flowering and is less robust in freezing conditions. Recognizing these differences allows gardeners to select the best winter protection strategy for their specific plants.
Preparing Nerines for Winter
As temperatures consistently drop, preparing Nerine lilies for winter becomes necessary. For all Nerine types, gradually reduce watering as the plants approach dormancy, typically by late autumn. This reduction helps signal to the bulb that it is time to rest and prevents issues like rot in cold, damp soil.
Hardy Nerine bowdenii varieties benefit from a protective layer of organic mulch, such as straw or shredded leaves, applied over the bulb area once the ground begins to cool. This insulation helps regulate soil temperature and provides a buffer against sudden hard freezes. Allow the foliage to naturally die back and yellow before any removal, as the leaves continue to photosynthesize and store energy in the bulb.
Tender Nerine varieties require more active preparation. Once their foliage begins to yellow or after the first light frost, cease all watering. This encourages the bulb to enter a dry, dormant state, which is crucial for successful overwintering.
Winter Care for Nerines
Winter care for Nerine lilies depends directly on whether they are hardy or tender varieties and the severity of your local climate. For hardy Nerine bowdenii left in the ground, the primary focus is on ensuring good drainage around the bulbs throughout winter. Excess moisture combined with cold temperatures can lead to bulb rot.
Maintain the layer of mulch over hardy Nerines to provide consistent insulation, reapplying if necessary after strong winds or heavy precipitation. During their dormancy, these outdoor plants require no additional watering, relying on natural rainfall. Their bulbs withstand freezing temperatures when adequately protected and dry.
Tender Nerine sarniensis bulbs, particularly in areas where temperatures drop below approximately -4 degrees Celsius, typically need lifting from the ground before a hard freeze. Carefully dig up the bulbs, allowing excess soil to dry and fall away, but avoid washing them. Store lifted bulbs in a cool, dark, dry location, such as a garage or shed, at a temperature range of 4 to 10 degrees Celsius.
Potted tender Nerines can be moved indoors before freezing temperatures. Place them in a cool, bright location where temperatures remain above freezing but below typical room temperature, ideally between 7 and 13 degrees Celsius. Reduce watering significantly, providing just enough moisture to prevent the potting mix from completely drying out. Keep the bulbs dormant or semi-dormant until spring.
Post-Winter and Spring Revival
As winter recedes and spring emerges, prepare Nerine lilies for their next growth cycle. For hardy Nerine bowdenii left in the ground, gradually remove the winter mulch layer as the threat of hard frosts passes. This allows the soil to warm more quickly, encouraging new growth.
For lifted and stored tender Nerines, begin revival in early spring, typically around March or April, or once outdoor temperatures consistently stay above 10 degrees Celsius. Replant bulbs in fresh, well-draining potting mix or directly into prepared garden beds. Plant them at a depth where the neck of the bulb is just at or slightly above the soil surface.
Start watering sparingly after planting, increasing frequency as new growth becomes visible. A light application of a balanced, slow-release granular fertilizer can provide nutrients for the emerging foliage and roots.
For potted tender Nerines brought indoors, gradually increase watering and move them to a brighter, warmer location to encourage active growth before transitioning them back outdoors after all danger of frost has passed.