Leucojum

( lew- KOH - jum )

At-A-Glance Information

Commonly called Snowflake, St. Agnes Flower, or Snowbells, these delicate bell-shaped flowers are beautiful early springtime bloomers. They need full sun in spring and prefer light shade otherwise, making them perfect for growing underneath deciduous shrubs and trees. They need regular waterings during their growth and blooming periods. Use these bulbs in the landscape for mass-planting as a groundcover, to naturalize open woodland borders, or as an early-season food source for pollinators. Take care when planting Leucojum in the landscape, as all plant parts are toxic to humans and pets if ingested.

Leucojum Species and Varietals

Leucanthemum is a member of the family Amaryllidaceae, and includes just two species. Former species in this genus have been moved to Acia, and the genus is also closely related to Galanthus and Narcissus. The best growing zones for Snowflake vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Leucojum aestivum (Summer Snowflake, Giant Snowflake, Loddon Lily, Dewdrop, Snowbell)
This flower is best in USDA hardiness zones 4-9 or Sunset growing zones 1-10 and 14-24. Stems reach a foot and a half tall and each carries 3-5 flowers They bloom in midspring and summer, though in mild-winter areas, these plants can flower from late fall through wintertime as well. Cultivars include 'Gravetye Giant' (pictured, taller and with 9 large flowers per stem), and 'Nancy Lindsay' (to 20-24 in. tall with 5-6 flowers per stem). This species is considered invasive in the East Coast, Mid-Atlantic, and Midwestern regions of the United States.

Leucojum vernum (Spring Snowflake, St. Agnes' Flower, Snowbell, Dewdrop, Common Bulbous Violet)
This species is native to central and southern Europe and grows well in USDA hardiness zones 4-9. Flowers are present in springtime. These plants will form clumping colonies over time, and each plant bears a single white flower with greenish marks towards petal tips. Flowering stems reach up to 8 inches tall on average. This species is considered invasive or aggressively weedy in the Mid-Atlantic and New England regions of the United States, Japan, and the Netherlands. Cultivars are listed and described below:

'Eva Habermeier'
To 6-12 inches tall with yellow apical marks.

'Golden Bell'
With yellow ovaries and bold yellow markings on petals. 5-14 inches tall.

'Green Lantern'
With prominent green markings on tepals.

'Hoch die Tassen'
To 8 to 12 inches tall, with Upward-facing flowers.

'Janus'
Blooms in early January, reaching 8-12 in. tall.

'Null Punkte'
Pure white flowers. To 6-10 inches tall.

'Podpolozje'
To 6-16 inches tall, robust with yellow spots.

'Gertrude Wister'
Semi-double flowers on a 4-10 inch tall plant.

Caring for Leucojum

Leucojum bulbs are typically planted in fall, planted with their pointed end upwards. They can be planted in a hole that is about 2-3 inches deep, and then covered with soil. Space bulbs about 2-4 inches apart for best coverage and airflow. They will overwinter under the soil surface, and bloom in springtime. These plants prefer to be situated in soil that is well-draining, moderately fertile, and that has a pH of between 5.5 and 7.0. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Mulch around the base of plants to increase soil moisture retention, suppress weed growth, and maintain consistent soil temperatures.

Water newly planted Leucojum bulbs regularly to help them develop strong root systems. At maturity, these flowers can tolerate drought during their summer dormancy, but prefer consistent moisture during their active growing and blooming seasons in late winter and early springtime. As a general rule of thumb, irrigate whenever the top inch or two of soil feels dry to the touch, and withhold most waterings in summertime. Foliage will die back before summer heat sets in, and once it has completely died, it can be removed from the plant. Flowers can be deadheaded to discourage re-seeding unless you will be harvesting seeds for propagation. If grown in a cramped space or container, Leucojum will need to be divided every four to five years. For information on how to divide Snowflakes, see the Propagation section below.

Propagation

Leucojum, or Snowflake, is best propagated via division of existing plant clumps. These plants grow from bulbous root systems, which can easily be dug up, divided and replanted elsewhere. To propagate your Snowflake, follow the directions below.

Propagating Leucojum by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one bulb attached.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.

Problems and Pests

Certain species of Leucojum are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Leucojum, or Snowdrop, plants are typically resistant to pests and diseases in the landscape.