Common Name Star of Bethlehem, grass lily, nap-at-noon
Botanical Name Ornithogalum umbellatum
Family Asparagaceae
Plant Type Perennial, bulb
Mature Size 4-6 in. tall, 2–3 in. wide
Sun Exposure Full, partial
Soil Type Well-drained
Soil pH Acidic, neutral, alkaline
Bloom Time Spring
Flower Color White
Hardiness Zones 4–9 (USDA)
Native Area Europe, Africa
Toxicity Toxic to people, pets

Star of Bethlehem Care

In proper conditions, star of Bethlehem bulbs grow quickly. Here are the main care requirements for star of Bethlehem:

  • Choose a spot that gets at least six hours a day of sunlight; these bulbs can grow with less sun but will not flower as spectacularly.
  • Plant in soil that is well-draining, as these bulbs will rot if left in water.
  • When the plant is growing, water if the soil becomes particularly dry; do not water during dormancy.
  • Amend the soil with compost or slow-release fertilizer at the beginning of each spring.

Warning

Star of Bethlehem readily escapes gardens and has naturalized in many regions of North America. Its bulbs multiply rapidly, and the flowers also readily self-seed. In many states, this foreign plant earns a severe “Do Not Plant” warning against invasiveness. Check with local experts before inviting this plant into your garden.

Light

Although it can grow in partial shade, Star of Bethlehem prefers a spot with full sun, meaning at least six hours of direct sunlight on most days. Its flowering will be better in full sun.

Soil

Star of Bethlehem likes loamy soil. Sharp soil drainage is key for healthy growth. In waterlogged soil, the bulbs can rot.

Water

Young star of Bethlehem plants need regular watering to keep the soil evenly moist but not soggy. Mature plants have some tolerance for dry soil, but they still prefer a moderate amount of moisture. While the plant is actively growing in the spring and summer, water when the soil feels dry a couple inches down. When the plant is dormant, its moisture needs are diminished, and it typically doesn’t need any supplemental watering. Stop watering when the foliage begins to turn yellow after the flowers are spent.

Temperature and Humidity

Star of Bethlehem is quite hardy to the temperature extremes of its growing zones (4 to 9). Humidity also typically isn’t an issue, as long as its soil moisture needs are met.

Fertilizer

Star of Bethlehem flowers best when grown in rich soil. Mix some compost into the soil each spring to promote healthy growth. Additional fertilizing is not necessary, and may even hinder flowering.

Types of Ornithogalum

Star of Bethlehem does not have any named cultivars, but the Ornithogalum genus contains 200 other species similar to Star of Bethlehem flower. They include:

  • O. arabicum: This plant bears white flowers and grows to around 19 inches tall. It’s hardy in zones 9 to 10.
  • O. dubium: This species features orange flowers and reaches only around 10 inches tall. It grows in zones 7 to 10.
  • O. nutans: This species grows to around 16 inches high and has white flowers with a lot of green in them. It grows in zones 6 to 10.
  • O. thyrsoides: This species also has white flowers and grows to around 16 inches tall. It’s hardy in zones 7 to 10.

Pruning

After star of Bethlehem flowers finish blooming, you will be left with a mass of tangled foliage that isn’t particularly attractive. However, resist the urge to remove that foliage. As long as it stays green, it will be feeding the bulbs through photosynthesis.

Ultimately the leaves will turn brown and the plants will go dormant in the summertime, leaving gaps in your garden bed, at which time the foliage can be removed. Many gardeners opt to plug those gaps with annual plants, while others grow perennials next to their star of Bethlehem plants that will fill in the space as summer progresses.

Propagating Star of Bethlehem

The bulbs will multiply prolifically over time, producing what are referred to as offsets or bulbils. Here’s how to propagate the plant:

  1. In late summer as the foliage is dying back, use a shovel or trowel to dig up the bulbs.
  2. Carefully separate the offset bulbils clinging to the parent bulb.
  3. Immediately replant the bulbils and parent bulbs about 3-6 inches deep and 4 inches apart in moist, loamy soil. The smallest bulbils may require a full two years before they are mature enough to bloom.

Overwintering

Within its hardiness range (zones 4 to 9), star of Bethlehem is a sturdy plant that rarely succumbs to winter cold. However, gardeners in the northern part of zone 4 may want to protect plants in exposed locations with a layer of dry mulch over the winter. Avoid letting the bulbs soak in cold wet ground, as this can encourage bulb rot. The bulbs can also be dug up and stored in a protected space, such as a basement, in extremely cold areas.

How to Get Star of Bethlehem to Bloom

Star of Bethlehem plants flower readily, offering 10 to 20 starry white flowers on each stem. The flowers generally open about noon, then close at sunset or when the skies are cloudy.

Bloom Months

Star of Bethlehem normally produces an impressive flush of white flowers for several weeks in May and June.

What Do Star of Bethlehem Flowers Look and Smell Like?

The flowers of star of Bethlehem plants are small, white, and star-shaped, standing out among the dark foliage. They offer a lightly sweet fragrance.

How to Encourage More Blooms

Poor flowering can result if the plant is not getting enough sunlight, if it is overfed with nitrogen-rich fertilizer, or if the bulbs are not yet mature enough.

Propagating offsets may require two years before they flower, and plants started from seeds can take even longer. Patience may be all that is required.

Caring for Star of Bethlehem After It Blooms

After blooming, leave the foliage of this plant alone, watering occasionally only if the soil gets quite dry, until the foliage turns brown, indicating dormancy. At this time, it’s safe to prune the bulbs or plant annuals in their space.

Deadheading Star of Bethlehem Flowers

While deadheading the spent flowers does not prompt additional blooming, it does limit the spread of the plant by eliminating the seeds that readily volunteer wherever they fall in the garden.

Common Problems With Star of Bethlehem

The only significant problem with this plant is its eagerness to spread aggressively. Take care when planting it in a mixed garden bed, as it can take over the space and displace other garden plants. This plant is best used as an underplanting around rose bushes or sturdy shrubs, or in confined meadowy areas where there is no chance of its spread elsewhere.

Eliminating a colony takes some diligence, requiring that you carefully dig up the bulbs as you notice plants emerging in the spring. Because Star of Bethlehem also self-seeds so easily, you’ll also need to keep an eye out for tiny volunteers that can fuel a resurgence of a troublesome colony.

FAQ

    • A folktale talks of fragments of the biblical star of Bethlehem falling from the sky and taking root as Ornithogalum plants. Several other common names derive from the plant’s habit of opening at midday and closing in cloudy or dark conditions.

    • Do so carefully. star of Bethlehem is a vigorous plant that is eager to spread and naturalize outside the confines of the garden. In meadows and woodlands, it will quickly establish colonies. In the confines of the garden, it is best used for underplanting beneath roses and shrubs, where its spread can be supervised.

    • Try Allium neapolitanum (daffodil garlic), a form of false onion with similar flowers. It is hardy in zones 7 to 9. Other species in the Allium genus are also available for colder regions. Alliums are much easier to control than star of Bethlehem.