Adam's needle

Sun

Full sun is best. Tolerates light shade, but flowering and leaf stiffness may be reduced.

Water

Water regularly during establishment, allowing the soil to dry between waterings. Established plants usually need water only during prolonged drought; avoid persistently wet winter soil.

Soil

Well-drained sandy, gravelly or loamy soil, from acidic to alkaline. Tolerates poor soil but struggles in waterlogged clay.

Height

Foliage 2-3 ft (0.6-0.9 m); flower stalks 5-8 ft (1.5-2.4 m)

Spread

3-5 ft (0.9-1.5 m), eventually wider through offsets

Flowers

Late spring to midsummer, depending on climate; branching spikes of hanging, creamy-white, bell-shaped flowers. Young or shaded plants may take several years to flower.

Foliage

Evergreen rosettes of rigid, sword-shaped green to blue-green leaves with sharp tips and curling white threads along the margins.

Growth

Slow to moderate; established clumps gradually widen by producing offsets.

Care needed

Low

• Plant with the crown at soil level and keep it clear of soil and mulch.
• Water new plants deeply when the soil dries; reduce watering once roots are established.
• Do not feed routinely. In very poor soil, apply a light dose of balanced fertiliser in spring.
• Use a thin gravel mulch rather than moisture-holding organic mulch around the crown.
• Remove unwanted offsets while small to limit the clump's spread.
• Wear gloves and eye protection when working among the pointed leaves.

Pruning. Cut spent flower stalks close to their base after flowering. In spring, remove dead or badly damaged outer leaves individually without cutting into the central growing point.

Spring

Remove winter-damaged leaves and check that soil or mulch has not buried the crown.

Spring

Plant or transplant into freely draining soil; separate rooted offsets if needed.

Late spring

Check new plants for dry soil and water deeply when necessary.

Summer

Remove spent flower stalks once flowering finishes.

Autumn

Remove unwanted offsets and clear fallen leaves from the crown.

Winter

Keep drainage outlets clear and avoid watering unless container soil is dry and unfrozen.

• Use as a sculptural focal point in gravel gardens with low sedums and ornamental grasses.
• Repeat clumps along a sunny border to give structure among softer flowering perennials.
• Plant in a raised, well-drained bed beside paving or masonry, keeping sharp leaves well back from walking routes.
• Combine with lavender and catmint in dry, sunny borders for contrasting leaf shapes and flower colour.

Garden styles it suits: Architectural minimal, Dry gravel garden, Desert / xeriscape, Modern Mediterranean, Coastal and Low-maintenance.

Plant it with: Lavender, Catmint, Russian sage, Butterfly weed, Little bluestem and Stonecrop.

Wildlife: In its native eastern North American range, specialist yucca moths pollinate the flowers and lay eggs whose larvae eat some developing seeds. Seed production outside that range is often limited by the absence of the appropriate moths.

• Crown or root rot in wet soil: improve drainage or move to a raised bed; discard plants with a soft, rotten crown.
• Fungal leaf spots in humid conditions: remove badly affected leaves, improve airflow and avoid overhead watering.
• Scale insects: inspect leaf bases and undersides; remove small infestations by hand or use a labelled horticultural oil.
• Persistent unwanted shoots: dig out offsets with their attached roots; remaining root fragments can regrow and may need repeated removal.

Toxic to cats, dogs and horses if eaten: yuccas contain saponins, and ingestion can cause drooling, vomiting or diarrhoea. Keep all plant parts out of reach of grazing animals and pets. Raw plant material can also cause digestive upset in people; do not treat it as an edible plant. The sharp leaf tips can injure skin and eyes.

Where it spreads. Can form persistent, spreading colonies in gardens in the United States, Canada, the UK and Australia through offsets and root fragments. This local garden spread does not necessarily mean it is officially listed as invasive; avoid planting where escape into nearby sandy or coastal habitat would be difficult to control.

• Weak-leaf yucca (Yucca flaccida)

  Usually has thinner, more flexible leaves that bend or droop toward their tips. The two species are very similar, and nursery names are often mixed.

• Spanish dagger (Yucca gloriosa)

  Usually develops a visible woody trunk and has broader, stiffer leaves with few or no curling marginal threads.

• Century plant (Agave americana)

  Has much thicker, fleshy leaves with conspicuous teeth along the edges rather than fine curling threads.

The species name filamentosa means thread-bearing, referring to the curling fibres along the leaf edges, while Adam's needle refers to the sharp, needle-like leaf tips.

Propagation. Separate rooted offsets in spring and replant at their original depth. Root cuttings also grow readily. Seed is possible where suitable pollination occurs, but seedlings are slow to reach flowering size and named cultivars may not come true.

Accepted botanical name

Yucca filamentosa

In the US and Canada

Native in the lower 48 states.

Native range

Alabama, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia and West Virginia.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.