Yucca filamentosa
Adam’s needle is a striking and stately ornamental succulent, with long, sword-like foliage and bold flower stalks topped with showy panicles of creamy, bell-shaped flowers.
These handsome plants are often grown as specimens in succulent beds, foundation plantings, islands, and planters.
They also produce offsets regularly, forming attractive clumps that can be used as low barriers, borders, and hedges.
We link to vendors to help you find relevant products. If you buy from one of our links, we may earn a commission.
A native of the southeastern United States and Mexico, these robust specimens are highly drought resistant and require little upkeep, thriving in lean soils and dry conditions.
They have good cold hardiness too and are quite comfortable with winter temperatures in USDA Hardiness Zone 4.
Adam’s needle is the perfect “hands-off” plant for gravel or sandy areas, rockeries, and any xeriscape setting.
The lovely, lantern-like flowers last for weeks and attract hummingbirds and moths but are left alone by deer and rabbits.
Are you ready for a low maintenance, water-wise ornamental with a big impact? Then let’s discuss how to grow Adam’s needle yucca!
Here’s what you’ll find ahead:
What Is Adam’s Needle?
Adam’s needle yucca (Yucca filamentosa) is a species of flowering plants in the Asparagaceae family that are native to the southeastern United States and Mexico.
In its original habitat, Y. filamentosa grows in dry, sandy or rocky soils on bluffs, coastal regions, woodland fringes, and open prairies and is highly drought tolerant.
A broadleaf evergreen succulent, the leathery, sword-shaped foliage radiates from a basal rosette and bears fine, thread-like filaments along the edges with a sharp, spiny tip.
In late spring, plants produce tall flower stalks with clusters of nodding, lantern-like flowers in creamy white, blooming for several weeks.
After flowering, pods form, containing small black seeds that are most often dispersed by wind.
Growth is moderate with a mature height of two to three feet tall and spread of three to four feet wide, and plants produce offsets annually, developing into attractive clusters.
Y. filamentosa has good resistance to heat and cold and the plants are suitable for cultivation in USDA Hardiness Zones 4 to 10.
It should be noted that the plant’s roots contain saponins which are toxic to cats, dogs, and horses.
Cultivation and History
Historically, Adam’s needle, also called Spanish bayonet or Carolina silk grass, was used extensively by Native Americans for food, medicine, toiletries, and the strong fibers for cordage and weaving.
By 1675 it was being cultivated as an ornamental by colonists and was reportedly grown in the gardens of George Washington and Thomas Jefferson.
Sir Walter Raleigh introduced it to Europe via Great Britain on one of his return trips from North America.
The species name filamentosa refers to the foliage’s tough, filament-like fibers and the common name refers to the sharp needle-like tips on the ends of the leaves.
Adam’s Needle Propagation
Adam’s needle can be propagated from cuttings, by seed, and via offsets.
Sowing seeds requires quite a bit of patience as plants propagated this way can take up to five years to flower.
Cuttings can be taken from mature specimens in spring and summer and propagated either in soil or water.
Our guide to propagating yucca has all the details, and if you’ve got a mature plant that is putting out pup, check out our article about transplanting offsets.
The easiest way to get started with Adam’s needle, is to purchase a plant from the nursery and transplant it into your garden.
Read our guide to growing yucca for more information.
How to Grow Adam’s Needle
Adam’s needle succulents do best when planted in sandy or gravelly soil with average fertility, a slightly acidic pH of 5.5 to 6.5, and a full sun exposure.
When planting, loosen the soil to a depth of 12 to 18 inches and create a hole twice as wide and slightly deeper than the root ball.
To one part of soil, mix in one part of organic materials such as compost, well-rotted manure, or worm castings is sufficient for their nutritional needs.
To improve drainage, add in one or two parts of grit, such as landscape sand, pea gravel, or stone chips. Excellent drainage is crucial for the health of Adam’s needle as wet or overly moist soil can lead to problems like crown and root rot.
If you live in areas with high rainfall, you can situate the plants on a slope or in raised mounds to improve drainage.
Set plants in place at the same depth as in their nursery pot, with the crown just below the soil line.
Backfill with soil and firm in place. Water gently and deeply to settle.
Allow two to three feet of space between specimens.
Like most succulents, Y. filamentosa requires minimal moisture and overwatering should be avoided to keep the roots and crown healthy.
Allow the soil to dry out to a depth of three to four inches between waterings, then give your plants a long, deep drink to ensure the extensive tap root receives sufficient moisture.
For container growth, ensure your pots and planters have adequate drainage holes to prevent soggy soil.
I like to add a layer of porous materials like broken pottery or pebbles to the bottom of pots to ensure water moves freely.
Use a porous, gritty soil that provides good drainage – our recipe for succulent potting soil is ideal.
Allow the soil to dry thoroughly between water applications.
If desired, you can apply a two-inch layer of gravel mulch to keep the roots cool and slow down water evaporation.
Avoid using organic materials for mulching – they hold onto too much water which can lead to crown rot.
Learn more about growing yuccas in containers in our guide.
Growing Tips
- Plant in well-draining soil to avoid issues like root rot.
- Y. filamentosa can tolerate some light afternoon shade but flowers best in full sun.
- Water when the top two to three inches of soil is dry.
Pruning and Maintenance
These easy going plants require little maintenance, but a spring cleanup helps to improve their appearance and address any frost damage.
In early spring, use clean sharp shears to remove any brown, damaged, or dead leaves, cutting them close to the main stem.
Lower, downward-facing leaves can also be removed at this time if you prefer a clean stem over the skirted look.
Read our guide to pruning yucca to learn more.
After flowering, if you don’t want to collect seeds for propagation, remove the flower stalk by cutting it close to the base.
For seed collection, allow the pods to mature and ripen over summer.
Once the pods have dried and turned beige or light brown, remove them from the stem and crack open the pods to reveal the seeds.
Seeds can be stored in dry sand in a cool, dark, and dry environment for up to five years.
Adam’s needle plants are moderate feeders and can be fertilized in spring by working in two inches of compost as a side dressing over the root zone, taking care to keep it a few inches away from the base of the plant.
Or you can apply a balanced, all-purpose, slow release fertilizer or a product formulated for cacti and succulents.
Down to Earth Cactus and Succulent Fertilizer
Down to Earth Cactus and Succulent Fertilizer has a NPK ratio of 2-4-8 and is available in one- and five-pound boxes at Arbico Organics.
Adam’s Needle Cultivars to Select
There aren’t a large variety of cultivars to choose from, but the species plant offers durable beauty for the water-wise garden.
Adam’s Needle
The standard bearer of Y. filamentosa, Adam’s needle plants in two- or three-gallon pots can be purchased at Nature Hills Nursery.
For a pop of bright color, ‘Color Guard’ is a beautiful variegated variety with bright yellow leaves edged in olive green.
‘Color Guard’
Potted specimens are available at Perfect Plants Nursery and Plants By Mail.
There are a couple of others including ‘Gold Sword’ that is similar to ‘Color Guard’ but features streaks of green and gold on the foliage.
Managing Pests and Disease
Adam’s needle typically experiences few problems with pests and diseases, but there are a couple of issues to watch for.
Aphids are common sapsuckers that can be found feeding on leaves or flower stalks.
A strong spray of water from the garden hose is usually enough to dispatch these bugs but may need to be repeated for a few days to completely destroy the colony.
Black spots on the leaves may be a sign of a fungal infection that’s typically spread by spores being splashed onto the leaves by water.
Remove infected leaves with clean, sharp shears and avoid overhead watering.
A natural fungicide and insecticide like neem oil can be used for persistent fungal infections.
Bonide Neem Oil
You can find neem oil available at Arbico Organics.
Best Uses for Adam’s Needle Yucca
With its striking profile, Adam’s needle yucca makes a handsome specimen plant or focal point in mixed succulent beds, containers, city and courtyard gardens, foundations, and islands.
And its drought tolerance makes it ideal for Southwestern or Mediterranean themed gardens as well as in gravel beds, rockeries and sandy swaths or any water-wise setting or xeriscape.
Quick Reference Growing Guide
| Plant Type: | Perennial succulent | Flower/Foliage Color: | Creamy white/green, variegated |
| Native to: | Southeastern US and Mexico | Maintenance: | Low |
| Hardiness (USDA Zone): | 4-10 | Tolerance: | Deer, drought, rabbits, rocky soil |
| Bloom Time/Season: | Late spring/early summer | Soil Type: | Sandy, gravelly |
| Exposure: | Full sun | Soil pH: | 5.5-6.5 |
| Time to Maturity: | 3-5 years (flowers) | Soil Drainage: | Well-draining |
| Planting Depth: | Just below soil surface (seeds), root ball depth (transplants) | Attracts: | Butterflies, moths, hummingbirds |
| Spacing: | 2-3 feet | Uses: | Mixed beds, containers, foundations, islands, rockeries, theme gardens |
| Height: | 2-3 feet | Order: | Asparagales |
| Spread: | 3-4 feet | Family: | Asparagaceae |
| Water Needs: | Low | Genus: | Yucca |
| Common Pests and Diseases: | Aphids; leaf spot | Species: | Filamentosa |
Showy Succulents
With their bristling silhouette of sword-like foliage and dramatic, long-lasting flower spikes, Adam’s needle yuccas are showy succulents with a tough nature!
Y. filamentosa adds a bold, prominent presence as a specimen in city and courtyard gardens, foundations, islands, and mixed succulent beds; and make handsome groupings arranged into borders or rows.
Wonderfully low maintenance, they thrive in arid conditions making them a sound choice in water-wise settings like gravel beds, sandy soils, rockeries, Mediterranean and Southwestern gardens, or any xeriscape environment.
Water occasionally, feed once a year, and give them sun – then sit back and enjoy how these succulent showpieces strut their stuff!
Are you growing Adam’s needle yuccas? Let us know in the comments section below!
And if you’d like to learn more about growing yucca plants, add these guides to your reading list next:
