Yucca filamentosa (YUK-uh fil-uh-men-TOH-suh) is a flowering, evergreen shrub from the family Asparagaceae.
It hails from the Southeastern United States and is popular thanks to its unique shape and sword-like leaves.
The plant is easy to grow with basic care needs. It grows indoors and outdoors, depending on how large you want the plant to grow.
Filamentosa goes by several common names:
- Adam’s Needle
- Common Yucca
- Spanish Bayonet
- Needle Palm
- Silk Grass
- Bear Grass
- Spoon Leaf Yucca
- Spanish Dagger
There are a number of types of yucca plants in the genus including:
- Yucca elata
- Yucca gluaca
- Yucca flaccida
- Yucca brevifolia
Caring For Yucca Filamentosa
Size & Growth
Adam’s Needle are tough plants with a slow growth rate, but it is not a small plant. It can grow to 10’ feet tall when fully mature with leaves that spawn about 2.5’ feet long. The plant spreads about 2’ to 3’ wide.
The bulk of this plant’s height comes from the flower stalk growing from the middle of the plant, giving it a much taller appearance.
This is also where the flowers will bloom during the summer season.
Despite its native home in Southeastern U.S.A, Adam’s Needle grows in USDA hardiness zones 5 to 10.
Flowering and Fragrance
Yucca Filamentosa has a unique appearance. The foliage is characterized by bluish-green leaves that grow to be 2’ to 3’ tall.
The base of the plant has a rosette of sharp, sword-shaped leaves that are 30” long and can spread to 4” wide appearing in late spring.
This plant can take a long time to bloom during its first attempt, sometimes going up to three years without a bloom.
However, when it does, it usually occurs during the summer months through the fall.
The creamy white yucca flowers are in the shape of drooping white bells or bulbs with a soapy fragrance.
Light & Temperature
Adam’s Needle tolerates full sun but also does well in areas partial shade.
If planting indoors, a west facing window is best as too much sun exposure such as in a south facing might dry it out.
It bodes best in temperatures ranging from 65 – 75 degrees Fahrenheit.
This plant is resistant to cold temperatures and frost and can survive in temperatures as low as 5 degrees Fahrenheit.
Watering and Feeding
The plant is drought tolerant, but it still requires some level of moisture. Water the plant more often during the growing season but reduce the frequency as winter approaches.
During the spring, and summer seasons water up to twice a week. Make sure the roots aren’t drowning and gradually reduce to once a month in the colder months.
Feed once every two weeks during the summer months with a good quality water-soluble fertilizer. The plant needs no feeding during the fall or winter.
Soil & Transplanting
Adam’s Needle requires a well-drained soil that ideally has a pH from 5.5 to 7.5. However, it can flourish in poor, sandy soils.
Transplant Adam’s Needle every three or four years into a larger pot in the winter months. The pot should contain a mixture of sand, garden soil, and top soil.
Grooming and Maintenance
If the weather veers on the drier side, spray the plant with water to keep it looking fresh. Keep your plant looking its best by tearing off yellowing leaves after they have dried.
Light pruning and remove branching from the trunks during the months from February to May.
However, be careful not to remove all the leaves. Leave a minimum of three leaves on each branch, or else it will become difficult for the leaves to grow back.
When handling this plant, take care to wear gloves for protection from the sharp leaves that can leave deep cuts.
Propagating Needle Yucca
Propagate Adam’s Needle by seed or stem cuttings. Remove one or several stems between 5” to 10” inches long.
Allow the cut to dry over before you plant yucca in its new home, which should be with a fibrous sandy soil.
The stems should be kept moist and placed in a shaded location until roots begin to develop. This can take one to two months.
Needle Palm Pest or Disease Problems
Too much moisture can cause rust fungus in this plant. This usually occurs during winter. Prevent this by protecting the plants from heavy winter moisture.
The plant also needs insecticide regularly to keep slugs and snails at bay as these can damage the plant.
Adam’s Needle is also prone to mites. This is characterized by speckling on the leaves or the appearance of gray webs.
This can be prevented with miticides, pruning, and soaping with special insecticidal soap.
Fungal diseases can occur in the form of spotted leaves with reddish-orange marks. These should be removed as soon as possible to prevent the disease from spreading to other leaves.
Using The Adam’s Needle
This plant is excellent as an indoor houseplant or as part of yuccas in the outdoor garden or rock garden.
It grows in areas with otherwise poor soil or too much sun and can help control soil erosion. The interesting appearance makes it a perfect addition to add some contrast to your plants.