When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.
Adam’s needle yucca (Yucca filamentosa) is a plant in the agave family that is native to the Southeastern United States. It was an important plant to Native Americans who used its fibers for cord and cloth, and the roots as a shampoo.
Today, the plant is used primarily as an ornamental in the garden. Continue reading for more Adam’s needle information, as well as tips on growing Adam’s needle yucca plants.
Adam’s needle plants are hardy in zones 4-10. They grow 3-4 feet (.91-1.2 m.) tall and wide. The common name Adam’s needle is derived from the plant’s long, sword-like foliage with sharp needle-like tips. These straps of foliage bear tiny thread-like filaments around their edges, which appear as if the plant is peeling.
In late spring, Adam’s needle yucca forms tall stalks from which 2-inch (5 cm.), bell shaped, white flowers hang. Because of these unique lantern-like flower stalks, Adam’s needle yucca is often used in the landscape as a specimen plant. The flowers last for several weeks.
The yucca flowers are only pollinated by the yucca moth. In a mutually beneficial relationship, the female yucca moth visits yucca flowers at night and collects pollen in specialized parts of her mouth. Once she has collected the necessary pollen, she lays her eggs near the ovary of the yucca flower then covers the eggs with the pollen she has collected, thereby fertilizing the plants egg. In this symbiotic relationship, the yucca gets pollinated and the yucca moth caterpillars use the yucca flowers as a host plant.
As an avid gardener I’m always seeking out unique specimen plants to diversify my landscape. The architectural Adams Needle plant also known by its botanical name Yucca filamentosa, first captured my attention years ago. I was mesmerized by its bold rosette of sword-shaped leaves and towering flower stalks. However, my early attempts to add Adams Needle to my garden met with failure, and I eventually realized I had been planting them at the incorrect depth.
Through trial and error I learned the proper planting depth is critical to the health and performance of Adams Needle plants. Plant too shallow and the roots are exposed. Bury too deep, and rot quickly sets in. In this article, I’ll share everything I wish I’d known from the start about how deep to plant Adams Needle plants for optimal growth and survival.
Adams Needle Plants Love Well-Draining Soil
Native to arid regions of the southern United States, Adams Needle plants are adapted to hot, dry environments. Although adaptable to various soil types, these tough plants thrive best in sandy, fast-draining soils. Heavier clay soils must be amended with gravel, perlite or sand to provide sufficient drainage. Compacted or dense soils prevent adequate air circulation to the roots. Proper soil preparation is key before planting your Adams Needle.
Pick the Right Planting Site
Carefully choose an appropriate location before beginning the planting process. Adams Needle thrives in full sun A site with reflected heat, such as against a stone wall or building, provides an extra growth boost Avoid planting in shady, soggy areas. For best results, prepare a raised planting bed for improved drainage. Placement is also crucial when planting multiple Adams Needle specimens. Allow plenty of room between plants to accommodate their substantial mature size.
Dig a Properly Sized Planting Hole
The planting hole for your Adams Needle must be wide and deep enough to accommodate the root system. As a rule of thumb, dig a hole two to three times the width of the nursery pot or root ball. The depth should be approximately six to twelve inches deeper than the length of the roots. This extra depth allows you to amend and improve the soil that will support continued root growth.
Carefully Remove from the Nursery Pot
When transplanting from a nursery container, gently loosen the root ball before lifting the plant. Slowly remove the pot, trimming any circled or tangled roots. Gently tease apart the root mass to encourage outward growth into the surrounding soil. Be careful not to damage the central taproot, which anchors the plant.
Position at the Correct Planting Depth
Here is the crucial step where many gardeners unintentionally go wrong. When backfilling the hole, be very careful not to plant the Adams Needle deeper than the soil level in the nursery pot. Burying the trunk results in soil buildup around the crown, causing rot and decline. The crown where the roots meet the stem should always remain at or just above the soil surface.
Backfill and Water Thoroughly
Refill the planting hole with the amended native soil. If needed, create a raised mound to ensure the crown sits at the proper height. Water deeply after planting to saturate the root zone and eliminate air pockets. Avoid fertilizing at time of planting to prevent root damage. Spread an organic mulch around the base to retain moisture and reduce weeds.
Allow Time to Establish Roots
Resist the temptation to excessively water or fertilize a newly planted Adams Needle. Too much moisture can lead to rot when roots are not fully established. Limit water to once a week, providing about an inch of moisture if rains are lacking. The growing root system will expand more vigorously if not over-stimulated with fertilizer at this early stage.
Ongoing Care After Planting
During the first year after planting, the Adams Needle roots are developing and adapting to their new environment. Monitor soil moisture levels, watering thoroughly but infrequently to encourage deep rooting. Apply a balanced organic fertilizer or compost tea a few times during the growing season. After establishment, Adams Needle plants are highly resilient and require minimal care to thrive for decades.
How to Grow an Adam’s Needle Yucca Plant
Yucca plants grow best in full sun and dry sites. While they are very tolerant of drought, sandy or compacted soil and salt spray, Adam’s needle yucca cannot tolerate wet or continually damp soils. The roots will rot in cool climates where they are exposed to extremely cold, wet springs.
When planting, be sure to allow at least two to three feet (.61-.91 m.) of space between your yucca and any other plants. Create a hole two times larger and deeper than the root ball, which should be planted level with the ground. Give it a deep watering.
Beware! The dangers of the Yucca plant.
FAQ
How deep do you plant a yucca plant?
How to plant an Adams needle?
How deep do plants need to be planted?
Are Adams needles annuals or perennials?