PHOTO BY DEBRA BURROWS Yucca filamentosa in bloom in Clinton County, Pa. in early July.

These days, with unusual weather patterns affecting much of the country, including central Pennsylvania, which is experiencing a second year of drought, many gardeners are looking for tough, reliable plants. Yucca (Yucca filamentosa), sometimes called Adam’s needle, fits the bill. It is both heat and drought tolerant, prefers loose soil but will tolerate clay, and is not picky about soil pH or fertility. Yucca can thrive in full sun as well as partial shade and deer tend to avoid it. The only thing it cannot tolerate is soil that is constantly wet.

Yucca filamentosa is a North American native plant that is hardy in zones 4 through 10. It has broad, stiff, strap-like leaves that can grow up to 30 inches in length. The leaves remain evergreen through the winter and have tiny hairs, or filaments, on their edges, which are the basis for “filamentosa” being a part of the scientific name.

Tall flower stalks arise from the clumps of leaves and can reach up to eight feet in height. The stalks are covered in ivory white to pale yellow panicles of flowers which can last for several weeks and are attractive to pollinators. A yucca in full bloom is a bold and beautiful addition to a landscape.

Yucca plants are slow growers but can live for decades, gradually forming clumps. I’ve had one in my garden for at least 15 years which has now formed a clump approximately five feet wide.

A few years ago, I counted nine flower stalks, each about five feet tall emanating from the clump, making a very bold addition to my mixed border. Even though we are experiencing our second consecutive year of drought, the yucca plants continue to grow and bloom reliably.

Before planting a yucca, there are a few things to consider.

First and foremost, is size at maturity. Although they are slow growing, yuccas will eventually become very large, both in width and height, so site them in a location where they will have plenty of room to spread out without crowding other plants. This is especially important because yuccas have tap roots and are difficult to transplant. Although yucca can do well in partial shade, planting under trees may not be advisable because tree limbs may interfere with the flower stalks, which can reach six to eight feet tall. Care should also be taken not to plant yuccas along a walkway or driveway where humans and pets will frequently come in contact with them. The long, stiff leaves are sharp and pointy and can cause injury. Gloves should be worn when working around them.

In addition to the solid green leaves of the straight species, breeders have developed cultivars with variations in leaf color. These include leaves with a blue-silver tint, as well as leaves with yellow markings or stripes which add color to the garden even when not in bloom. Yuccas can be found at local garden centers and greenhouses and are available online and through catalogs. They are tough, reliable plants that can add beauty to a landscape even in difficult conditions.

Additional information on Yucca filamentosa is available from Ohio State University at plantfacts.osu.edu/tmi/Plantlist/yu_ntosa.html .

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Debra C. Burrows, PhD, is a retired Penn State Extension Educator and a certified Master Gardener. She can be reached at dcb3@psu.edu.