Stonecrop, a common name used for plants in the genus Sedum and Hylotelephium, is overwhelmingly classified as a perennial plant. This designation means that stonecrop lives for more than two years, with its root structure surviving through the dormant season to return with new foliage each spring. A perennial life cycle contrasts with an annual plant, which completes its entire life cycle within a single growing season before dying off completely. With over 400 varieties, most stonecrops encountered in gardening are reliably perennial.
Understanding the Perennial Nature
Stonecrop survives year after year by employing a strategy of hardiness and dormancy. As a succulent, the plant stores water in its thick, fleshy leaves and stems, enabling it to endure periods of drought and heat. This succulent nature allows it to survive a wide range of conditions, often thriving in USDA Hardiness Zones 3 through 9, depending on the specific variety.
The key to its perennial survival through winter is the storage of energy within its roots and crown. In colder climates, the above-ground foliage of many varieties will die back completely, entering a state of dormancy to protect the core plant from freezing temperatures. This energy reserve allows the plant to regenerate new growth from the base once warmer temperatures return, effectively resetting the visible plant cycle each season.
Varieties of Stonecrop Growth Habit
Stonecrops are typically divided into two distinct growth types that impact their garden use. The first group is the Creeping or Trailing Stonecrops, which function as low-growing groundcovers. These varieties, such as Sedum spurium or ‘Angelina’ stonecrop, spread horizontally, forming dense mats of foliage that rarely exceed a few inches in height. They are valued for their ability to fill gaps and thrive in challenging, rocky areas.
The second major category is the Upright or Tall Stonecrops, which form distinct, clump-forming mounds. These taller plants, including popular varieties like ‘Autumn Joy,’ can reach heights of up to two feet and are often botanically reclassified under the genus Hylotelephium. Upright stonecrops provide vertical structure and typically feature large, dense flower heads that bloom from late summer into fall, offering late-season color.
Maintaining Stonecrop for Year-After-Year Growth
To ensure stonecrop successfully returns and maintains vigor, specific maintenance practices are beneficial. Proper soil and drainage are paramount for the long-term health of the plant, preventing root rot during dormant periods. Stonecrop performs best in lean, well-draining soil, such as sandy or gravelly mixes, as rich or water-retentive soil can compromise its root crown, especially in winter.
Pruning is another important practice, particularly for the upright varieties, which can be done in either late fall or early spring. Cutting back the dead stalks of the previous year’s growth in the spring clears the way for new shoots to emerge from the perennial crown. Many gardeners choose to leave the spent flower heads throughout winter for visual interest, cutting them down just before new growth starts.
For mature plants, division every few years helps rejuvenate the clump and ensures continued perennial health. When the center of a stonecrop clump begins to die out, it signals the need for division, which is best performed in the spring as new growth begins. The clump can be dug up, separated into smaller sections with healthy roots, and replanted at the same depth to establish new, vigorous colonies.