Sedum’s invasiveness varies by species and local conditions. Some varieties grow vigorously, while others can threaten native ecosystems. Understanding these distinctions is important for responsible gardening.
Understanding Plant Invasiveness
An invasive plant is a non-native species introduced to an ecosystem that causes or is likely to cause economic or environmental harm, or harm to human health. These plants aggressively monopolize resources like light, nutrients, water, and space, often harming other species. Not all non-native plants are invasive; some are simply vigorous growers. However, invasive species reproduce rapidly, spread easily, and outcompete native flora for essential resources.
Sedum’s Growth Habits
Sedum, commonly known as stonecrop, is a large genus of succulent plants with fleshy leaves and stems that store water. Most sedums are hardy and drought-tolerant, adapting to various soil conditions, including poor, dry, or rocky soil. They spread through rhizomes, wind- and water-dispersed seeds, and by rooting from detached leaves or stem fragments. This allows some varieties to spread up to one foot per year under ideal conditions.
Identifying Potentially Problematic Sedum Species
While many sedum varieties are well-behaved, certain species spread aggressively and can be invasive in some regions. Sedum acre (Goldmoss Sedum or Biting Stonecrop), native to Eurasia and North Africa, is problematic. It forms dense mats that outcompete native plants and is listed as moderately invasive in some areas. Sedum album (White Stonecrop) also exhibits aggressive, mat-forming growth, rapidly spreading and overwhelming other plants in sunny positions. Sedum sarmentosum (Stringy Stonecrop) and Sedum spurium (Two-row Stonecrop) are also cited as invasive in some areas, forming dense mats that crowd out other vegetation.
Managing Sedum Spread
For sedum varieties prone to vigorous growth, several management strategies can prevent unwanted spread. Planting aggressive types in containers or with physical barriers can restrict their expansion. Regular trimming controls their size and reduces plant material for self-seeding or rooting. Careful disposal of trimmings is important, as even small fragments can root and establish new plants. Manual removal is effective for controlling existing sedum, though complete removal of root fragments is necessary to prevent regrowth.
Choosing Sedum Responsibly
To minimize potential invasiveness, select appropriate sedum varieties. Many Hylotelephium species, previously classified under Sedum, are clump-forming and well-behaved, making them suitable for most gardens. Examples include cultivars of Hylotelephium spectabile (Showy Stonecrop) and Hylotelephium telephium (Orpine or Live-forever), which form upright mounds rather than spreading aggressively. These upright varieties offer vibrant late-season color and attract pollinators without posing a risk of unchecked spread. Before purchasing, check local invasive species lists, as a plant’s behavior varies by region and climate, and responsible selection contributes to maintaining local ecological balance.