The term “Lamia plant” frequently refers to species within the Lamium genus, most commonly Lamium maculatum, known as Spotted Deadnettle, and Lamium purpureum, or Purple Deadnettle. These plants possess a dual nature in the garden. Some Lamium species are valued as attractive ornamental groundcovers, while others are common, rapidly spreading garden weeds. This article explores both characteristics, providing insights into their identification, cultivation, and management strategies.
What is a Lamium Plant
Lamium species, members of the mint family (Lamiaceae), share distinct characteristics such as square stems and opposite leaves. These plants are often called “deadnettles” because their leaves resemble stinging nettles, but they lack the stinging hairs. Lamium maculatum, the Spotted Deadnettle, is a perennial that typically grows 6 to 9 inches tall and can spread to form a dense mat. Its leaves are often variegated with silver or white markings, adding to its ornamental appeal, and are generally heart-shaped or triangular with rounded teeth.
In contrast, Lamium purpureum, or Purple Deadnettle, is usually a winter annual. This species grows approximately 4 to 20 inches tall and is characterized by purple-tinged upper foliage and small, tubular, pink to purple flowers. Its leaves are triangular to heart-shaped with shallow lobes. Lamium purpureum is commonly found in disturbed areas like gardens, roadsides, and fields.
Cultivating Lamium as an Ornamental
For those cultivating Lamium maculatum as a groundcover, understanding its specific care requirements ensures thriving growth. This plant flourishes in partial to full shade, especially the silver-leaved varieties, which benefit from more light to maintain their color. While it prefers moist, well-drained, humus-rich soil, Lamium maculatum can tolerate a range of soil types and is quite drought-tolerant once established. Consistent moisture is important for newly planted specimens until their root systems develop.
Regular watering is beneficial when the soil partially dries out. A balanced fertilizer (e.g., 10-10-10 N-P-K ratio) can be applied every 4-6 weeks during the growing season to promote healthy growth and vibrant foliage. Pruning helps maintain its shape and encourages new growth; leggy or overgrown stems can be trimmed in spring or after flowering. Popular ornamental varieties include ‘White Nancy’ with silvery-white leaves and white flowers, ‘Orchid Frost’ featuring silvery leaves with orchid-pink flowers, and ‘Pink Pewter’ with silvery-green leaves and rose-pink flowers.
Managing Lamium as a Weed
Certain Lamium species, particularly Lamium purpureum, are often considered unwanted weeds due to their rapid spread and ability to compete with other plants. This plant is a prolific seeder, with each plant producing thousands of seeds that can remain viable in the soil for several years. It also has a shallow root system, which makes manual removal feasible for small infestations. When hand-pulling, it is important to remove the entire plant, including the roots, to prevent regrowth from fragments.
Cultural practices can also help manage its presence. Maintaining a thick, healthy lawn or garden can prevent Lamium purpureum from establishing, as dense plant cover leaves no room for its seeds to germinate. Mulching can also suppress its growth. For widespread or persistent infestations, selective post-emergent herbicides can be used. Herbicides containing 2,4-D or Dicamba are effective. Applying pre-emergent herbicides in late fall or early winter, before germination, can prevent its establishment.
Beyond the Garden: Other Aspects of Lamium
Beyond its roles as an ornamental or a weed, Lamium plants offer additional dimensions. Ecologically, Lamium purpureum provides an important early-season nectar source for pollinators, including bees, when few other food sources are available. Its flowers are particularly attractive to bumblebees and honeybees.
Some Lamium species, including Lamium purpureum and Lamium maculatum, have edible qualities. Young leaves and tops of Lamium purpureum can be used in salads or stir-fries, and the flowers can be candied. Historically, Lamium species have been used in traditional medicine for various ailments, with some research indicating properties such as anti-inflammatory and antibacterial effects. While Lamium purpureum is widely naturalized in North America and can be aggressive, it is generally not considered one of the most damaging invasive plants, though it can compete with native species in disturbed habitats.