Lactuca virosa, commonly known as Wild Lettuce, is a biennial plant belonging to the Lactuca genus. It is sought after for its milky-white sap, historically referred to as lactucarium. This latex contains sesquiterpene lactones, primarily lactucin and lactucopicrin, which contribute to the plant’s traditional uses.
Identifying Wild Lettuce: What You Are Buying
True Wild Lettuce, Lactuca virosa, grows as a stout biennial, often reaching heights of four to seven feet when it sends up its flowering stalk. The leaves are typically a waxy, grayish-green, with margins that are slightly undulating or lobed. When any part of the plant is cut or damaged, it exudes a noticeable white, sticky latex sap.
The most reliable marker for identification is the presence of small, stiff hairs or soft spines running along the underside of the central leaf vein, or midrib. While the plant is sometimes referred to as Prickly Lettuce, the prickles on L. virosa are typically softer and less aggressive than those found on L. serriola.
The plant produces numerous small, pale yellow flowers, resembling miniature dandelions, clustered at the top of the tall stalk during its second year of growth. These flowers appear from mid-summer into early fall. The white, milky sap and the spiny midrib are the most important characteristics to distinguish L. virosa from similar-looking weeds like Sow Thistle.
Commercial Sources for Plants and Seeds
The most direct way to acquire Lactuca virosa is through online specialty herb nurseries and seed banks, which offer both live plants and seeds. Purchasing seeds is the most cost-effective method, and online seed vendors specialize in medicinal or heirloom herb varieties. These suppliers typically offer fresh seeds with high germination rates, often marketed as “Wild Lettuce Seeds” or “Bitter Lettuce Seeds.”
For those seeking a more immediate result, live plants are often available from smaller, independent herb nurseries or through online marketplaces featuring small-scale growers. These live plants are usually sold as young seedlings, which significantly reduces the time needed to establish a mature plant in the garden. When purchasing either seeds or live plants online, verify the vendor’s reputation and ensure they specify the botanical name, Lactuca virosa.
Local agricultural markets, farmer co-ops, or specialized plant sales may occasionally feature Lactuca virosa. However, these local sources can be inconsistent, making online suppliers the more reliable option. While seeds are inexpensive, live plants offer the advantage of bypassing the delicate germination and seedling stage, providing a faster track to a mature, harvestable specimen.
Essential Care and Cultivation Guidelines
Wild Lettuce is a hardy plant that adapts well to various conditions, generally preferring a site with full sunlight, although it can tolerate partial shade. The plant thrives in well-draining, loamy, or sandy soil, and it does not require overly rich ground to flourish. A soil pH ranging from neutral to slightly acidic is ideal for optimal growth.
Consistent soil moisture is necessary for successful germination and the establishment of young seedlings, but the plant must not be left in waterlogged conditions. Once established, Lactuca virosa becomes relatively drought-tolerant, though regular watering during dry spells will encourage better growth. A balanced fertilizer can be applied every four to six weeks during the primary growing season to support its vigorous development.
Because the plant can grow quite tall, adequate spacing is necessary to allow for air circulation and prevent overcrowding. Seedlings should be thinned or transplanted to be about six to twelve inches apart. As a biennial, the plant forms a low rosette of leaves in its first year and sends up its flowering stalk in the second year, which is when the plant is typically harvested when in full bloom.