Wild or Opium Lettuce (Lactuca virosa) is grown medicinally for the milky white sap that oozes from the plant when cut or broken.

The whole plant is rich in a milky sap that flows freely from any wounds. This hardens and dries when in contact with the air. The sap contains "lactucarium", which is used in medicine for its digestive, diuretic, sedative and mildly narcotic properties. Lactucarium has the effects of a feeble opium, but without its tendency to cause digestive upsets, nor is it addictive. It is taken internally in the treatment of insomnia, anxiety, hyperactivity in children, dry coughs, rheumatic pain etc. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower. It is collected commercially by cutting the heads of the plants and scraping the juice into china vessels several times a day until the plant is exhausted. This species contain more lactucarium then any other Lactuca species. An infusion of the fresh or dried flowering plant can also be used. The plant should be used with caution and with the supervision of a skilled practitioner.

Scatter seeds on moist soil, and press them lightly into the soil. Just barely cover the seed as Lactuca needs sunlight to germinate. Germination takes 5 days to two weeks.

Transplant seedlings to rich, moist soil and full sun, spacing them 2 ft apart.
Wild Lettuce is a biennial, which means in the first year it will make a rosette of leaves, and in the second year the flower stalk(s) will shoot up in early to mid summer to 4-6ft and produce seeds in late summer/early fall. If you're lucky, it will make seeds the first year.

Wild Lettuce is hardy to zone 6 (-10F/-23C).