Gunnera Chilensis Seed Propagation

Seed Production

• Chilean rhubarb is so prolific it is considered an invasive weed, and the sheer number of seeds it produces is partly to blame. Fruits appear in wintertime and grow on flowering stalks that reach up to 3 feet high. Each drupelike fruit contains seeds, often numbering in the thousands. Wash seeds in tap water to remove pulp. Soaking them overnight at room temperature may improve germination time, although even fresh seeds germinate easily and readily.

Germination and Care

• Chilean rhubarb germination is easy to accomplish. In lab testing conducted by New Zealand Department of Conservation, seeds had a germination rate of 100 percent within 30 days. Many of the fresh seeds germinated in 14 days. Placing seeds in germinating medium with sufficient water-holding capacity, and providing plenty of moisture, will ensure emergence. Chilean rhubarb thrives in moist environments and needs such conditions to grow.

Natural Seed Dispersal

• In its natural environment, birds are responsible for propagating Chilean rhubarb plants, which occurs in spring through summer. In tests by the New Zealand Department of Ecology, scientists found that seeds obtained from bird feces germinated at a faster rate of seven days, versus 14 days in fresh seeds. This suggests that the seeds benefit from passing through digestive systems of birds, which probably removes their outer coating. Blackbirds and white-eyes likely accomplish much of this dispersal. In addition to seed dispersal by birds, Chilean rhubarb also reproduces from stem fragments. When plant parts break off into streams or down slopes, new plants grow from such parts.

Control

• With its prolific growth, habit of shading out other plants and excessive seeding rate, this species has become troublesome in many regions and the Invasive Species Specialist Group, a global network of scientific experts, considers it a serious threat to biodiversity. Even after plants have been removed, it easily recolonizes itself in the area because of the great number of seeds it produces. Remove plants with fire or chemicals and destroy flower heads to prevent spread. Use the removed plants for their edible parts, by peeling and cooking the young leaf stalks.