Invasive Plants of California's Wildland

Red apple (Aptenia cordifolia) is a perennial herb, spreading over ground and neighboring vegetation, with small, heart-shaped, dark green succulent leaves interspersed with small, axillary, many-petaled, bright pink to purple flowers that open only in sun. The hybrid red apple (with Platythyra haekeliana) has brighter red flowers.

In California, red apple is found in disturbed places and on margins of coastal wetlands, usually less than 100 feet (30 m) elevation. Naturalized in California, it is reported in central and southern California and on embankments along irrigation waterways in the Central Valley (Hickman 1993). It has naturalized also in Oregon, St. Lucie County, Florida, and along the southern coast of Europe. It is marketed as a fire-resistant (unproven), drought-tolerant ground cover in California. It is planted in parking lot planters, parkways, home gardens, in the urban interface near parks and preserves, and on brush-cleared hillsides and stream embankments. It can tolerate some soil salinity and grows well in dryish, frost-free or almost frost free areas in full sun.

Red apple is native to the eastern coastal region of the Cape Province and Kruger National Park in the Transvaal, both in South Africa, and was brought to California as a horticultural plant (Herre 1971). It is sold widely in plant supply stores. It is known to spread vegetatively by rooting of branches. Seed dispersal capabilty is not known.

When watered, red apple overwhelms all neighboring vegetation, climbing over anything in its path. It is listed as a wildland weed red alert as it has only recently become a problem. It has been used in landscaping adjacent to riparian areas within the urban interface, so it can easily spread into and dominate more natural riparian and wetland areas.

Red apple grows rampant and leggy with water and/or shade and compactly when not watered. Its morphological characteristics indicate that it can over-summer without water and then grow vigorously during the rainy season, although constantly wet soil can cause it to rot. It spreads vegetatively. Nodes root when they touch the ground (Bailey 1949). It blooms in spring and summer. Seeds grow well in sandy, well drained soil and germinate at 60-65 degrees F. More information is needed on seed viability and potential for seed dispersal.

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Little is known about control, but red apple should respond to the same methods as the related sea fig (Carpobrotus edulis) and New Zealand spinach (Tetragonia tetragonoides).

Manual methods: Red apple can be easily removed by hand pulling. However, because of the ability of this plant to grow roots and shoots from any node, all live shoot segments must be removed from contact with the soil to prevent resprouting. If complete removal is not possible, mulching with the removed plant material is adequate to prevent most resprouting, but requires at least one follow-up treatment to remove resprouts.

The herbicide glyphosate (as Roundup®) has been effectively used to kill related sea fig clones at label-recommended concentrations of 2 percent or higher. The addition of 1 percent surfactant to allow penetration of the cuticle on the leaves should improve effectiveness.