DID YOU KNOW?
by Shawna Anderson
Spring 2007

PICKLEWEED PLOTS

Anyone who hasn’t noticed all the grading activity occurring in the San Dieguito Lagoon on both sides of I-5 is too busy watching the traffic ahead of them. I hope most of you realize that condos are not going in, but an $80 million, 150-acre wetland creation/restoration project by Southern California Edison (SCE) in partnership with the San Dieguito River Park JPA. SCE has hired a highly qualified restoration team headed by Marathon Construction to create new wetlands and restore the lagoon area. One of the aspects of this extensive wetland restoration effort is to replant areas with wetland species after new wetland areas are established. Salicornia (known as common pickleweed) is the most abundant plant in coastal salt marshes making up at least 90 percent of coastal salt marsh plant cover. One of the reasons for its abundance is its high tolerance for harsh growing conditions such as saline soils and frequent inundation from tidal fluctuation. Coastal salt marsh is just one of the habitat types that will exist in the fully-restored San Dieguito Lagoon.

To find the most optimum growing conditions for planting new stands of pickleweed, SCE’s restoration specialist RECON is conducting test plant plots at the lagoon. Test plots consist of 10’x10’ areas planted with pickleweed seedlings. RECON has established two test plots, each with a different planting scheme to determine which one has a better growth rate for establishing healthy new coverage. The individual plants were propagated from seed collected at the San Dieguito lagoon last year and then germinated at RECON’s native plant nursery. After about six months new plants were transplanted to the test plots. Wetland soil removed from the lagoon area will be used as the planting medium (base and top soils). Wetland base soil is extremely important for successful restoration because it contains native plant fragments, organic matter, salts and other growing properties. These properties help the transplanted seedlings to grow and thrive. Cuttings or fragments from existing plants can be used to establish new plants; however, greater genetic diversity is achieved by growing individual container plants from local seed instead of cut from an existing plant (essentially a clone).

It is anticipated that about 25 total acres of coastal salt marsh with pickleweed seedlings will be seen throughout the lagoon area by 2009. At first, they will look like uniform sticks jutting out of the ground especially from a distance, but by summer the plants will start to spread. However, it will take at least ten years for newly planted areas to fully mature and resemble that of an undisturbed coastal salt marsh. Just as in nature pickleweed will represent the primary species in the coastal salt marsh habitat, but other species such as fleshy Jaumea (Jaumea carnosa), alkali heath (Frankenia salina), saltgrass (Distichlis spicata), and saltwort ( Batis maritima), will also be incorporated. The marsh areas will exist primarily around the fringes of a new lagoon on the west side of I-5 and along the margins of the San Dieguito River on both sides of the freeway.

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