Ballona’s beautiful mustard plant superbloom is a challenge for native species

By Gary Walker

The Ballona Wetlands is overwhelmed with mustard plants

From the Westchester bluffs, the Ballona Wetlands look like a sea of bright yellow. Following the wettest January and February in years, wild mustard plants have become the stars of a Playa del Rey superbloom. But where many passersby see beauty, wetlands biologists see trouble ahead.

“Everyone gets excited about the ‘wildflowers’ — which they are not — and they love all the yellow, but in a month or so everything will dry up and become a field of brown dead brush, which is a huge fire hazard and another obstacle to restoration of native plants and habitat for wildlife,” notes Neysa Frechette, field biologist for the wetlands protection and restoration group Friends of Ballona Wetlands.

The newly ubiquitous black mustard plants (brassica nigra) are an invasive, non-native species that competes with essential native plant species for nutrients, sunlight, water and space to grow. They’re sturdy and hard to remove, creating new obstacles for wetlands caretakers.

“Between the black mustard plants and the garland chrysanthemum [yellow and white daisies], we could hardly even move through Area A [the wetlands near Marina del Rey] to do our bird survey,” Frechette says.

The mustard plants are extremely tall this year — some as high as six feet — and more prevalent than the 2017 Ballona mustard bloom, she adds, blaming supercharged growth on winter’s drought-busting rainfall.

The 5.52 inches of rainfall recorded at LAX in January made it the second-wettest January of the past five years behind 2017, according to National Oceanic and Atmospheric Administration (NOAA) data. And February brought an additional 4.36 inches to LAX, exceeding the 30-year monthly median by more than an inch.

All that rain was a boon for some Ballona denizens, however — particularly of the winged variety.

“This amount of rain fuels the salt pan in the wetlands, where organisms will now be ready to come forth and blue herons, egrets and other shore birds can drink more often,” points out Margot Griswold, a local restoration biologist.

But black mustard isn’t the only interloper taking advantage. Carnation spurge [aka euphorbia terracina], a dense weed with strong roots and carnation-like blooms, is also spreading extensively this year.

“The main obstacle is that these plants out-compete native plants and are often hard to remove. They will likely never
be eradicated completely. We have a constant battle against them because
they seed prolifically and grow quickly, taking up space and resources from our native species,” Frechette laments.

Friends of Ballona Wetlands, she says, is actively seeking volunteers to remove invasive flora and restore native species.