Invasive Wildflowers of the California Coast

Ahh, northern California! What a lovely place! And such a temperate climate! Neither too hot or too cold, too wet or too dry. Goldilocks would have said it was “just right”.

Since the wildflowers are rather sparse in the desert this year, I’m spending time on the California Coast, where there are lovely wildflowers. I was surprised to learn, though, that a lot of the loveliest wildflowers on the coast are actually weeds! California shares this problem with Hawaii and New Zealand. Some of its most prolific invasive plants are so beautiful, it’s hard to think of them as heinous invasives.

Even before the days of the gold rush, people of European descent thought this was a perfect place to call home. Many of them wanted to bring a little taste of their old home here with them, in the form of some of their favorite flowers. They planted them in their gardens, and many of these plants from another continent also found the living conditions “just right”. They went wild, spreading far and wide. The living conditions were so perfect, they overran the flowers that were already here, taking over their lands in much the same way that the Europeans that planted them took the lands from the Native Americans who were already here.

Most of the flowers you think of as synonymous with the California Coast are actually invasives. These invaders are so successful that now we call most of them “naturalized”, instead of invasive. They’re here to stay, no getting rid of them except in select small parcels set aside specifically for native plants.

Since they ARE here to stay, we might as well enjoy them. One good thing about their being non-native – it’s OK to pick THESE particular wildflowers! Here’s a guide to some of the California Coast’s most popular invasives.

Periwinkle

Here’s what “Wildflowers of Northern California’s Wine Country & North Coast Ranges” has to say about the Periwinkle: “It causes displacement of native species, erosion and bank destabilization, and is a host for the insect pests Sharpshooters which carry a pathogen of vineyards and orchards…. This is not a plant for the garden.

Wow. Sounds like a nasty plant. Sure looks pretty, though. Definitely feel free to pick this one, but it won’t do much good. It spreads through its roots much more than it does by its seeds.

Ice Plant

This succulent comes from South Africa. Raised cells on its stems and branches that glisten in the sunlight are why it’s called ice plant. It has thin and scraggly petals that turn from white to pink as they age, and thinner leaves than the very visually similar Sea Fig. Now in the Fig/Marigold family, it was originally classified in the Carpetweed family. When you look at how it grows, it’s easy to see why.

Wild Radish

This is a crucifer, related to the Mustard family, the biggest group of invasives in California. It is the most widespread and prolific invader in the state.

Unlike the domestic variety, it’s not the root you eat on this one. It’s the fat, wavy seedpods. There are a few different species that usually grow in close proximity and hybridize.

Wild Garlic

Since we’re getting culinary here, thought I’d mention Wild Garlic. There are many native wild onions in California, but this is not one of them. It’s best to eat before it flowers. The whole plant is edible.

To me, these delicate bells look, but don’t smell, like they should be in a wedding bouquet!

 

Bermuda Sorrel

Also known as Bermuda buttercup, fields and fields of these flowers bring sunshine even on a cloudy day all winter long. But they don’t bring sunshine to native plants and animals. As they drive out the native plants that local animals depend on, it becomes a monoculture. Hawks, owls and coyotes soon leave, as the rodents they depend on get scarce. Bermuda Sorrel is almost impossible to eradicate, and the areas it colonizes soon become great golden wastelands.

Bermuda Sorrel is originally from Africa. It is a relative newcomer, only beginning to be a problem in the 1980’s. Now many invasive plant experts consider it the most dangerous invasive on the coast.

Another name for this plant is sourgrass. It makes an interesting addition to a spring salad, but use it sparingly. An oxalis, this plant can be toxic if eaten in too great a quantity.

Sea Fig

Another native of South Africa, Sea Figs and their close relatives Hottentot Figs were brought over in the early 1900’s to stabilize ground by railroad tracks. It seems this plant decided that a day at the beach was better than workin’ on the railroad (I’d have to agree!), because it soon spread to the Coast and really took over. This plant is now ubiquitous with the California Coast. By the way, the Sea Fig IS a member of the Fig family and does have a fruit, but it doesn’t taste especially good.

Scotch Broom

I hate this plant. Think of a cross between a cactus and a thistle. Not a pretty picture, huh? It’s a good description of the Scotch Broom, a very thorny bush that grows in inpenetrable thickets. This is one nasty plant. It will poke and stab you if you get anywhere near it. If you want to pick some for your invasive bouquet, better wear some stout gloves!

It’s horribly invasive. It is invasive all up and down the West Coast. Not only does it overrun coastal areas, it grows in disturbed ground where timbering has been done, outcompeting tree seedlings and not allowing the forest to grow back. It has cost the timber industry $47 million a year in Oregon alone! This is the worst invasive plant in New Zealand, where it has overrun the entire country. Now you know why I hate this plant. But it is pretty.

Calla Lily

Another South Africa native, these, along with daffodils, are garden plants gone feral. I have a hard time considering them invasive, although, of course, they are. They are not nearly as bad as the other invasives in this little guide, though! I’d rather just think of them as “introduced”.

The trouble with all these plants is just that they’re a bit too successful. They outcompete the “little guys”, the more delicate natives. Many form mats and propagate through their roots, leaving no room for the native plants to grow. It doesn’t mean they’re not interesting plants.

I’ll do a post on the native wildflowers in April. Until then, enjoy the beautiful weeds of the California Coast. Remember that by definition, a weed is just a plant growing where someone doesn’t want it to grow. “Would a rose by any other name smell as sweet?”