Spring hillsides glow with the yellow blooms of Bermuda Buttercup, (or what we kids who chewed on the tart stems called Sour Grass), and mustard, or the purple flowers of radish. Our gardens are heavy with the aroma from white alyssum that seems to bravely succeed when nothing else will. Don’t be fooled: these plants are subversive enemies of our native ecosystems.

Oxalis’s bulbets rob moisture as they reproduce. Alyssum is often found in wildflower seed mixes (even ‘native’ mixes), and is usually the first flower to come up. Like mustard and radish, alyssum’s roots excrete an acid that kills the mycorrhizal fungi upon which our native plants rely. So it’s not that the other plants fail while only good old dependable alyssum succeeds, it’s that alyssum, radish and mustard are sabotaging the soil so they can invade.

Sheet mulching (covering weeds with cardboard and thick mulch) is an excellent way to eradicate small patches of these plants. Planting colorful native flowers helps undo the damage.

For annuals you can’t do better than California poppy. Seen in colorful swaths along the highways with the stunning purple blooms of the nitrogen-fixing Arroyo Lupine, they stabilize slopes and are a great pollinator food source. For very dry, well draining soils Desert Marigold has soft yellow multi-petaled flowers with grey-green foliage.

Supplement your annual wildflower garden with long-blooming perennials. California or San Jose fuchsia sprawl to protect the ground and their brilliant red tubular flowers provide hummingbird food most of the year. ‘Sunshine’ and Cherry Monkey Flower have yellow or red flowers all through spring. Look for more flowers using the Moosa Creek website’s search function.

Sneaky invasives starve our native food chain by killing off our treescapes, chaparral and desert wildflowers.  Controlling these invaders on your own property by planting  a native selection makes you a wildlife hero!