Sweet alyssum is a common flowering plant, easily available in seed or in pony packs at your local nursery. It is usually planted in the fall in Southern California. This is what it looks like today (March 19). Sweet alyssum happens to be extremely useful in the edible ecological garden. First, in addition to the sweet smell of the flowers, the leaves and flowers are edible, with a peppery, cress-like taste. Perhaps more importantly though, alyssum attracts multiple beneficial insects to the garden, and its small size makes it easy to tuck in on the borders of vege-beds, around fruit trees, or many other places in the garden.
Specifically, sweet alyssum is known to attract three main categories of beneficial predator insects (those that eat pest insects in the garden): 1) Minute pirate bugs (who eat aphids, thrips, mites, psyllids, and insect eggs), 2) Parasitic wasps (who lay eggs in aphids, beetles, flies, moths, sawflies, mealy bugs, and scales. A The larva hatch and eat their way out, killing the host), 3) Hover flies (whose larva feed on aphids). A The flowers also attract butterflies and bees.
Here are a couple more images of sweet alyssum along with California poppy under a young Spice Zee Nectaplum tree (It's a cross between a nectarine and a plum).
Scott Kleinrock is the Ranch project coordinator at The Huntington.