Twelve years ago, gardener Jo Casterline flanked her rock-lined gravel path in Poway, California, with plants that thrive in fast-draining decomposed granite and require minimal supplemental water. Among them were orange and yellow California poppies; their sunny blooms have returned every year since.

Now Casterline says her poppy-lined walkway "is the best part of my garden, and I don't do anything to make it happen. It just comes back, year after year." And because the poppies and other annuals die back each fall and come up the next spring, Casterline's pathway never looks the same two years in a row. "It's always a surprise," she says of the ever-changing color show.

Think of these kinds of annuals as polite reseeders. If you'd like to introduce some to your own garden, fall is the perfect time to start them in mild-winter climates. (In cold-weather areas, wait until early spring to sow seeds.)

Keep in mind that there's a fine line between a well-behaved reseeder and an aggressive pest, and the difference often depends on climate. Our list includes corn cockle, for instance, even though this wispy annual turns up on noxious-weed lists in some areas. It's a pest only in the Southeast; in the West we find it almost too polite ― it reseeds rather sparsely.

Ten of our top reseeders are listed here:

California desert bluebells (Phacelia campanularia). Bell-shaped, dark blue flowers; gray-green, coarse-toothed leaves. Grows 6 to 18 inches tall and wide. Sunset climate zones 1-3, 7-24.

California poppy (Eschscholzia californica). Satin-textured, single-petaled flowers, pale yellow to deep orange, on stems 8 to 24 inches long. Zones 1-24; H1.

Corn cockle (Agrostemma githago). Mauve-purple flowers with darker veins. Grows 2 to 3 feet tall and 1 foot wide. Good for cutting. Zones 1-24.

Desert marigold (Baileya multiradiata). Inch-wide, bright yellow flowers; gray-green foliage. Grows 1 to 1 1/2 feet tall. Native to Western deserts. Zones 1-3, 7-23.

Godetia (Clarkia amoena). Single or double flowers in lilac to reddish pink and blotched or streaked with crimson. Grows 18 to 30 inches tall. Good cut flower. Zones 1-24.

Honeywort (Cerinthe major). Upper stems bear sprays of nodding, tubular, violet-blue flowers; fleshy stems and leaves. Grows 2 feet tall and as wide. Attracts bees. Zones 1-24.

Larkspur (Consolida ajacis). Blossom spikes densely set with flowers in shades of white, blue, lilac, and pink above finely cut, ferny leaves. Grows 1 to 4 feet tall. Zones 1-24.

Love-in-a-mist (Nigella damascena). Blue, rose, or white spurred flowers, followed by attractive seedpods (useful in dried arrangements). Grows 1 to 1 1/2 feet tall. All zones.

Shirley poppy (Papaver rhoeas). Single or double cup-shaped flowers in shades of red, pink, orange, and white, including bicolors. Grows 3 feet tall. Zones A1-A3; 1-24 (best in cool-summer areas).

Sweet alyssum (Lobularia maritima). Clusters of tiny, four-petaled white flowers on low mounds that grow 1 foot tall and wide. In mild climates, blooms nearly year-round from self-sown seedlings. Attracts bees. All zones.