Lycium californicum aka California Desert Thorn

Lycium californicum is an easy-to-grow native shrub once established. It thrives on neglect, being highly drought-tolerant and adapted to challenging coastal conditions including salt spray, sandy soils, and summer drought. This makes it an excellent low-maintenance choice for California coastal gardens, requiring minimal watering and care after the first year of establishment.

This mounding shrub typically reaches 0.5-2 meters (1.5-6 feet) in height and can spread 2-3 meters (6-10 feet) wide, often wider than tall. Growth rate is moderate.

Lycium californicum is native to the coastal regions of southern California, from Santa Barbara County south to northern Baja California, Mexico, including the Channel Islands. Unlike its desert-dwelling relatives in the Lycium genus, this species is strictly coastal, found on coastal bluffs and in coastal sage scrub communities at elevations below 150 meters (500 feet). A separate variety (var. arizonicum) occurs in the Sonoran Desert of southern Arizona.

Flowers appear primarily from March through August, sometimes as early as December with early rains. The small bell-shaped flowers are about 6 mm across, white with attractive pale purple lines or streaks, fading to tan as they age. Unusually for the nightshade family, flower parts are arranged in fours. Flowers appear in clusters of 2-3 and are followed by bright red berries that attract birds.

The berries of Lycium californicum are edible for humans, described as tasting like a tart, salty tomato, though somewhat bland. However, the related species Lycium chinensis is listed as toxic to dogs and cats. Since specific toxicity data for L. californicum regarding pets is not available, caution should be exercised. If concerned about pet ingestion, contact your veterinarian or the ASPCA Poison Control Center.

Lycium species can be propagated by seeds, softwood cuttings, or semi-hardwood cuttings. For seeds, soak in warm water for 24 hours to improve germination, then plant 1 cm deep in well-draining soil mixed with sand or perlite. Germination can be slow and erratic, taking weeks to months. For cuttings, use softwood cuttings dipped in rooting hormone, placed in freely draining medium, and kept warm and bright but out of direct sun until rooted.

Yes, Lycium californicum is exclusively an outdoor plant, hardy in USDA zones 9-10. It's ideal for coastal California gardens and similar Mediterranean climates. The plant tolerates salt spray, sandy soils, and summer drought. It goes dormant in summer, dropping leaves and appearing dead, but responds rapidly to rain. Plant in full sun with well-draining soil for best results.

Lycium californicum is primarily pollinated by native bees, though other insect pollinators also visit the flowers. The flowers are an important nectar source for bees and butterflies, especially in fall. The resulting berries then provide food for numerous bird species and small mammals, making this plant valuable for wildlife gardens.

In its native Mediterranean climate, Lycium californicum follows a natural cycle of summer dormancy. During summer drought, the plant drops its leaves and may appear dead—this is normal and not a cause for concern. It will leaf out rapidly when rains return in fall. Avoid overwatering during dormancy. The main growing season is late fall through spring when coastal California receives rainfall.

Yes, the bright red berries are edible and were traditionally used as food by Southwest Native peoples. They taste similar to a tart, salty tomato, though somewhat bland and slightly bitter. Berries can be eaten raw in limited quantities (several ounces at a time), or dried or stewed. Like its Asian relative the goji berry (Lycium barbarum), the berries contain beneficial antioxidants and zeaxanthin.

Lycium californicum is generally pest-resistant when grown in appropriate conditions. The plant serves as a larval food source for several native moth species including the Mexican agapema silkmoth, sphinx moths, and crambid snout moths—this is beneficial for wildlife rather than problematic. Root rot can occur if planted in poorly draining soil or overwatered, especially during summer dormancy.

California Desert Thorn should be watered regularly, allowing the soil to dry out between waterings.

California Desert Thorn loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

California Desert Thorn thrives in bright and direct sunlight. To ensure your plant receives enough light to survive, place it less than one foot from a window. The current weather in your area may affect the placement in your home. For example, if you live in a region that has longer and more intense periods of sunlight, then you may want to place the plant farther away from the window to avoid direct sunlight and reduce the risk of sunburn. Alternatively, if you live in a region with relatively milder temperatures and less intense sunlight, then you may be able to place the plant closer to the window for increased exposure. Ultimately, the current weather in your area should be taken into consideration when determining the best placement for your California Box Thorn.