Eriodictyon californicum aka California Yerba Santa

California Yerba Santa is an easy-to-grow native shrub once established. It is naturally adapted to harsh chaparral conditions with minimal water and poor soils. The plant tolerates drought, various soil types from sandy to clay, and requires little maintenance. In cooler climates (below Zone 7), it may need protection from frost or placement against a warm, sunny wall.

California Yerba Santa typically reaches 1-3 meters (3-10 feet) tall and about 2 meters (6 feet) wide at maturity. It is a fast-growing shrub—rhizomes can extend up to 2.5 meters in a single growing season, and seedlings can reach 50 cm in their first year. The plant naturally forms dense thickets through its spreading rhizomatous root system, creating broader colonies over time.

This adaptable shrub grows in nearly any soil type, from sandy loam to heavy clay. It prefers well-drained soil but tolerates various conditions including serpentine soils. The shallow root system allows it to establish in both thin and deep soils. Soil pH can range from mildly acidic to mildly alkaline. For best results, provide a moderately fertile, well-draining growing medium.

California Yerba Santa is native to Mediterranean climates with dry summers and does not require high humidity. It thrives in the low-humidity conditions typical of California chaparral and woodland environments. The resinous leaf coating helps prevent moisture loss, making the plant well-adapted to dry air conditions.

This native shrub requires minimal fertilization. It naturally grows in moderately fertile to poor soils and is adapted to nutrient-limited chaparral conditions. If desired, a light application of balanced fertilizer in spring can support growth, but excessive fertilization is unnecessary and may promote weak, leggy growth. Avoid high-nitrogen fertilizers.

California Yerba Santa can be propagated from seeds, cuttings, or division of rhizomes. Seeds germinate best after fire or mechanical scarification, emerging 1-3 weeks after disturbance. Division of established rhizomes in late winter or early spring is often the most reliable method. Semi-hardwood cuttings can be taken in summer. Seedlings reach sexual maturity within 2-3 years.

California Yerba Santa produces clusters of funnel-shaped flowers from April through August, with peak bloom typically in May-July depending on location. The flowers range from white to lavender or purple, measuring 8-17 mm in length. They emerge in clusters just above the foliage and are highly attractive to bees and butterflies, serving as a critical nectar source for pollinators.

This plant is insect-pollinated, with bees being the primary pollinators. The flowers are hermaphrodite, containing both male and female organs. California Yerba Santa is an important nectar plant for native pollinators—it serves as the primary nectar source for variable checkerspot butterflies at Jasper Ridge Biological Preserve and is a specific food plant for the pale swallowtail butterfly.

Prune California Yerba Santa in spring or early summer to maintain shape and control size. Avoid cutting into wood older than two years, as the plant regenerates best from younger growth. The shrub naturally responds well to fire and hard pruning, resprouting vigorously from rhizomes. Remove dead or damaged branches as needed throughout the growing season.

California Yerba Santa is hardy to approximately -5°C (23°F) and thrives in USDA zones 7-10 (UK Zone 8). It tolerates hot, dry summers typical of Mediterranean climates. In cooler regions, grow against a sunny, south-facing wall for added winter protection. Winter soil temperatures in its native range frequently drop below freezing without harming established plants.

Yes, California Yerba Santa has distinctively aromatic foliage. The leaves contain aromatic compounds that produce a characteristic resinous scent, though this is often described as somewhat unpleasant or medicinal. The sticky, resinous coating on the leaves contributes to the fragrance. When dried, the leaves develop a sweeter, more pleasant aroma suitable for making aromatic tea.

California Yerba Santa is exclusively an outdoor plant, native to the chaparral and woodland ecosystems of California and Oregon. It thrives outdoors in USDA zones 7-10, growing at elevations from 20 to 1,830 meters. Plant in full sun with well-drained soil. Once established, it requires minimal summer irrigation (twice monthly or less) and is highly drought tolerant.

In spring, new vegetative growth emerges (April), followed by flowering through summer. Minimal watering is needed in summer once established—the plant is adapted to Mediterranean dry summers. Seeds ripen in September and can be collected for propagation. Winter dormancy is minimal as the plant is evergreen, though growth slows. Prune in spring or early summer if needed.

California Yerba Santa is relatively pest and disease resistant due to its aromatic, resinous leaves that are unpalatable to most animals. The bitter taste from aromatic compounds deters browsing by deer and livestock. No significant pest or disease problems are commonly reported. The main ecological concern is the plant's aggressive rhizomatous spread, which can allow it to form dense thickets that compete with other vegetation.

Yes, the leaves are edible and have been used traditionally by Native Americans. Fresh leaves can be chewed for their refreshing taste and to relieve thirst. Dried or fresh leaves make an aromatic, sweet tea. Leaf extracts are commercially used as flavoring in baked goods, ice cream, sweets, and soft drinks. However, consumption is not recommended during pregnancy or breastfeeding, and excessive use may affect mineral absorption.

California Yerba Santa has a long history of medicinal use by Native American tribes and Spanish missionaries. Traditional applications include treatment of respiratory conditions such as coughs, colds, asthma, bronchitis, and tuberculosis. The leaves are used as an expectorant to loosen mucus, and topical liniments reduce fever. Modern research has identified compounds including sterubin and eriodictyol with promising neuroprotective and anti-inflammatory properties. The plant is rated 3/5 for medicinal use.

Beyond food and medicine, California Yerba Santa has limited additional uses, rated 1/5 for other uses. Historically, Native Americans wove the leaves into garments. The plant is valuable for ecological restoration, used to revegetate disturbed lands and overgrazed rangeland. Its fire-adapted nature and ability to quickly colonize burned areas makes it useful for post-fire erosion control and habitat restoration.

California Yerba Santa’s native range is South-western N. America - Oregon to California.

California Yerba Santa should be watered regularly, allowing the soil to dry out between waterings.

California Yerba Santa 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 Mountain Balm.

The toxicity level of this plant has not been officially confirmed by Ploi. If there is a possibility of ingestion of plant material with an uncertain toxicity by you, a family member, or a pet, it is advisable to seek the assistance of a medical professional.