Tagetes lemmonii aka Lemmon's Marigold

Tagetes lemmonii is an easy-to-grow, low-maintenance shrub that thrives on neglect once established. It tolerates drought, poor soils, and requires minimal care beyond occasional pruning. The main requirements are full sun exposure and well-drained soil—avoid heavy clay or waterlogged conditions. Plants are naturally pest-resistant due to their aromatic oils and will reward minimal effort with months of cheerful golden blooms.

Tagetes lemmonii thrives in warm conditions and is hardy in USDA zones 8-11. It can tolerate temperatures down to about -7°C (20°F), though plants may die back to the ground in hard frosts. In zone 8, expect the plant to freeze back in winter but regrow vigorously from the roots in spring. In zones 9-11, it remains evergreen year-round. The plant struggles with extreme heat above 38°C (100°F) and will need afternoon shade and extra water in very hot climates.

In late winter or early spring, prune plants back by one-third to remove frost-damaged growth and encourage dense, compact form—this also stimulates abundant fall flowering. During summer, provide occasional deep watering in hot climates but avoid overwatering. Fall through spring is the main blooming period when the plant requires the least intervention. In cold zone 8 areas, apply mulch around the base before winter to protect roots from hard freezes.

Tagetes lemmonii is highly aromatic, releasing a distinctive complex fragrance when the foliage is brushed or crushed. The scent is often described as a unique blend of lemon, mint, marigold, and passionfruit—hence one of its common names, Passionfruit Daisy. Some describe it as pungent or musky, while others find it pleasantly citrusy. This strong fragrance is what makes the plant effective at deterring deer and many pest insects.

Tagetes lemmonii has an unusual blooming period, flowering primarily from fall through spring when many other plants are dormant. The golden-yellow, daisy-like flowers measure about 5 cm (2 inches) across with darker yellow centers. The plant is photosensitive, meaning flowering is triggered when days grow shorter in autumn. In mild climates, blooming can continue for up to 10 months, providing valuable late-season color and nectar for pollinators.

Beyond the standard species, two notable dwarf cultivars are available for smaller spaces. 'Little Lemon' is a compact form staying under 30 cm (1 foot) tall, perfect for container growing or fronting taller perennials. 'Compacta' grows 60-90 cm (2-3 feet) tall and wide, offering a more manageable size while retaining the species' characteristic fragrance and golden blooms. Both cultivars have the same growing requirements as the species.

In USDA zones 9-11, Tagetes lemmonii grows as an evergreen perennial year-round. In zone 8, the plant may freeze to the ground in winter but typically regrows from the roots in spring—applying mulch can help protect the root zone. In colder zones 7 and below, treat it as an annual or grow in containers that can be moved to frost-free locations for winter. The plant is ideal for xeriscaping, Mediterranean gardens, and drought-tolerant landscapes.

Prune Tagetes lemmonii in late winter or early spring after the main flowering period ends. Cut the plant back by one-third to remove frost-damaged or woody growth and encourage dense, bushy regrowth. The plant responds well to hard pruning and can even be shaped as a hedge. Avoid pruning more than half the plant's height at once. Light deadheading during the growing season can encourage additional blooms, though it's not essential.

Tagetes lemmonii propagates easily by cuttings, seeds, or division. For cuttings, take 8-10 cm (3-4 inch) stem cuttings in spring or early summer, remove lower leaves, dip in rooting hormone, and plant in well-draining potting mix. Roots develop within 4-6 weeks. Seeds can be sown directly after last frost or started indoors, germinating in 1-2 weeks. Established clumps can be divided in early spring by separating the root ball into sections, each with healthy roots.

Tagetes lemmonii is generally pest-resistant thanks to its aromatic oils. Occasionally, aphids or whiteflies may appear and can be treated with insecticidal soap or neem oil. The main disease concern is powdery mildew, which can develop in humid conditions with poor air circulation—ensure adequate spacing and avoid overhead watering. Root rot can occur in poorly drained or overwatered soils. The plant's natural fragrance deters deer, rabbits, and many garden pests.

Tagetes lemmonii is native to southern Arizona in the United States and the states of Sonora, Sinaloa, and Chihuahua in northwestern Mexico. It grows naturally in canyons, cliff faces, stream banks, grasslands, and pinyon-juniper woodlands at elevations between 1,200-2,400 meters (4,000-8,000 feet). The species was discovered in the Santa Catalina Mountains of Arizona by botanists John Gill and Sara Plummer Lemmon in the late 19th century.

Tagetes lemmonii is primarily pollinated by insects, particularly bees and butterflies that are attracted to its golden-yellow flowers. The plant's late-season blooming period (fall through spring) makes it a valuable nectar source when many other flowers have finished. While the aromatic foliage deters many pest insects and deer, pollinators are drawn to the flowers regardless of the scent. Some Tagetes species are also pollinated by beetles in their native range.

Tagetes lemmonii has traditional medicinal applications among indigenous peoples of the American Southwest. Tea made from the plant is used to soothe gastrointestinal irritation, offering mild anti-inflammatory and analgesic properties for conditions like gastritis and digestive discomfort. Fresh plant tinctures are valued for calming effects on the nervous system. However, pregnant and nursing individuals should avoid use, and those with Asteraceae allergies should exercise caution as the sap may cause skin irritation.

Beyond ornamental value, Tagetes lemmonii serves several practical purposes in the garden. Its aromatic oils make it an effective deer and pest deterrent—plant it near vulnerable plants for natural protection. It's noted as a good mosquito repellent when planted around outdoor living areas. The plant is excellent for xeriscaping and water-wise gardens due to its drought tolerance. Its essential oils contain compounds with documented nematicidal, insecticidal, and antiviral properties.

New growth will sprout from the top of the Lemmon's Marigold as it grows vertically.

Lemmon's Marigold should be watered regularly, allowing the soil to dry out between waterings.

Lemmon's Marigold 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.

Lemmon's Marigold requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Mountain Marigold is always in the right place to thrive.

The Lemmon's Marigold does not need extra humidity. Plants primarily absorb water through their root system, making soil watering the best way to provide humidity to your plants.

The Lemmon's Marigold should be repotted when it has doubled in size or annually, whichever comes first. Providing fresh potting soil with all the essential nutrients each year ensures the plant's well-being, eliminating the need for fertilizer. Remember, plants derive their energy from the sun and not fertilizer.

Ploi lacks confirmed information on the toxicity of this plant. If you, a relative, or your pet accidentally consume plant material with unknown toxicity, it's best to consult a medical expert.