Galium andrewsii aka Phloxleaf Bedstraw

Galium andrewsii is a challenging plant to cultivate outside its native California habitat. It requires specific conditions including full sun, excellent drainage, and dry summer conditions typical of Mediterranean climates. The species is dioecious, meaning you need both male and female plants for seed production. Commercial availability is limited, making it primarily suited for native plant enthusiasts and restoration projects within its natural range.

Galium andrewsii is native to California and Baja California, Mexico. In California, it occurs throughout much of the state, from northern counties like Siskiyou and Del Norte southward to San Diego and Imperial counties. The species grows on ridges and slopes within Yellow Pine Forest, Foothill Woodland, Chaparral, and Pinyon-Juniper Woodland ecosystems at elevations ranging from near sea level to over 8,000 feet.

Galium andrewsii blooms from December through March, taking advantage of California's winter rains. The flowers are small, greenish-yellow, and wheel-shaped (rotate). As a dioecious species, individual plants produce either male or female flowers. Male flowers appear in small clusters, while female flowers grow singly in the leaf axils. Both flower types are similar in appearance with smooth (glabrous) petals.

Galium andrewsii relies on insect pollinators to transfer pollen between male and female plants. Being dioecious (having separate male and female individuals), cross-pollination by insects is essential for fruit and seed production. The plant supports butterflies and their caterpillars, indicating an important ecological relationship with pollinators. After successful pollination, female plants produce small, black, smooth berries.

Galium andrewsii can be propagated by seed or division. For seed propagation, collect the small black berries after they mature and sow in well-draining soil. Since the plant is dioecious, you'll need seeds from pollinated female plants. Division of established clumps in early spring or fall is another option. Like other California natives, seeds may benefit from a period of cold stratification to break dormancy. Maintain dry conditions similar to the plant's native chaparral habitat.

Galium andrewsii is exclusively an outdoor plant suited to Mediterranean-climate gardens within USDA zones 8-10. It thrives in full sun with well-draining soil and dry summer conditions. Plant it on slopes, in rock gardens, or native plant beds where drainage is excellent. This California native works well in chaparral-style landscapes and requires minimal summer irrigation once established. It's ideal for habitat restoration and native wildlife gardens.

Three subspecies of Galium andrewsii are recognized: subsp. andrewsii (Andrews' Bedstraw), subsp. gatense (Serpentine Bedstraw or Phlox-leaf Serpentine Bedstraw), and subsp. intermedium. While morphologically difficult to distinguish, they are considered distinct based on molecular data and chromosome numbers. Subspecies gatense is particularly notable for its association with serpentine soils in Southern and Central California, growing on dry slopes at elevations from 700-8,500 feet.

Galium andrewsii tolerates a range of temperatures consistent with California's Mediterranean climate. Based on its native range, plants experience coldest month averages of 38.8°F to 54.1°F and hottest month averages of 60.1°F to 79.1°F. The species occurs from low coastal areas to elevations over 8,000 feet, indicating good cold tolerance for a California native. It's adapted to hot, dry summers and mild, wet winters.

Galium andrewsii is a compact, low-growing plant that reaches only 5-22 centimeters (2-9 inches) in height. It forms cushion-like or mat-forming clumps that spread wider than they are tall. The slender stems have four angles and bear whorls of four needle-like leaves, each 4-11mm long. The plant's color ranges from green to silvery depending on conditions. This small stature makes it suitable for rock gardens, borders, and groundcover applications.

Galium andrewsii is generally resistant to pests and diseases when grown in appropriate conditions. The main concerns are root rot from overwatering or poor drainage, which can be fatal to this drought-adapted species. Maintaining dry conditions, especially in summer, and ensuring excellent soil drainage are the best preventive measures. The plant supports butterfly and moth caterpillars, which is a benefit for wildlife gardens rather than a pest problem.

Phloxleaf Bedstraw should be watered regularly, allowing the soil to dry out between waterings.

Phloxleaf Bedstraw 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.

Phloxleaf Bedstraw 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 Phlox Leaved Bedstraw is always in the right place to thrive.

The Phloxleaf Bedstraw 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.