Trichostema lanceolatum
vinegar weed
Overview
Trichostema lanceolatum is an aromatic annual herb 8-24 in (20-60 cm) tall, branching from an erect central stem. The whole plant is covered in glandular hairs and releases a strong camphor- and vinegar-like odor when touched, the source of its common names. Leaves are opposite, lance-shaped, 0.8-2.4 in (2-6 cm) long, and gray-green. From late summer into fall it bears two-lipped tubular flowers 0.2-0.4 in (6-10 mm) long, blue to violet, each with four long stamens that arch well beyond the petals in a curved arc. The flowers cluster in the upper leaf axils along the branch tips. It germinates with spring moisture, flowers as the soil dries, and completes its life cycle in a single season. The species colonizes dry fields, fallow grain stubble, roadsides, and other open disturbed ground, often forming large stands. Because it appears in cultivated fields after harvest, it is treated as a weed in some farmland. The plant dies back completely at the end of the season, leaving only seed.
Native Range
Native to the California Floristic Province, from southern Oregon through California to northern Baja California, Mexico. It grows below about 5,000 ft (1,500 m) in valley grasslands, foothills, and disturbed open ground.Suggested Uses
Grown occasionally in native plant, pollinator, and habitat plantings for its late-season nectar in dry climates. Direct-sown on open ground, it suits restoration of disturbed sites and dry meadows.How to Identify
Appearance
Size & Dimensions
Height8" - 2'
Width/Spread8" - 1'6"
Colors
Foliage Colors
Bloom Information
Flowers from August to October, after most surrounding annuals have dried. Blooms are blue to violet, 0.2-0.4 in (6-10 mm) long, with conspicuously arched stamens. Bees work the flowers through the autumn dry season.
Detailed Descriptions
Flower Description
blue to violetFoliage Description
gray-greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Grows in full sun on dry, well-drained sandy, loamy, or clay soil with a pH near 6.0 to 7.5. As a drought-adapted annual, it needs no irrigation and germinates on residual spring moisture. It tolerates poor, compacted, and disturbed soil where little else establishes. Overhead summer water is unnecessary and can promote damping-off in seedlings. Plants set abundant seed that carries the population to the next season. No winter protection applies, since the plant completes its cycle before frost.Pruning
No pruning is needed for this annual. Plants are pulled or cut at season's end if seed spread is unwanted. Removing flower heads before seed set limits spread into adjacent ground.⚠️ Toxicity Warning
UnknownPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
fall or early spring
Days to Maturity
90–150 days
Plant Spacing
12 inches