PlantFun
Plant Needs
Sunlight
Full sun to partial sun; thrives in bright, direct sunlight for most of the day, with light afternoon shade in extreme heat
Watering
Water deeply when the top 5 cm of soil is dry; avoid overwatering to prevent root rot
Temperature
Hardy to -15°C; tolerates moderate summer heat but benefits from shade in temperatures above 32°C
Characteristics
- Leaf: Opposite, lanceolate, gray-green foliage with soft pubescence
- Flower: Dense clusters of deep indigo-blue tubular blooms at stem tips
- Stem: Woody, silvery-gray stems that become slightly woody with age
Care Guide
Watering
Keep soil consistently moist but not waterlogged
Fertilization
Apply balanced slow-release fertilizer once. Avoid high-nitrogen fertilizers which can promote foliage growth over flowering
Eggshell powder topdressing：Crush dried eggshells into fine powder; sprinkle 1 tbsp per plant around the base in early spring to boost soil calcium levelsPruning
- Prune back to 10–15 cm above soil in early spring to encourage bushy, compact growth
- Remove spent flower clusters to prolong the blooming period through early autumn
- Thin out crowded stems to improve air circulation and reduce fungal disease risk
Toxicity
Warning: this plant may be toxic.
Pets & Humans
Pets: ASPCA confirmed non-toxic to cats
Humans: No known toxic effects on humans
Garden Uses & Culture
Culture: N/A
Usage: Ornamental garden shrub; attracts pollinators like bees and butterflies
