Blue Porterweed
Stachytarpheta cayennensis
Cayennensis
About this plant
Stachytarpheta cayennensis, commonly known as Blue Porterweed, is a flowering shrub known for its long spikes of small blue to purple flowers that attract butterflies and hummingbirds. It is often used in gardens for its ornamental value and ability to attract pollinators. The plant has a sprawling habit and can spread quickly in warm climates.
Taxonomy
- Genus
- Stachytarpheta
- Family
- Verbenaceae
- Higher classification
- Lamiales
- Plant type
- Shrub
- Lifespan
- Perennial
Origin & Distribution
- Native region
- Central America, South America
- Distribution
- Widely cultivated in tropical and subtropical regions worldwide, originally native to Central and South America.
Care
- Light preference
- Full sun
- Suitable locations
- Outdoor, Balcony, Greenhouse
- Preferred window facing
- South-facing, West-facing, East-facing
- Watering frequency
- Moderate
- Watering interval
- 3–7 days
- Humidity
- Normal
- Minimum
- 10 °C
- Maximum
- 35 °C
- Optimal
- 18–30 °C
- USDA hardiness zones
- 9–11
- Soil pH
- 6.0–7.5 (slightly acidic to neutral)
- Soil type
- well-draining loam or sandy soil
Watering. Water regularly during the growing season but allow the soil to dry out slightly between waterings. Reduce watering in cooler months.
Fertilizing. Feed the plant with a balanced, all-purpose fertilizer every 6 to 8 weeks during the growing season to encourage healthy growth and flowering.
Stachytarpheta cayennensis is a tough and fast-growing plant that thrives in sunny spots. It prefers well-draining soil and can tolerate dry conditions once established. It needs moderate watering and benefits from occasional pruning to keep it tidy.
Propagation
- Propagation methods
- Cuttings, Seeds
- Care difficulty
- Easy
Ornamental features
- Flowering
- Yes
- Flowering period
- spring–fall
Long spikes of blue-purple flowers, attractive to butterflies and hummingbirds; green foliage with a slightly sprawling form.
Toxicity & Safety
- Toxic to humans
- Non-toxic
- Toxic to pets
- Non-toxic
- Weed potential
- Potentially invasive
Non-toxic to humans and pets; safe to have around children and animals.
Allergy information
- Allergy risk
- Low
- Allergy triggers
- Skin contact
- Pollen level
- Low
This plant may cause mild skin irritation in some people who are sensitive. It does not produce much airborne pollen, so it is unlikely to cause pollen allergies. To reduce any risk, avoid direct skin contact if you have sensitive skin.
Common problems
Overwatering can cause root rot, and poor drainage may lead to fungal issues. In low light, the plant may become leggy and produce fewer flowers. Occasionally, pests like aphids or whiteflies may appear.
Uses
Primarily grown as an ornamental plant for gardens and landscapes; attracts pollinators like butterflies and hummingbirds.
Notes
Prune regularly to control its spread and encourage bushier growth. It can be invasive in some regions, so check local guidelines before planting outdoors. Repot young plants annually if grown in containers.