Coleus amboinicus
Coleus amboinicusUSDA | Grow Zone
10-12Outdoors all year in zones 10 to 12. Anywhere colder, keep it as a houseplant. Protect it below 50°F.
- Light
- Bright, indirect
- Water
- When top inch is dry
- Humidity
- 50-70%
- Temperature
- 65-80°F (18-27°C)
- Difficulty
- Beginner
- Growth
- Moderate
- Mature size
- 1-2 ft tall and wide
Coleus amboinicus, also known as Indian borage, is a versatile herb native to tropical regions. Known for its aromatic leaves and medicinal properties, it is a popular choice for both culinary and ornamental use.
Ask Vesper about Coleus amboinicus
Ideal temperature
65-80°F is where it grows fastest. Below 50°F cold damage starts.
Spacing and harvest
- Mature size
- 1-2 ft tall and wide
- Plant apart
- 12-24 in
- Frost
- Tender: no frost
Everything it needs
9 essentials at a glance
Watering
Coleus amboinicus prefers consistently moist soil but should not be waterlogged.
Water when the top inch of soil feels dry, typically every 1-2 weeks, adjusting frequency based on season and humidity. Signs of over-watering include yellowing leaves and root rot, while under-watering may cause wilting and leaf drop.
Light
This plant thrives in bright, indirect light but can tolerate partial shade.
Ideally, it should receive 4-6 hours of light daily, with some morning sun being beneficial. Too much direct sunlight can scorch the leaves, while too little light can lead to leggy growth.
Soil
Coleus amboinicus prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of potting soil, perlite, and compost is recommended to ensure good drainage and aeration. Avoid heavy soils that retain too much moisture.
Humidity
This plant enjoys higher humidity levels, ideally between 50-70%.
To increase humidity, consider misting the leaves, using a pebble tray with water, or placing a humidifier nearby. Signs of low humidity stress include browning leaf tips and edges.
Temperature
Coleus amboinicus thrives in temperatures between 65-80°F (18-27°C) and is not frost-tolerant.
It prefers USDA hardiness zones 10-12. Protect it from extreme heat and cold drafts, as temperatures below 50°F (10°C) can cause damage.
Fertilizing
Use a balanced liquid fertilizer with an NPK ratio of 10-10-10 every 4-6 weeks during the growing season.
Reduce feeding in fall and winter when growth slows. Signs of nutrient deficiency include yellowing leaves and poor growth.
Pruning
Prune Coleus amboinicus in early spring to encourage bushier growth and remove any dead or damaged leaves.
Use clean, sharp scissors or pruning shears. Regular pinching back of new growth can help maintain a compact shape and promote fuller foliage.
Repotting
Repot every 1-2 years or when the plant becomes root-bound, typically in spring.
Choose a pot that is 1-2 inches larger in diameter. Signs it needs repotting include roots growing out of the drainage holes and slowed growth. Carefully remove the plant from its pot, loosen the roots, and place it in fresh soil.
Propagation
Propagation can be done through stem cuttings, which should be taken in spring or summer.
Cut a healthy stem just below a node, remove the lower leaves, and place it in water or moist soil. Roots will develop in 2-4 weeks. Ensure the cutting has adequate light during this period.
When it's unhappy
Yellow leaves
Why it happens
Often caused by over-watering or insufficient light.
How to fix it
Adjust watering habits and ensure the plant receives adequate light.
Leggy growth
Why it happens
Occurs when the plant does not receive enough light.
How to fix it
Move the plant to a brighter location to encourage bushier growth.
Browning leaf tips
Why it happens
Usually a sign of low humidity or underwatering.
How to fix it
Increase humidity levels and adjust watering frequency.
Root rot
Why it happens
Caused by over-watering and poor drainage.
How to fix it
Ensure proper drainage and allow the soil to dry out between waterings.
Pest infestations (e.g., aphids, spider mites)
Why it happens
Commonly attracted to stressed plants.
How to fix it
Regularly inspect the plant and treat infestations with insecticidal soap or neem oil.
Care through the year
Spring
In spring, repot if necessary and resume regular feeding. Prune to encourage bushier growth and remove any dead leaves.
Summer
During summer, ensure consistent watering and monitor for pests. Increase humidity if temperatures rise significantly.
Fall
In fall, reduce watering and feeding as growth slows. Prepare the plant for cooler temperatures by moving it indoors if necessary.
Winter
In winter, keep the plant in a warm location away from drafts. Water less frequently, allowing the soil to dry out more between waterings.
Toxicity & Safety
Coleus amboinicus is generally considered non-toxic to pets and children. However, ingestion may cause mild stomach upset. Always monitor for any adverse reactions.
Good to know
Why are my Coleus amboinicus leaves turning yellow?
Yellowing leaves can indicate over-watering or insufficient light. Check the soil moisture and ensure the plant is receiving adequate light.
How often should I water my Coleus amboinicus?
Water when the top inch of soil feels dry, typically every 1-2 weeks. Adjust based on humidity and temperature conditions.
What is the ideal temperature for Coleus amboinicus?
This plant thrives in temperatures between 65-80°F (18-27°C) and should be protected from temperatures below 50°F (10°C).
How can I increase humidity for my Coleus amboinicus?
To increase humidity, mist the leaves, use a pebble tray with water, or place a humidifier nearby to create a more favorable environment.
When is the best time to prune Coleus amboinicus?
Prune in early spring to encourage bushier growth and remove any dead or damaged leaves. Regular pinching back can also help maintain shape.
Can I propagate Coleus amboinicus from cuttings?
Yes, stem cuttings can be taken in spring or summer. Place the cuttings in water or moist soil, and roots will develop in 2-4 weeks.
What type of soil is best for Coleus amboinicus?
A well-draining soil mix with a pH range of 6.0 to 7.0 is ideal. A combination of potting soil, perlite, and compost works well.
Track this plant in your garden.
Set care reminders, log growth, and join a community of plant lovers.