How to Grow Chromolaena Odorata | Siam Weed Information

Last Updated: 19.10.2023

Chromolaena odorata has many pharmacological uses, so it makes a lot of sense to grow it! Here are all the details on Siam Weed.

Chromolaena odorata

Commonly known as Siam Weed or triffid weed, Chromolaena odorata is a perennial herbaceous plant belonging to the Asteraceae family. Here’s all about how to grow it along with all the details!

Chromolaena Odorata Information

Chromolaena odorata, also popular as Christmas bush, or devil weed,  is native to the tropical regions of Central and South America. However, due to its invasive nature, it has spread to many parts of the world, including Africa, Asia, and the Pacific Islands.

The plant can grow up to 3 meters (10 feet) tall and has a woody stem with numerous branches. The leaves are oval-shaped and have serrated edges. They are typically 7-20 centimeters long and have a rough texture. The flowers of Chromolaena odorata are small and usually white or lavender in color, arranged in clusters at the end of the branches.

The plant is considered one of the world’s most invasive weed species. It can quickly colonize disturbed areas, such as agricultural lands, forests, and roadsides, outcompeting native vegetation and reducing biodiversity. Its ability to reproduce through seeds, as well as stem and root fragments, contributes to its invasive nature.

Check Out How to Grow Caesalpinia Pulcherrima here!

How to Grow Chromolaena Odorata?


Growing Chromolaena odorata from seeds can be a good experience!

  • Obtain seeds of Chromolaena odorata from mature plants. Look for seed heads or clusters that have turned brown and dried on the plant. Collect the seeds by gently shaking or rubbing the seed heads to release the mature seeds.
  • Fill seed trays or pots with the seed-starting mix. Place the seeds on the surface and lightly press them into the soil. Do not cover the seeds with different soil; they require light to germinate.
  • Chromolaena odorata seeds can germinate for several weeks to months, and the germination rate may be variable. Maintain a warm and humid environment for the seeds by covering the trays or pots with a clear plastic cover or placing them in a plastic bag. Keep them in a location with temperatures between 21°C and 29°C.
  • Once the Siam Weed seedlings have emerged and have developed a few sets of true leaves, they can be transplanted into individual pots or a prepared garden bed. Choose a location that receives full sun to partial shade.

Check Out How to Grow Salvia Splendens here!

Requirements to Grow Chromolaena Odorata

Chromolaena odorata 2


Chromolaena odorata prefers full sun to partial shade. It thrives in bright light conditions but can tolerate some shade. Aim to provide at least 4-6 hours of direct sunlight daily for optimal growth.


The plant can grow in various soil types but prefers well-draining soils. Siam Weed can tolerate sandy, loamy, or clayey soils. However, it is adaptable and can grow in poor soils as well. The pH level of the soil should be around neutral (pH 6.0-7.5).

Check Out How to Identify Giloy Plant here!


Chromolaena odorata has moderate water needs. Water Siam Weed regularly, keeping the soil consistently moist but not soggy. Avoid overwatering, as it can lead to root rot. As the plant is a weed, it is pretty much drought tolerant.


Siam Weed thrives in tropical and subtropical regions and will grow fine in temperatures between 21°C and 36°C.

Chromolaena Odorata Care


Chromolaena odorata is adaptable and can grow in nutrient-poor soils. However, you can apply a balanced slow-release fertilizer during the growing season to encourage vigorous growth.

Avoid excessive fertilization, which may lead to excessive growth and make the plant more invasive.


Pruning Chromolaena odorata is essential to control its growth and prevent it from becoming invasive. Regularly trim back the plant to maintain its size and shape. Remove any dead, damaged, or diseased stems or leaves.

Pruning can be done throughout the year, but it is best to avoid severe pruning during periods of high stress, such as extreme heat or cold.

Pests and Diseases

Chromolaena odorata is relatively resistant to pests and diseases. However, Siam Weed can occasionally be attacked by aphids, whiteflies, or caterpillars.

Monitor the plant regularly and take appropriate action if you notice an infestation. Regarding diseases, root rot can occur in poorly drained soils or with overwatering. Maintain good drainage and avoid waterlogged conditions to prevent this.

Check Out How to Grow Foxtail Palm Easily here!

Chromolaena Odorata Uses

  1. Traditional Medicine: Extracts from the plant is good for treating skin conditions like wounds, rashes, and insect bites. It also has antimicrobial and anti-inflammatory properties.
  2. Soil Improvement: It has the ability to improve soil fertility due to its nitrogen-fixing capabilities. The plant can capture atmospheric nitrogen and convert it into a form that other plants can use. Therefore, it is sometimes used as a green manure crop or for soil reclamation.
  3. Livestock Feed: While Chromolaena odorata is an invasive weed, it can be a great livestock feed, particularly for cattle and goats. The leaves are rich in protein and can serve as a forage source.

It’s worth noting that despite some potential uses, the negative ecological impact of Chromolaena odorata as an invasive species outweighs its benefits.

Leave a Comment

Send this to a friend