Conyza canadensis
Canadian horseweed · Horseweed · Prideweed · Canada Fleabane · Mares tail
Description
Source: leafsnapConyza canadensis, commonly known as Canadian horseweed or mare's tail, is a herbaceous annual plant in the Asteraceae family. Native to North America, it has now spread to other parts of the world. The plant can grow up to 2 meters tall, featuring a slender stem with numerous branches that bear small white or pinkish flowers. Canadian horseweed thrives in disturbed areas such as roadsides, fields, and waste places. It can grow in a wide range of soil types and tolerate both wet and dry conditions. The plant reproduces via seeds that are dispersed by the wind. The leaves of Conyza canadensis are alternate, lance-shaped, and have serrated edges covered in fine hairs. When crushed, the leaves emit a distinctive odor often described as pungent or unpleasant. For centuries, Native Americans have used the plant for medicinal purposes, believing it had anti-inflammatory properties useful for treating respiratory ailments such as asthma and bronchitis. However, Canadian horseweed is now considered an invasive species in many parts of the world. It competes with native plants for resources like water and nutrients, and its rapid growth rate makes it difficult to control once established. In summary, Conyza canadensis is an annual herbaceous plant with small white or pinkish flowers that thrives in disturbed areas. It reproduces through seeds dispersed by the wind, has alternate lance-shaped leaves with serrated edges covered in fine hairs, and was historically used by Native Americans for its medicinal properties. However, due to its invasive nature and rapid growth, it outcompetes native plants and is challenging to control once established.
🌳 Horseweed is more than just a weed; it is a source of natural dye valued for its strong color. The plant contains essential oils that are sought for use in aromatherapy. Notably, horseweed also acts as a bioindicator, revealing high metal concentrations in soil and thus playing an important role in evaluating soil health.
🎭 Holiness, cleansing, banishing the unwanted
Care Guide
💧 Water Every 3 days
It prefers dry or moist soil and can tolerate drought. It has good resistance to summer drought, although some of the lower leaves may turn yellow and wither away.
☀️ Light Full sun
Horseweed strongly prefers abundant sunlight to grow well. Its development is greatly aided by the sun's radiant energy. Nevertheless, it is hardy enough to establish in places with moderately reduced light. In its natural range it is frequently found in spots receiving plenty of sun. Extremely low or excessively high light levels can impair its normal growth.
🌡️ Temperature 0–35°C
Horseweed is native to regions with mild climates and thrives best at temperatures between 68 and 95 °F (20 and 35 °C). Seasonal temperature adjustments may be required to reproduce these conditions.
💨 Humidity dry (<40%)
This plant prefers dry conditions, so don't mist it. However, watering it less often can also thrive in higher humidity.
🪴 Soil 6-7
🌱 Fertilizer
Horseweed responds well to regular, light fertilizer applications to encourage healthy leaf development. You should apply fertilizer roughly once a month during the summer. Nitrogen is vital for the foliage, and adding nitrogen-rich sources supports Horseweed's growth.
🪴 Pot & Repot
✂️ Pruning
🌿 Propagating
🐛 Diseases & pets
☠️ Toxicity
These plants contain cardiac glycosides, and they are the most common toxin affecting cardiovascular health. Generally, all parts of the plant are highly toxic and lethal if eaten in small quantities.
Characteristics
- Plant Type
- Herb
- Life Cycle
- Annual, Biennial
- Genus
- Conyza
- Family
- Asteraceae
- Hardiness Zone
- 3-10
- Mature Height
- 0.49 m to 1.52 m
- Mature Spread
- 49 cm
- Leaf Color
- Green
- Leaf Type
- Deciduous
- Flower Color
- White
- Flower Size
- 1.02 cm
- Bloom Time
- Early summer, Mid summer
- Planting Time
- Spring, Summer, Autumn, Winter
- Harvest Time
- Mid summer
- Native Area
- Colombia, Bahamas, Belize, Honduras, Mexico, Guatemala, Bolivia, Venezuela, Peru, El Salvador, Nicaragua, Ecuador, Costa Rica, Panama, Jamaica, China