
Photo: (of code) -xfi-CC BY-SA 3.0via Wikimedia Commonsresized / cropped
Small White Snakeroot Plant Care
Ageratina paupercula (A.Gray) R.M.King & H.Rob.
Updated · Sources · How we source care data
Ageratina paupercula, called the Santa Rita snakeroot, is a North American species of shrubs or perennial herbs in the family Asteraceae. It is found only in the states of Arizona, Sonora, Chihuahua, Durango, Nayarit, and Jalisco.
Every 7–10 days
Full sun to partial shade
50–85°F
40–70%
At a glance
How do you care for Small White Snakeroot?
Plant Small White Snakeroot in full sun to partial shade (USDA zones 12a) and water a young shrub every 7–10 days until it is established. It tolerates temperatures of 50–85°F (10–29°C). Fertilize it every 6 months during the growing season. It is reported as toxic to pets, so keep it out of reach of pets.
What Is the Small White Snakeroot?
Small White Snakeroot (Ageratina paupercula) belongs to the Asteraceae family within the Ageratina genus. Small White Snakeroot is also known as Eupatorium pauperculum, Kyrstenia paupercula, Piptothrix arizonica.
Small White Snakeroot displays an upright, bushy shrub growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Small White Snakeroot produces clusters of small white or pink flowers in flat-topped inflorescences.
Leaf size: approximately 4 inches.
How Often Should You Water a Small White Snakeroot?
Water a young or newly planted Small White Snakeroot every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–10 days
Until established; then in dry spells
What Light Does the Small White Snakeroot Need?
Small White Snakeroot thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Small White Snakeroot Prefer?
Ageratina paupercula tolerates temperatures of 50–85°F. Small White Snakeroot prefers humidity levels of 40–70%.
Temperature
50–85°F
Humidity
40–70%
What Soil Mix Works Best for a Small White Snakeroot?
Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for Small White Snakeroot to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Small White Snakeroot?
Feed Small White Snakeroot every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Small White Snakeroot?
Choose a spot with full sun to partial shade and well-draining loamy soil with added organic matter for moisture retention. Avoid low spots where water collects after rain.
Small White Snakeroot is suited to USDA Zone 12a.
Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Small White Snakeroot?
Small White Snakeroot can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the plant spacing calculator.
How Do You Prune a Small White Snakeroot?
Prune Small White Snakeroot while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.
How Do You Care for a Small White Snakeroot in Winter?
Small White Snakeroot is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.
How Do You Propagate a Small White Snakeroot?
Small White Snakeroot can be propagated through seeds, division of root ball. Similar propagation techniques also apply to sticky ageratina plant care, which shares the same genus.
Is the Small White Snakeroot Toxic to Pets and Children?
Toxic (caution)
Reported as toxic in our plant data. Not verified by the ASPCA.
Toxic to humans and pets if ingested
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Small White Snakeroot?
Small White Snakeroot is susceptible to aphids, spider mites, whiteflies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Small White Snakeroot Need?
Small White Snakeroot grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. In cooler regions, grow Small White Snakeroot as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Small White Snakeroot is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Ageratina genus — compare its care with other Ageratina species on PlantoScan.
Ageratina is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Small White Snakeroot thrives in bright light and direct sun — see other bright-light plants.
More Ageratina Species
Other Ageratina species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Ageratina paupercula (A.Gray) R.M.King & H.Rob., family Asteraceae (first published in Phytologia 19: 215 (1970)) — World Flora Online record, IPNI name record.
- Pet toxicity: Small White Snakeroot is reported as toxic to pets in our plant data (not verified by the ASPCA), so treat it with caution. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: (of code) -xfi-, CC BY-SA 3.0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 12a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
