Troll-leaf Larkspur Plant Care
Delphinium trolliifolium A.Gray
Updated · Sources · How we source care data
Delphinium trolliifolium is a species of larkspur known by the common names poison delphinium, cow poison, and Columbian larkspur. It is native to Washington, Oregon, and northern California.
Every 7–10 days
Full sun to partial shade
50–75°F
40–60%
At a glance
How do you care for Troll-leaf Larkspur?
Water Troll-leaf Larkspur every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 50–75°F (10–24°C) and 40–60% humidity. Fertilize it every 6 months during the growing season. It is reported as toxic to pets, so keep it out of reach of pets.
Where Is the Troll-leaf Larkspur Native To?
What Is the Troll-leaf Larkspur?
Troll-leaf Larkspur (Delphinium trolliifolium) belongs to the Ranunculaceae family within the Delphinium genus. Troll-leaf Larkspur is native to Washington, Oregon, and northern California. Troll-leaf Larkspur is also known as Columbine-leaf Larkspur.
Troll-leaf Larkspur displays a tall spikes, clumping perennial growth habit, reaching up to 5 ft tall with a spread of approximately 2 ft. Troll-leaf Larkspur produces colorful, showy spikes of blue, purple, pink, or white flowers.
Leaf size: approximately 6 inches.
How Often Should You Water a Troll-leaf Larkspur?
Delphinium trolliifolium requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–10 days
Let soil partially dry between waterings
What Light Does the Troll-leaf Larkspur Need?
Troll-leaf Larkspur thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Troll-leaf Larkspur Prefer?
Delphinium trolliifolium grows best at temperatures of 50–75°F. Troll-leaf Larkspur prefers humidity levels of 40–60%.
Temperature
50–75°F
Humidity
40–60%
What Soil Mix Works Best for a Troll-leaf Larkspur?
Rich, well-draining soil with added compost for nutrients. Good drainage is essential for Troll-leaf Larkspur to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Troll-leaf Larkspur?
Feed Troll-leaf Larkspur every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Troll-leaf Larkspur?
Divide and replant every 3-4 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Troll-leaf Larkspur?
Troll-leaf Larkspur can be propagated through seeds, division of clumps. Similar propagation techniques also apply to delphinium plant care, which shares the same genus.
Is the Troll-leaf Larkspur Toxic to Pets and Children?
Toxic (caution)
Reported as toxic in our plant data. Not verified by the ASPCA.
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 Troll-leaf Larkspur?
Troll-leaf Larkspur is susceptible to aphids, slugs, snails. 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 Troll-leaf Larkspur Need?
Troll-leaf Larkspur grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Troll-leaf Larkspur is native to Washington, Oregon, and northern California. In cooler regions, grow Troll-leaf Larkspur as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Troll-leaf Larkspur 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 Delphinium genus — compare its care with other Delphinium species on PlantoScan.
Delphinium is part of the Ranunculaceae plant family — browse all Ranunculaceae genera and species.
Troll-leaf Larkspur thrives in bright light and direct sun — see other bright-light plants.
More Delphinium Species
Other Delphinium species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Delphinium trolliifolium A.Gray, family Ranunculaceae (first published in Proc. Amer. Acad. Arts 8: 275 (1872)) — World Flora Online record, IPNI name record.
- Pet toxicity: Troll-leaf Larkspur 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.
- 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.
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