Broadlobe Phacelia Plant Care
Phacelia platyloba A.Gray
Updated · Sources · How we source care data
Phacelia platyloba is a species of phacelia known by the common name broadlobe phacelia. It is endemic to California, where it is known only from a section of the central Sierra Nevada foothills.
Every 7–10 days
Full sun to partial shade
50–80°F
40–60%
At a glance
How do you care for Broadlobe Phacelia?
Plant Broadlobe Phacelia 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 50–80°F (10–27°C). Fertilize it every 6 months during the growing season.
Where Is the Broadlobe Phacelia Native To?
What Is the Broadlobe Phacelia?
Broadlobe Phacelia (Phacelia platyloba) belongs to the Boraginaceae family within the Phacelia genus. Broadlobe Phacelia is native to California.
Broadlobe Phacelia displays a low rosette, spreading growth habit, reaching up to 1.5 ft tall with a spread of approximately 1 ft. Broadlobe Phacelia produces small, bell-shaped flowers in shades of blue, purple, or white.
Leaf size: approximately 2 inches.
How Often Should You Water a Broadlobe Phacelia?
Water a young or newly planted Broadlobe Phacelia 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 Broadlobe Phacelia Need?
Broadlobe Phacelia thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Broadlobe Phacelia Prefer?
Phacelia platyloba tolerates temperatures of 50–80°F. Broadlobe Phacelia prefers humidity levels of 40–60%.
Temperature
50–80°F
Humidity
40–60%
What Soil Mix Works Best for a Broadlobe Phacelia?
Well-draining sandy loam with added organic matter. Good drainage is essential for Broadlobe Phacelia to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Broadlobe Phacelia?
Feed Broadlobe Phacelia 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 Broadlobe Phacelia?
Choose a spot with full sun to partial shade and well-draining sandy loam with added organic matter. Avoid low spots where water collects after rain.
Broadlobe Phacelia 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 Broadlobe Phacelia?
Broadlobe Phacelia can spread to about 1 ft (0.3 m) and reach about 2 ft (0 m) tall. Space plants about 1 ft (0.3 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 Broadlobe Phacelia?
Prune Broadlobe Phacelia 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 Broadlobe Phacelia in Winter?
Broadlobe Phacelia 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 Broadlobe Phacelia?
Broadlobe Phacelia can be propagated through seeds. Similar propagation techniques also apply to phacelia adenophora plant care, which shares the same genus.
Is the Broadlobe Phacelia Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Broadlobe Phacelia, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
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 Broadlobe Phacelia?
Broadlobe Phacelia is susceptible to aphids, spider mites, thrips. 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 Broadlobe Phacelia Need?
Broadlobe Phacelia grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Broadlobe Phacelia is native to California. In cooler regions, grow Broadlobe Phacelia as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Broadlobe Phacelia 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 Phacelia genus — compare its care with other Phacelia species on PlantoScan.
Phacelia is part of the Boraginaceae plant family — browse all Boraginaceae genera and species.
Broadlobe Phacelia thrives in bright light and direct sun — see other bright-light plants.
More Phacelia Species
Other Phacelia species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Phacelia platyloba A.Gray, family Boraginaceae (first published in Proc. Amer. Acad. Arts 17: 223 (1882)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Broadlobe Phacelia, so we can't confirm whether it is safe for cats and dogs. 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.
