Obconic Holocarpha Plant Care

Holocarpha obconica (J.C.Clausen & D.D.Keck) D.D.Keck

Updated · Sources · How we source care data

Holocarpha obconica, commonly known as the San Joaquin tarweed, is a North American plant species in the sunflower family. It is endemic to California, primarily in the Central Valley and adjacent regions.

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Water

Every 7–10 days

Light

Full sun to partial shade

Temp

50–80°F

Humidity

40–60%

At a glance

How do you care for Obconic Holocarpha?

Plant Obconic Holocarpha 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 Obconic Holocarpha Native To?

Native range1 country

What Is the Obconic Holocarpha?

Obconic Holocarpha (Holocarpha obconica) belongs to the Asteraceae family within the Holocarpha genus. Obconic Holocarpha is native to California, primarily in the Central Valley and adjacent regions.

Obconic Holocarpha displays a low spreading groundcover growth habit, reaching up to 0.5 ft tall with a spread of approximately 2 ft. Obconic Holocarpha produces small white or yellow daisy-like flowers in clusters.

Leaf size: approximately 2 inches.

How Often Should You Water a Obconic Holocarpha?

Water a young or newly planted Obconic Holocarpha 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 Obconic Holocarpha Need?

Obconic Holocarpha thrives in full sun to partial shade.

Light Requirement

Full sun to partial shade

What Temperature and Humidity Does the Obconic Holocarpha Prefer?

Holocarpha obconica tolerates temperatures of 50–80°F. Obconic Holocarpha prefers humidity levels of 40–60%.

Temperature

50–80°F

Humidity

40–60%

What Soil Mix Works Best for a Obconic Holocarpha?

Well-draining sandy soil mix with added organic matter. Good drainage is essential for Obconic Holocarpha to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Obconic Holocarpha?

Feed Obconic Holocarpha 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 Obconic Holocarpha?

Choose a spot with full sun to partial shade and well-draining sandy soil mix with added organic matter. Avoid low spots where water collects after rain.

Obconic Holocarpha 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 Obconic Holocarpha?

Obconic Holocarpha can spread to about 2 ft (0.6 m) and reach about 1 ft (0 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 Obconic Holocarpha?

Prune Obconic Holocarpha 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 Obconic Holocarpha in Winter?

Obconic Holocarpha 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 Obconic Holocarpha?

Obconic Holocarpha can be propagated through seeds, division of root ball. Similar propagation techniques also apply to heermann's tarweed plant care, which shares the same genus.

Is the Obconic Holocarpha Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Obconic Holocarpha, 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 Obconic Holocarpha?

Obconic Holocarpha is susceptible to aphids, whiteflies, spider mites. 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 Obconic Holocarpha Need?

Obconic Holocarpha grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Obconic Holocarpha is native to California, primarily in the Central Valley and adjacent regions. In cooler regions, grow Obconic Holocarpha as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 12a

Keep exploring plants

Obconic Holocarpha 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 Holocarpha genus — compare its care with other Holocarpha species on PlantoScan.

Holocarpha is part of the Asteraceae plant family — browse all Asteraceae genera and species.

Obconic Holocarpha thrives in bright light and direct sun — see other bright-light plants.

Related Plant Care Guides

Closely related plants with similar care requirements:

Sources

  • Scientific name & taxonomy: Holocarpha obconica (J.C.Clausen & D.D.Keck) D.D.Keck, family Asteraceae (first published in Aliso 4: 111 (1958)) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Obconic Holocarpha, 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.

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