Mentzelia memorabilis Plant Care

Mentzelia memorabilis N.H.Holmgren & P.K.Holmgren

Updated · Sources · How we source care data

Mentzelia memorabilis, the nine-eleven blazingstar, is a shrub-like perennial endemic to the Uinkaret Plateau in Mohave County Arizona and adjacent Washington County Utah. This is a species of conservation concern throughout its range.

Water

Every 7–10 days

Light

Full sun to partial shade

Temp

50–85°F

Humidity

30–60%

At a glance

How do you care for Mentzelia memorabilis?

Plant Mentzelia memorabilis 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.

Where Is the Mentzelia memorabilis Native To?

Native range1 country

What Is the Mentzelia memorabilis?

Mentzelia memorabilis (Mentzelia memorabilis) belongs to the Loasaceae family within the Mentzelia genus. Mentzelia memorabilis is native to the Uinkaret Plateau in Mohave County Arizona and adjacent Washington County Utah.

Mentzelia memorabilis displays an upright, branching growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Mentzelia memorabilis produces bright yellow, cup-shaped flowers.

Leaf size: approximately 3 inches.

How Often Should You Water a Mentzelia memorabilis?

Water a young or newly planted Mentzelia memorabilis 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 Mentzelia memorabilis Need?

Mentzelia memorabilis thrives in full sun to partial shade.

Light Requirement

Full sun to partial shade

What Temperature and Humidity Does the Mentzelia memorabilis Prefer?

Mentzelia memorabilis tolerates temperatures of 50–85°F. Mentzelia memorabilis prefers humidity levels of 30–60%.

Temperature

50–85°F

Humidity

30–60%

What Soil Mix Works Best for a Mentzelia memorabilis?

Well-draining sandy soil with some organic matter. Good drainage is essential for Mentzelia memorabilis to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Mentzelia memorabilis?

Feed Mentzelia memorabilis 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 Mentzelia memorabilis?

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

Mentzelia memorabilis 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 Mentzelia memorabilis?

Mentzelia memorabilis can spread to about 2 ft (0.5 m) and reach about 2 ft (1 m) tall. Space plants about 2 ft (0.5 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 Mentzelia memorabilis?

Prune Mentzelia memorabilis 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 Mentzelia memorabilis in Winter?

Mentzelia memorabilis 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 Mentzelia memorabilis?

Mentzelia memorabilis can be propagated through seeds. Similar propagation techniques also apply to showy stickleaf plant care, which shares the same genus.

Is the Mentzelia memorabilis Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Mentzelia memorabilis, 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 Mentzelia memorabilis?

Mentzelia memorabilis 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 Mentzelia memorabilis Need?

Mentzelia memorabilis grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Mentzelia memorabilis is native to the Uinkaret Plateau in Mohave County Arizona and adjacent Washington County Utah. In cooler regions, grow Mentzelia memorabilis as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 12a

Keep exploring plants

Mentzelia memorabilis 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 Mentzelia genus — compare its care with other Mentzelia species on PlantoScan.

Mentzelia is part of the Loasaceae plant family — browse all Loasaceae genera and species.

Mentzelia memorabilis thrives in bright light and direct sun — see other bright-light plants.

More Mentzelia Species

Other Mentzelia species in PlantoScan's care catalogue share similar watering, light, and soil preferences:

Sources

  • Scientific name & taxonomy: Mentzelia memorabilis N.H.Holmgren & P.K.Holmgren, family Loasaceae (first published in Syst. Bot. 27(4): 753 (2002).) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Mentzelia memorabilis, 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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