Smooth Rock Cress (Turritis glabra)

Photo: Chris StahlCC BY 4.0via iNaturalistresized / cropped

Smooth Rock Cress Plant Care

Turritis glabra L.

Updated · Sources · How we source care data

With its slender, lance-shaped leaves and tall spire of white flowers, this plant originates from Europe and western Asia. Plant collectors are drawn to Turritis glabra for its elegant appearance, adding vertical interest to gardens and attracting pollinators with its delicate blooms.

🌱Herbs
Water

Every 4–7 days

Light

Full sun to partial shade

Temp

50–75°F

Humidity

40–60%

At a glance

How do you care for Smooth Rock Cress?

Plant Smooth Rock Cress in full sun to partial shade (USDA zones 4a–8b) and water a young shrub every 4–7 days until it is established. It tolerates temperatures of 50–75°F (10–24°C). Fertilize it every 6 months during the growing season.

Where Is the Smooth Rock Cress Native To?

Native range45 countries

What Is the Smooth Rock Cress?

Smooth Rock Cress (Turritis glabra) belongs to the Brassicaceae family within the Turritis genus. Smooth Rock Cress is native to Europe, Asia, and North Africa, and. Smooth Rock Cress is also known as Tower Cress, Tower Rock Cress.

Smooth Rock Cress displays an upright, slender stem growth habit, reaching up to 1.5 ft tall with a spread of approximately 0.5 ft. Smooth Rock Cress produces small white or pink flowers in clusters.

Leaf size: approximately 2 inches.

How Often Should You Water a Smooth Rock Cress?

Water a young or newly planted Smooth Rock Cress every 4–7 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 4–7 days

Until established; then in dry spells

What Light Does the Smooth Rock Cress Need?

Smooth Rock Cress thrives in full sun to partial shade.

Light Requirement

Full sun to partial shade

What Temperature and Humidity Does the Smooth Rock Cress Prefer?

Turritis glabra tolerates temperatures of 50–75°F. Smooth Rock Cress prefers humidity levels of 40–60%.

Temperature

50–75°F

Humidity

40–60%

What Soil Mix Works Best for a Smooth Rock Cress?

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Smooth Rock Cress to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Smooth Rock Cress?

Feed Smooth Rock Cress 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 Smooth Rock Cress?

Choose a spot with full sun to partial shade and well-draining loamy soil with added compost for nutrients. Avoid low spots where water collects after rain.

Smooth Rock Cress is suited to USDA Zone 4a – 8b.

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 Smooth Rock Cress?

Smooth Rock Cress can spread to about 1 ft (0.2 m) and reach about 2 ft (0 m) tall. Space plants about 1 ft (0.2 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 Smooth Rock Cress?

Prune Smooth Rock Cress 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 Smooth Rock Cress in Winter?

Smooth Rock Cress is hardy down to USDA zone 4a, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.

How Do You Propagate a Smooth Rock Cress?

Smooth Rock Cress can be propagated through seeds. Similar propagation techniques also apply to tower mustard plant care, which shares the same genus.

Is the Smooth Rock Cress Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Smooth Rock Cress, 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 Smooth Rock Cress?

Smooth Rock Cress is susceptible to aphids, cabbage worms, flea beetles. 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 Smooth Rock Cress Need?

Smooth Rock Cress grows outdoors in USDA Zone 4a – 8b. It survives winters down to planting zone 4a. Smooth Rock Cress is native to Europe, Asia, and North Africa, and.

Hardiness Zone

Zone 4a – 8b

Keep exploring plants

Smooth Rock Cress 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 Turritis genus — compare its care with other Turritis species on PlantoScan.

Turritis is part of the Brassicaceae plant family — browse all Brassicaceae genera and species.

Smooth Rock Cress 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: Turritis glabra L., family Brassicaceae (first published in Sp. Pl. : 666 (1753)) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Smooth Rock Cress, 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.
  • Photo: Chris Stahl, CC BY 4.0, iNaturalist — original.
  • Hardiness zone: USDA Zone 4a – 8b, estimated from the plant's typical growing conditions.
  • 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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