Thyme-leaved sandwort.

At a glance

Care level

Easy

Plant type

Annual herb

Light

Full sun

Indoor light

Direct sun

Water

Every 5 to 10 days

Mature size

6 inches

Growth rate

Fast

Hardiness

USDA 4 to 9

Bloom time

Late spring to mid summer

Care

Keep the soil on the drier side to mimic its natural sandy habitat. Watch for wilting if the soil stays too wet for too long. It thrives best when it gets plenty of sunshine throughout the day.

Watering

Water only when the top inch of soil feels dry to the touch.

Feeding

Apply a light balanced fertilizer once during the growing season if growth seems sluggish.

Pruning

Trim back spent flowers to encourage a tidy appearance and prevent unwanted self seeding.

Repotting

Since it is an annual, you likely will not need to repot it, but refresh the soil if keeping it in a container.

Soil

Sandy or rocky soil

Soil pH

Neutral to slightly alkaline

Temperature

-20 to 30°C

Humidity

40 to 70%

Safety

People

There are no reports of significant toxicity, but it is not intended for human consumption.

Children

While not toxic, the small size and delicate nature of the plant make it unsuitable for rough play.

Contact allergens

No specific contact irritants are known for this species.

Airborne allergens

The small amount of pollen produced is generally not considered a significant allergen.

Edibility

This plant is not considered edible and should not be consumed.

How to identify it

• Small oval shaped leaves
• Tiny white five petaled flowers
• Low growing mat forming habit
• Glandular hairy stems
• Capsule shaped seed pods

Height

0.05 to 0.2m

Spread

0.1 to 0.3m

Leaves

green, deciduous

Flowers

white, 0.5 to 1cm

Fruit

brown, Summer

Problems to watch for

• Root rot · Occurs when the soil stays too wet for too long.

Growing it

Propagation

seed

When to plant

spring, autumn

Pair this plant with other low-growing, drought-tolerant species to prevent it from being shaded out.

Grows well with

• Thyme · They share similar requirements for sun and well-draining soil.
• Sedum · These succulents provide a nice textural contrast in rock gardens.

Similar species

• Moss Sandwort · It has a similar growth habit but is a true perennial.

Science

Family

Caryophyllaceae

Genus

Arenaria

Order

Caryophyllales

Class

Magnoliopsida

Native range

Europe, temperate Asia, and North Africa, though it has naturalized widely elsewhere.

Conservation

It is a common and widespread species with no special conservation concerns.

It thrives in open, sandy, or gravelly habitats where it faces little competition from taller vegetation.

Value to wildlife

nectar source

Pollinators

bees, butterflies

Uses

rock gardens, ground cover, naturalizing in sandy areas

Taxonomy resolved against GBIF.

Questions people ask

Is this plant a perennial?

It is typically an annual or short-lived biennial.

Does it need full sun?

Yes, it performs best in full sun to light shade.

Where the name comes from

The genus name Arenaria comes from the Latin word arena, meaning sand, referring to its preferred habitat. The specific epithet serpyllifolia means thyme-leaved.

Good to know

• It is commonly known as thyme-leaved sandwort because its leaves resemble those of thyme.
• The plant often completes its entire life cycle in just a few months.
• It is highly adaptable to poor, rocky soils.