perennial

Stiff Twinspur

The Story

Plant Bio

Diascia rigescens, the stiff twinspur, is a semi-evergreen perennial forming a low, spreading mat of branching, four-angled stems. The foliage consists of thick-textured, heart-shaped leaves with sharply serrated margins, which remain dense at the base of the plant.

The species is distinguished by its upright terminal racemes of pink to salmon flowers, each featuring two prominent downward-pointing spurs. Unlike many trailing diascias, this species maintains a more rigid, clumping structure that can sprawl over rock walls or banks.

Uses & Benefits:

Produces dense, colorful spikes of pink flowers that cascade over walls, containers, or garden borders.

Functions as an effective, fast-growing groundcover or container filler that suppresses weeds once established.

Attracts bees, generalist insect pollinators, and hummingbirds with its nectar-rich, spurred flowers.

Essentials

At a Glance

Plant Type

Perennial

Height

12"

Width

18"

Light

Full Sun, Partial Sun

Zones

8, 9, 10

Water

Moderate

Humidity

Moderate to Low

Lifespan

Short-lived Perennial

Native To

Southern Africa

Toxicity

Non-toxic

Bloom period

Summer – Fall

In flower about 6 months of the year

Planting

How to Grow

Select a planting site with full sun and exceptionally well-drained, sandy or loamy soil.
Space plants 12 to 18 inches apart to allow the trailing stems room to spread into a dense mat.
Water regularly during the active growing season, keeping the soil consistently moist but never waterlogged.
Apply a balanced liquid fertilizer every two weeks during summer if growing in containers to sustain flower production.

Pro Tip

Prune back the stems by half immediately after the first summer bloom flush declines; this stimulates fresh basal nodes to produce a robust second crop of flowers in the fall.

Keep It Thriving

Care Guide

Do

Deadhead spent flower spikes regularly to encourage continuous blooming.
Ensure sharp drainage in winter to prevent root and crown rot.
Shear the plant back by one-third to one-half if it becomes straggly in mid-summer.

Don't

Do not prune heavily into old, leafless, woody base stems as they fail to regenerate.
Do not allow the soil to remain waterlogged, especially during cold winter months.
Do not plant in heavy, poorly drained clay soils.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Fertilize
Propagate
Prune
Winter Prep

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Rock gardensContainer plantingsBorder edgingSprawling over retaining wallsCottage gardens

Companion Plants

Salvia Penstemon Nepeta Festuca glauca

Multiply

Propagation Methods

Good to Know

Common Questions

Stiff Twinspur questions

What zones can Stiff Twinspur grow in?

Stiff Twinspur is hardy in USDA Zones 8–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does Stiff Twinspur bloom?

Stiff Twinspur typically blooms in summer through fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Stiff Twinspur need full sun?

Stiff Twinspur does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.