Oxalis stricta: The Bane of Succulent Collections

Many Oxalis species are lovely garden plants, but Oxalis stricta (common yellow woodsorrel) is a relentless weed—especially in cactus and succulent pots. It appears everywhere, spreads aggressively, and resists eradication.

Oxalis triangularis 'Atropurpurea'—a chosen ornamental, not a weed.

Oxalis gigantea—a succulent species, not a weed (to me).

Oxalis 'Sunshine Velvet'—chosen ornamental, but reverts to green in shade, resembling O. stricta.

Why It's a Nightmare

• Reproduction: Seeds (100s per pod, explode 4 ft), rhizomes/stolons (fragile, snap leaving regenerative fragments), root regrowth.
• Germination: Only needs oxygen—ubiquitous.
• In pots: Grows tenaciously in dry, lean soil. Winds around cactus spines, making removal painful/impossible. Traps moisture → rot risk. Dense infestations outcompete succulents for water/nutrients.

Even nibbled, it thrives.

Simple root, stolon connections, seed pods.

Seed pods explode, scattering tiny red-brown seeds.

Control Attempts & Failures

• Avoidance: Impossible—all pots eventually infested.
• Roundup (glyphosate): Kills individual plants but also kills many succulents (they absorb through "skin"). Risky, not a long-term solution.
• Specialty herbicides (Oxalis X / ammonium thiosulfate, emergent toxins): Hard to find; untested on rare succulents.
• Mulching (black plastic/newspaper): Blocks light/oxygen—works in beds but rots succulents. Rock/sand top dressing doesn't deter it.
• Tweezers/forceps: Tedious, painful on spiny plants, temporary—seeds reinfest from neighbors.
• Repotting (bare-root, wash soil): Effective but time-consuming, disrupts staging, impractical for large/spiny collections. Reinfestation within a year.
• Desiccation: Withholding water 6–12 months kills O. stricta (many succulents tolerate it). But one watering brings it back.

Oxalis entwined with cacti—removal is a nightmare.

Roots exposed after pot removal.

Clinging, wedged, smothering.

Herbicide options tried and considered.

Emergent toxins—might be succulent-safe? Untested.

Thriving in stone mulch.

Forceps used; temporarily cleared but returns.

Before and ~30 min after tweezing—sigh.

Bare-root cleaning—the most thorough but disruptive method.

Good candidate for desiccation treatment.

The Reality

No ultimate solution exists without full-time hired help. Current strategy: rip off visible growth, ignore the rest, accept a "moderately tidy" look. Oxalis stricta wins.