Troubleshooting Pinguicula primuliflora Decline in Southern California

A grower near the Southern California coast reports Pinguicula primuliflora declining after a month: older leaves shriveling, new growth stunted, then dying. Other butterworts thrive. The plant was accidentally uprooted during unpacking but seemed fine initially. Conditions: original soil, RO water, SE windowsill with morning sun and bright indirect light, warm temperatures.

P. primuliflora

Diagnosis: Root Rot Susceptibility

P. primuliflora is notoriously prone to root rot, making moisture balance critical. The main plant may be unsalvageable, but a small "pup" (plantlet from a leaf) can be saved.

Improved Culture

• Soil: Use a more mineral-based mix (less peat).
• Pot size: Larger pots improve stability.
• Outdoor growing: In Southern California, grow outdoors year-round. UV light suppresses soil pathogens.
• Companion planting: Plant with taller Sarracenia for dappled sun (common in wild habitats).
• Live sphagnum: Has anti-fungal/bacterial properties.

Hardiness

These tolerate freezes to low 20s°F (-6°C), well beyond your coastal climate.

Reference

Video podcast on P. primuliflora care: YouTube link

Repot the pup in improved conditions for best results.