Plumbago auriculata: Beautiful but Not Cold-Hardy for Pennsylvania Gardens

Know Your Zone Before Planting

Cape plumbago (Plumbago auriculata) is a stunning, blue-flowered shrub native to South Africa. While it thrives in Zones 8b–11, it cannot survive Pennsylvania winters (Zone 6) outdoors.

Key Facts

• Hardiness: Only to about 15–20°F (Zone 8b).
• Growth habit: 4–6 ft tall and wide, not a ground cover.
• Flowers: Bright blue, five-petaled clusters from spring to frost.

Options for Northern Gardeners

• Grow in large containers and overwinter indoors in a cool, bright location (40–50°F).
• Treat as an annual, replacing each spring.
• Consider hardy alternatives like Ceratostigma plumbaginoides (hardy plumbago, Zone 5), a low-growing perennial with similar blue flowers.

If you've already purchased tender plumbago, returning it is wise unless you can provide winter protection.