Overwintering Bougainvillea in Cool Coastal Climates: Mulching and Indoor Alternatives

Bougainvillea on Whidbey Island (Zone 8a‑8b)

Your winters (30‑40°F) are too cold for bougainvillea to survive unprotected outdoors.

Outdoor Mulching Method

• Cut the plant back to about 12 inches.
• Apply a thick mulch layer (straw, leaves, pine needles) over the crown.
• On days above freezing, pull mulch back to let the soil warm; replace at night.

Indoor Alternative

Pot the plant and keep it in a bright, cool room (50‑60°F). Water sparingly. It will not thrive indoors but may survive until spring.

Bougainvillea doesn't go fully dormant, so some growth may occur during warm spells—this is normal.