Bringing a Bougainvillea in for the Winter

Bougainvillea can be used in northern gardens if overwintered.

Bougainvillea, a tropical plant native to South America, blooms prolifically as an ornamental in North American gardens. In hardiness zone 9 and up, bougainvillea survives the winters outdoors. In northern climates, you'll need to protect your bougainvillea from killing frosts each winter. Preparation for bringing in your bougainvillea for the winter begins before the last frost. Overwintering requires an investment of time but has the advantage of saving you money by avoiding the cost of purchasing a bougainvillea again in the spring.

Things You'll Need

• Systemic pesticide
• Gravel
• Potting soil
• 3-gallon fiberglass or plastic flower pot
• Waterproof tray

Instructions

Preparation

1. Treat the plant with a systemic pesticide with the active ingredient of Imidacloprid one month before the first frost. Mix the systemic pesticide per package instructions and use this solution to drench the soil. Choose a time when the soil is dry to increase your plant's absorption of the pesticide and apply slowly to avoid runoff.

2. Prune the bougainvillea back to 1 foot by 1 foot two weeks before frost. Wear protective clothing to protect yourself from the thorns as you prune the plant and remove the pruned branches from your work area. Dig up the bougainvillea, keeping the root ball intact.

3. Fill the flower pot with an inch of gravel in the bottom of the pot, followed by an inch of potting soil. Place the bougainvillea in the pot, fill in around the roots with potting soil and water well to remove air pockets.

4. Leave your transplanted and pruned bougainvillea in the same place where it grew all summer to let it get acclimated to its new pot without environmental changes. Water well the first week after transplanting to minimize the shock and to encourage new root growth.

Moving the Plant

1. 

   Move the plant to a sunny window indoors

   Induce dormancy by placing your bougainvillea in a garage or basement where there is low natural sunlight and temperatures will remain between 30 to 50 degrees. Or place your bougainvillea in a sunny southern window and grow as a houseplant.

2. Place the waterproof tray down first, add a layer of gravel and add water to just below the level of the gravel. Keep the water in the tray replenished throughout the winter months to provide humidity for the plant. Mist your bougainvillea with a spray bottle if the forced heat from the furnace is drying the leaves.

3. Water your dormant bougainvillea just enough to keep it alive throughout the winter and do not fertilize. Treat again with the systemic pesticide if there are signs of pests.

Tips & Warnings

• Use potting soil without fertilizer.

References

• Bougainvillea Growers International: Hardiness Zone Tool
• National Gardening Association: Overwintering Bougainvillea
• The Washington Post: Diggingin: How to Overwinter Bougainvillea