Answer: Bougainvillea can adapt to growing in containers but they do not like to have their roots disturbed so that may explain why the plant is not flourishing. If you'd like to start all over with a new plant, choose a container that will accommodate the roots for a very long time. A 10-15 gallon container should work. Bougainvilleas bloom best when they're slightly rootbound. Fill the container with a half and half mixture of garden soil and potting soil for best drainage, then water and feed on a regular basis. These vines are heavy feeders and respond best to feeding every week or two with ? strength water soluble fertilizer, e.g., Peter's 20-20-20, Excel 21-5-20, Miracle Grow or Rapid Grow. With high light and consistent feeding, the plants will bloom at least 11 months of the year. Straight hibiscus food has also been a very successful fertilizer.
Bougainvillea flower best under stress. Keep the plant slightly on the dry side, and allow the plant to become root bound. In containers they should be watered frequently so the soil feels nicely moist but never soggy. Water thoroughly, then allow to become moderately dry between waterings. They respond extremely well to stress, such as drought and heat, and reward you with excellent bloom. Even with a tolerance for drought, however, you end up watering plants nearly every day because of the small root system. Irrigate enough at each watering so that the water comes through the drain holes in the bottom of the container.
Keep in mind that containers in full sunshine can absorb too much heat, essentially cooking the roots. If the site is on a concrete patio, you might want to place the planted container into a larger decorative container and stuff some insulating material between the two containers. This will protect the roots from overheating.
The blooms on bougainvilleas are not true flowers, but are 3 large papery bracts that encircle small, white, tubular inconspicuous flowers. Some of the best bougainvilleas to look for are: white and lavender 'Dr. Barry', and its gold and green leaved variegated form 'Vickie'; the dark pink flowers of 'Juanita Hatten', and its new mutation with green leaves spatter painted with gold; 'Barbara Karst' with bright red to bluish crimson flowers in sun or shade, blooms very young, likes heat; 'Sundown' Apricot color, vigorous, good bloomer, heavy feeder. 'Hawaiian Torch' fuchsia, with compact bloom arranged around a spike. 'Texas Dawn' smaller pink flowers, in huge clusters, vigorous, keep cut back. 'Double Pink' clear pink, vigorous, keep trimmed back, spent flowers must be cut off since double flowering types will not shed flowers in the typical fashion. 'Surprise' large, clear pink-white bi-color flowers, easy bloomer. Excellent! 'Royal Purple' the most striking purple flowers on the market.
Best wishes with your bougainvilleas!
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