My Bougainvillea has Flowers, but the leaves are falling off. Any idea why?
It could be losing leaves due to normal seasonal changes or due to excessively wet roots because of overwatering, too much rain, or poorly drained soil. See this article for more possibilities:
https://www.gardeningknowhow.com/garden-how-to/info/plant-dropping-leaves.htm
I have a bougainvillea that is suppose to be a trellis type. My problem is that I want it to only be three feet tall. How do I keep it at this height and have continuous blooms? I have read articles that say continuous cutting causes more leaves and thorns rather then blooms.
This would be true. If you have a trellis type plant, then you are at the mercy of nature. You will have to find a variety that is, genetically, short. Continuous pruning may prevent any future blooms.
This article will refresh you on the care of these: https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/pruning-bougainvilleas.htm
Will bougainvillea work as a 2' tall groundcover or will it become too bulky? Thanks!
Bougainvillea makes a lovely statement as a climbing plant and even a cascading shrub. It may not be a good choice as a ground cover.
https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/bougainvillea-garden-care.htm
https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/bougainvillea-pruning.htm
My plants were taken inside for winter and is growing a long branch with no flowers. One has a lot of blooms. What should I do? Cut the long branch down?
It is probably fine to cut back the long branch. This may be a reaction to the lower light in the house, so exposing that plant to more light might help.
My bougy flowers but its limbs aren't growing. It has stayed compact thru the 2016 growing season. Does it need nitrogen fertilizer to get it to grow?
Yes, nitrogen fertilizer (or any balanced fertilizer) is probably just what your plant needs. You can use compost or conventional fertilizer as described here:
https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/bougainvillea-garden-care.htm
http://www.greenthumbnsy.com/bedding_plants/bougainvillea_growing_guide
See attached pictures and tell me what I need to do. Does it need more water.
The soil does seem a bit dry. You may want to repot as well. It could be getting rootbound. Add fertilizer, dolomitic lime, and wettable sulfur to the soil to condition it and keep it happy. Here is an article for more information on the care of these: https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/bougainvillea-garden-care.htm
When do you start pruning Bougainvilleas ? Should I prune to new wood ? Thank you
Early spring is best for pruning.
This article will help you though the process.
https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/pruning-bougainvilleas.htm