For our area (Louisville) Is it better to keep a bougainvilea plant in a container or plant it in the ground?

We recently planted one, and initially it was full of blooms, but they have since dropped them all, but there is new plant (green leafy portion) on the plant.

They do best in containers...
The BOUGAINVILLEA is one of those plants that really doesn’t go by a common name, it is known by its botanical name.
It is a great tropical plant, a vine actually, native to Brazil. It makes a great plant for patios and decks in the summertime, but will not survive our winters in Kentuckiana, so it must be protected from freezing temperatures to survive.
The Bougainvillea has alternate leaves, and inconspicuous flowers, but the flowers are surrounded by papery, brightly colored bracts. The bracts range in color from bright purple to red to pink to copper, yellow and even white.
You can overwinter your Bougainvillea indoors near a bright east or south-facing window during the winter. Water it only when the soil surface dries out and give it a dilute solution of fertilizer once a month while it’s inside.
It will appreciate a little extra humidity indoors, so set the plant on a tray of pebbles and keep water in the pebbles—but not the pot bottom in the pebbles, you don’t want the pot to be sitting in water, this will cause root rot.
If your plant keeps actively growing, pinch back the growing tips to stimulate bushiness. If, on the other hand, it just limps along, don’t be too hard on yourself, it’s a lucky gardener that has just the right growing conditions indoors to stimulate good growth on a Bougainvillea.
Bougainvilleas may take a rest period between blooms, if your bougainvilleas blooms indoors in the winter, and then refuses to bloom when you put it back out for the summer, just give it some time, it will soon begin to respond to the heat and humidity of summer and start another bloom cycle. Just keep it well watered and fertilized.
If it looks so bad that you don’t want it inside the house anymore, you can cut it back and store it in an unheated garage or other sheltered spot where it won’t be exposed to freezing temperatures.
Be patient—it will perk back up when you put it back out on your deck next May. Cutting your Bougainvillea back is not exactly recommended when you bring it in during the fall of the year. It’s going to go through enough stress as it is. It’s better to cut it back in early summer to encourage lateral growth.
If you are able to successfully overwinter your Bougainvillea, start feeding it as soon as you put it back outside for the summer. Use a water-soluble fertilizer every other time you water, to stimulate new growth and flowers. Use a fertilizer that has higher levels of phosphorous and potassium than nitrogen to encourage good blooms.
Check the plant regularly and carefully for pests like spider mites on the undersides of the leaves, and treat as needed.