In Thailand, they often grow up to 20 foot when planted in the ground.
Due to their height, they are often used to accentuate other low level bedded plants, which they tower above. Their tall appearence in a natural tropical setting makes them very striking in the correct light.
Not native to Thailand, the Dracaena Fragrans (or commonly known 'Dragon Plant') originates in West Africa, Tanzania and Zambia. Due to its fragrent white flowers, this is where the 'fragrans' part of its name comes from.
The Dracaena is also a popular house plant, and it's growth is limited when potted.