Characteristic of the colonial garden is its close relationship to the cottage-garden. The style has been developped at the eastern coast of the U.S. about a hundred years ago. Abundance and comfort are its main components, next to be in harmony with its surroundings.
But the colonial garden is somehow more 'formal' than the cottage-garden. (Rose-)arches, small hedges and arbours are commonly applied style-elements. Despite of that the atmosphere is unconstrained and playful. A lot of natural materials are used like flagstone or gravel for the garden-walks, wooden garden-furniture, stone-vases, wooden rain-butts, italian pottery, etc.
The planting is well-organized, but luxuriant at the same time. Climbers like clematis, roses, wisteria and ivy will add vertical componants, which give an aristocratic appearance to the garden.
To get this style realized, you  will need a minimum-area of about 300 square-meters. And the house should be stand-alone or semi-stand-alone. Otherwise this style would not show to full advantage and would seem to be misplaced.
Once constructed the maintanance isn't too much work. But of course weeding on a regular basis and some cutting will be necessary every year.