The Right Place
Plant them into the ground in a spot with at least four to six hours of direct sun or all day-dappled sunlight. Soil should be well drained and rich in organic matter, so add peat moss, leaf mold or compost to the soil before planting. While improving the soil, also add either super phosphate or bone meal for the important supply of phosphorus for the roots, following label directions.
Planting Nursery Stock
Most miniature roses are shipped in small pots in leaf and sometimes in bud or bloom. Unpack them as soon as they arrive and put them in good light but not full sun right away. Once they become acclimated, they can be set in their final spot. Make sure they are kept well watered during their transition from the dark shipping box to the sun.
Miniature roses should be planted a distance apart equal to two-thirds their ultimate height, unless you are using them as a tight hedge, when they can be planted closer together. Set them far enough from larger plants that could deny them soil nutrients, sunshine and moisture.
If you remove the blooms or buds at planting time, you will force the energy of the plants into growing roots, which will make them stronger.
Miniatures are particularly suited for container gardening and even do very well indoors. Miniatures prefer pots 6 to 10 inches in diameter. When raising roses indoors use a synthetic soil mix to avoid fungal disease and provide cool temperatures (60°F.) and high humidity. Move roses in containers to unheated shelters when the temperature falls below 28°F.
For more information see file on Planting Shrubs.