Select amaranthus flowers that are at full bloom from your garden or a local nursery.
Cut the flowers from the plant leaving a long stem.
Trim the leaves from the stems to prepare the flowers for drying.
Group the flowers into small bunches and tie them together with a long string. You can also dry each stem individually if the bunches will crush or distort the natural shape of the blossoms.
Hang the flowers upside down in a warm, dark, well-ventilated location such as an attic or closet. Leave the flowers undisturbed for two to three weeks.
Feel the flowers and check for moisture. If the base of the flowers is still moist, allow the flowers to hang for another week and check them again. Once fully dry, the flowers are ready for use in a floral arrangement.