Both deciduous shrubs which drop their leaves in the autumn or evergreen shrubs having either broad leaves or needles are sold three ways.
Balled and Burlapped (B&B)
Many shrubs, often larger ones, are sold with their roots in a ball of soil wrapped in burlap fastened with twine and/or a wire basket. They have been grown in a field and then dug up for sale.
Many shrubs are now raised in large containers and sold this way. They are easy to transport and hold until planting time. Containerized shrubs transplant very well because their roots are hardly disturbed.
Mail order nurseries usually send shrubs with their roots without any soil on them, protected from drying out by moist sawdust or other similar absorbent material and sealed in plastic. They are typically very young, plants, usually dormant so there are no leaves. Roses are often sold this way.