It is usually better, however, to place them for several weeks in a callusing bed before planting.
"Manual of American Grape-Growing"
U. P. Hedrick
The bottom of the callusing bed is first covered with 2 or 3 inches of sand.
"Manual of American Grape-Growing"
U. P. Hedrick
If left as long as this in the callusing bed most of the scion buds will have started and formed white shoots.
"Manual of American Grape-Growing"
U. P. Hedrick