Sample root pruning protocol for nursery production
Spade root pruning was accomplished by slicing a square tipped balling shovel 36 cm (14 in) long into the soil at an angle similar to that of a mechanical tree spade. North and South one-eigth circumference segments (12.5 percent of circumference each, totaling 25% circumference) were pruned in April 1999 20 cm (8 in) from the trunk and East and West one-eigth segments were root pruned in May. Root pruning was repeated in August (NW and SE segments) and September (NE and SW segments) 27 cm (11 in) from the trunk. The bottom of the hand spade did not reach far enough into the soil to overlap adjacent slices so any roots growing directly down under the trunk were not cut.