Growers should plant several crab cultivars and have a high percentage of crab trees to assure annual bloom in sufficient quantity to do the pollination job each year. Crabapple cultivars vary tremendously in vigour, just as do regular apples. Variability of tree size is seen even when crabs are on dwarfing rootstocks. This fact makes it more difficult to manage crabs interplanted between regular trees in the orchard. In separate hedgerows or rows, the variability in vigour is not as much a problem, and can be dealt with by means of mechanical pruning.
Crabapples vary enormously in growth habit, just as do regular cultivars.
The preferred growth habit is upright, in which the crab tree naturally assumes a columnar canopy shape. This canopy shape requires less space and is easier to manage. To select crabs with potential for any given cultivar, pay careful attention to bloom dates and use a series of crabs that bloom over the period the main cultivar is in flower. Peak pollination should be aimed at the king-bloom stage. Crabapple tree planted in the row between apple trees with no additional space alotted for the crabapple.