Spacing
Proper spacing is important for producing garden mums with beautiful round shapes. Pots grown too close together will have an upright, stovepipe appearance even when the right varieties have been selected and proper fertilization has been given. Pots should be spaced to allow the plants to reach the desired head size without touching the adjacent plants.
Small 3" and 4" pots can be grown on spacing ranging from pot-to-pot all the way up to 7" centers. Six-inch pots for spring and summer crops can be spaced on 7"centers up to 12" centers. Wider spacing can be used for 6" fall crops and fast crops as larger head sizes are generally seen. Fall crops in 8" pans or nursery containers are typically spaced on 18" to 24" centers.
Finished plant head size and sales price will be the major determining factors on what spacing should be used.