Pinching
While a single pinch is still recommended for spring and summer shaded crops, no pinching
is required for fall crops. Cuttings rooted in large plugs and cuttings held in small plugs too long before planting may require a pinch because the cuttings have stretched. On crops that require a pinch, pinching should be done when the plants are ready, not based on a calendar date. An exact number of days from plant to pinch cannot be given. Plants are ready to pinch when they have achieved 1" to 1½" of new growth. This generally takes 10 to 14 days from planting, but can vary with soil types, moisture levels, temperatures, etc. The top half inch of growth should be pinched out. With the use of today’s improved garden mum varieties and proper fertilization programs, there is no longer a need for more than one pinch, or any pinching at all for fall crops. If pinching is done, the last pinch should be given between July 5 and 20 in northern latitudes. In the Northwest and coastal California where nights are cool, pinch no later than July 4 for mid-August flowering. In southern areas, the last pinch should be no later than August 1. Later pinches will produce quality plants, but may delay flowering.
Remember, with today’s improved varieties there is no reason to plant a garden mum cutting in May or early June and pinch it multiple times. Excellent crops can be grown by planting in early to mid-June and not pinching, or pinching only once. Today’s varieties can perform exceptionally well on this schedule. Some growers may find it more economical to plant 2 or 3 weeks later than this, and use 2 cuttings per pot and, again, give zero or one pinch.