|Two questions actually
1. What does it mean to
|Pinching is a form of very light pruning. Usually it means to remove the soft growing tip of a new shoot, nipping it off just above a leaf or pair of leaves or branching point. This is done when plants are young, often at the seedling stage, to encourage them to branch and grow denser. The word pinch comes from the way many gardeners perform this task -- by literally pinching off the tip with their thumb and first fingernail.
You can broadcast a granular fertilizer on top of the mulch, but it is better to pull the mulch aside and sprinkle the fertilizer over the root area, then replace the mulch. This helps the fertilizer dissolve better because it is in contact with the soil. It also will act somewhat faster because it does not have to leach down through the mulch and then through the soil, it is at soil level from the start. Another consideration is what kind of plant you are trying to fertilize. Often, mature shrubs do not really need extra fertilizer. An organic mulch and an occasional topdressing of compost should be sufficient.
I hope this answers your questions!