Chrysanthemums are beautiful and hardy flowers that bloom from late summer all the way into the early winter months in mild climates. Their "fluffy" blooms are admired for their volume and wide variety of vibrant hues. Many people prefer chrysanthemums with smaller flowers because this makes the plants appear to be a dense explosion of colour, but others prefer to raise "show blooms" that are immense, mammoth blossoms that nearly dwarf the plants beneath them. In order to raise these types of flowers, a gardener must prune or "pinch" a chrysanthemum plant so that all of the plant's resources are concentrated on just one or two blossoms.
Snip or pinch light green growing tips to encourage branching. Once chrysanthemums reach a height of about eight inches, they need to be induced to branch out rather than continue to grow upward. Locate the light green tip at the top of the plant and pinch or clip it off. This will prevent the plant from getting any taller and force it to start growing outward.
Clip dead, dying or diseased flowers and shoots. At least once a week, check your chrysanthemums for abnormal growth, flowers and leaves. If your plants have areas with brown or spotted leaves or flowers that appear to be discoloured or stunted, remove these shoots and problem areas so that the issue does not spread to the rest of the plant.
Snip off dead flowers to keep your plant blooming longer. If you cut off a dying flower, the plant will likely have the renewed resources available to create several more blossoms by the end of the season.
Cut the plants off at ground level once they are done blooming for the season. The tops of the plants will literally die, but you can preserve the root systems so that the mums will return next season. Remove the parts of the plants exposed to the elements and cover them with a thick layer of mulch for insulation during winter months.
Generally, chrysanthemums do not need to have exposed areas covered with pruning paste, but if your plants are not responding well to pruning, you may want to treat the cuts with a thin wound sealer. Also, you can cut at more of an angle to prevent water from sitting on the exposed area.