Is it necessary or important to remove dead flowers after they bloom?
Deadheading or removing dead flowers after they bloom will often improve the appearance of the landscape, producing a cleaner look. Although deadheading takes time, it will not become burdensome if you remove a few every day, or at least once a week.
Removing dead flower heads also prevents seed production. Since seed production is the main goal of most plants, deadheading sometimes stimulates additional bloom. Roses in particular will bloom better if dead flowers are removed. Plants with woody stems, like roses, need to be deadheaded with pruners. When removing spent flowers from roses, prune just above a five leaflet node. Nodes with only three leaflets will produce thin, weak stems.
Most flowers can be deadheaded by pinching with the thumbnail against the first or second finger. I like to pinch off the entire flower stem so no stubs remain above the leaves. Some flowers, such as geraniums, have a joint at the bottom of the stem and will snap off easily at the joint. Stems that do not break or pinch easily will need to be pruned off. I always carry my pruners with me whenever I walk through the yard so that I can remove dead flowers or prune dead branches. I usually spend about 10 minutes each morning weeding and deadheading.
Most perennial flowers need to be deadheaded. However, many of our most popular annuals need very little, if any, deadheading. They either drop their flowers naturally or produce new growth which covers mature flowers. If you want to minimize deadheading, petunias, pansies, begonias, impatiens, verbena, marigolds, alyssum and lobelia are good choices to plant.