Some bedding plants are easier to maintain and keep looking good all summer than others.
In summary: Petunia, surfinia, verbena, pansies, Ice plants all hard work as they need lots of dead heading, plus French marigolds slug magnets, and sweet peas attention seekers. Geranium, Begonia, Calendula and Nasturtiums, easy and undemanding.
Petunia, surfinia, verbena, pansies, Ice plants ( Mesembryanthemum) all need a lot of dead heading, but some more than others. If you want an easy gardening life, Mesembryanthemum is not the bedding for you. This is because Mesembryanthemum, when in full bloom, produces dozens and dozens of spent flowers to be removed. As a bedding plant, it looks fab, but very labour intensive. See below the lovely bright blooms left, and the heap of spent flowers, all of which were removed in just one dead heading session, center image.
If bedding plants are not dead headed, they will stop flowering earlier in the season. A plant flowers and sets seed, that it's aim, and having achieved this, it will not keep on flowering. By removing the spent flowers, it forces the plant to flower again in order to set seed and keep on flowering.
Sweet peas are another labour intensive bedding plant. Obviously beautiful scent and colours, but hard work. I grow them every year and I love them, but they take a lot of effort to keep them blooming and looking good. It is essential to keep removing the spent flowers and seed heads all summer long, and there will be plenty. Also, to stop the plant becoming a tangled knot by halfway through the summer, you need to remove the tendrils as well, see the image below right and tips on growing sweet peas.
Video about removing sweet pea tendrils.
Easier to grow and maintain are Pelargoniums, commonly also known as Geraniums, which are not troubled by slugs and need only a modest amount of dead-heading, and are drought resistant. Geraniums will benefit from a feed but will still put on a good show without being fed. Geraniums can also be overwintered in a frost free environment to have free plants for next year.