Moss rose flowers prolifically with little care. If you enjoy having reseeding annuals in your garden, these will often return year after year, even in poor soils and hot, dry locations, according to Clemson Cooperative Extension.
Although moss rose will likely reseed, the seedlings will not necessarily replicate the parent plants, states the Aggie Horticulture website. In addition, the Westmoreland County, Penn., Extension's evaluation of several moss rose cultivars noted that at least some are difficult to deadhead. Thus, you may find it difficult to prevent unwanted seedlings.
If you want moss rose to reseed, be sure to set out your plants early enough so that they have time to flower and set seed. Avoid deadheading the spent flowers or cutting the plants back. If you prefer to grow particular cultivars, purchase new plants each year, rather than relying on reseeding.