hardy annuals and half hardy annuals.
Hardy annuals can tolerate the cold which makes them suitable for outdoor seed sowing, uasually in early spring around March or April.
Examples of Hardy Annuals are: Chrysanthemum carinatum, Calendula officinalis and Crepis rubra.
Half-hardy annuals won’t survive cold temperatures, so they can’t go outdoors until after the last frost. They will survive until the first autumn frosts. These daisies are only suitable for indoor seed sowing in spring.
Examples of Half Hardy Annuals are: Cosmos bipinnatus, Rudbeckia hirta and the famous Marigolds.
Interestingly some perennials and biennials are grown in gardens as annuals and some growers sell them as such. This means that even when they are labeled as being an annual, in reality they are tender perennials. This usually happens when they are not considered frost hardy in the area where they are sold.
Argyranthemum, Osteospermum and Arctotis are some examples of tender perennial daisies that are usually grown as annuals.
Examples of true annuals include Ageratum, Zinnia and Marigold.