Posted: 02/11/2012 at 12:20
Snapdragons are perennials usually treated as annuals. You can get two years out of good plants by leaving them over winter (or cutting down by 1/3 if very tall) and cutting back to green growth in spring. The second year's plants can be as good as the first.
Osteospermums may survive in warm areas - trim lightly to tidy up and wait and see what happens in spring.
Gerberas - unless they are the new "hardy" variety will die over winter. Hardy ones may survive in a warm area.