When you have a plant that is not a true annual, saving is possible. Impatiens hawkeri (the New Guinea kind) & Pelargoniums (your citronella "Geranium") are perennials, and some Petunias. Sounds like you're on a track with potential for great & fun success!
Some of my fav houseplants found in the annuals section, so many Coleus, so many Begonias, calico plants / parrot leaf (Alternantheras), Persian shield (Strobilanthes dyerianus,) "spikes" (Cordyline indivisa, C. australis, and sometimes Dracaena marginata,) ornamental purslane (Portulaca umbraticola,) polka dot plant (Hypoestes,) various Plectranthus (Cuban oregano, 'Mona Lavender',) Tahitian bridal veil (Gibasis geniculata,) Perilla 'Vanilla' & 'Magilla',,,
