Even as per mother nature's intent, the seeds are generally viable for one year atleast.. it can be more depending upon whether its vegetable, flower or herb seed
I think aster season is gone since it should have been sown in Oct. Experts can tell better
Yes, they do get expired... they are living things, if not properly stored.. they quickly loose their life.. if you want to save seeds then you must get them dried in shade for a week then keep them in a dry container (glass or plastic) with cap closed and put it in a cool place, like lower part of fridge. By this method they remain alive for many years.
Sometimes seed sellers keep their seeds open, which are affected by air, temperature and humidity. They loose their vitality and die before their expiry date as mentioned on label. Some seeds are tough like marigold, poppies, beans, sunflowers and some are weak like gerbera hardly survives 2-3 months in proper storage..
Buy seeds from reputable sellers and always store them as per advice above.
Petunia and Pansy seeds are difficult for most home gardeners, you should have tried bigger seeds like marigold, aster, nasturtiums, dahlia, cosmos..
The time for every winter season is from October till November... now you should try summer flower seeds like zinnia, yellow cosmos, gaillardia, balsam, vinca..
