Although the tiny envelopes of seeds from the garden center are convenient, they're also expensive. If you want to save a few dollars, consider saving seeds from existing plants. It's an interesting hobby, and once you successfully grow plants from seeds that you gathered the previous year, you'll be hooked. Although all plants develop seeds that can be saved, annual flower seeds from plants that grow for only one year are the easiest.
Select a few healthy blooms and tie a colorful piece of string or yarn around the stem to remind you so the bloom won't accidentally end up in a flower arrangement .
Keep a close eye on the selected blooms. When the blooms begin to fade and turn brown, you'll know that flower seeds are beginning to form. When the blooms are completely dead, it's probably time to harvest the seeds. Shake the bloom; if it rattles the seeds are ready.
Hold the bloom over a paper bag and shake the seeds into the bag. If the seeds aren't quite ready to come out, put the entire bloom in the bag.
Put the paper bag in a dark, cool place and leave them for about a week, shaking the bag gently every day. If the seeds are hard and you can't smash them with your finger, they are ready to store. If they aren't completely dry, leave them for a few more days.
Spread the seeds out on a cookie sheet and pick out any large bits of stems, seed pods or petals, but don't worry about any small bits. Pour the seeds into a white envelope and put the envelope in a cool, dry place until spring. Label the envelope so you'll know the type and color of the plant.