Marigold - Seed Saving
Marigolds are easy to grow from seeds and just as easy to save for next year. They supposedly help discourage insect pests in the vegetable garden but I plant them because they are carefree and colorful. I even like the smell.
I collect marigold seeds in the fall when I start cleaning up the garden. The dried out brown seed heads are best, but you may be able to germinate seeds from the almost-dry ones if thats all you've got.
Mature seeds will be dry and stiff and can be easily pulled from the seed head. Each seed head will give you tons of seeds, so collect a few handfuls and share with friends.
below: compare mature, dry seeds on the left to green seeds on the right
Marigolds will cross pollinate with your neighbor's plants, so the next generation of plants may look a little different. My plants from saved seed tend to be taller, with mostly orange flowers. If you really want dwarf plants or fancy flowers, you may want to isolate some blooms with a net bag or purchase seed each year.