Several years ago, I had a petunia plant purchased from a nursery. The
plant was deadheaded daily by someone who, during that period had
surgery and used the time tending the flowers as their outside time to
heal.

So....I had left a few flowers on and gathered the seed. I stored the
seed in the refrigerator and started the seeds in a few peat pots just
enough to get one hanging basket worth of plants "in remembrance" of
that summer.

I was told correctly that the resulting flowers would probably not be
the color they were but purple. Each year, I leave a few flowers on to
collect the seed, store it, and start a fresh plant in the Spring.

The question: Each successive year it seems the seed is less able to
germinate. This year I tried almost 30 seeds and got 5 plants and 3 died
at the 2-4 true leaf stage. I don't have this problem with other plants
or with other petunia seeds. Is it possible for a plant to basically
become more sterile such that any seeds produced just don't work anymore?

Thanks,

Charles