Oh boy, Johnny jump-ups definitely have healthy germination and re-seeding rates. I planted some in one of my garden beds last year and they came back in full force this year in the next garden bed over (I'm attributing it to the wind). They are actually the ONLY blooms remaining in my garden. I'd forgotten about them until I was looking at my irises the other day and realized, with amusement, that there were still a bunch of purple and yellow Johnny Jump up blooms in the middle of the garden box. We've had some hard freezes here, too, getting down into the 20's at night, so those are tough little suckers! A welcome, cheery bloom this late in the season, though. They never stop blooming once they start in late spring and apparently they go on well through fall, given the right conditions.
Mary - I didn't collect any seed this year...the blooms are so tiny that I'm not sure how to go about it. I suppose simply cutting the flowers later in the season and putting them upside-down in a paper bag until the seeds fall off would do it, but how do you know when the flowers have been fertilized and started to develop seed pods?...
