Spring is getting ready in autumn, and a little before!
The first summer flowers have given way for the most part to more or less pretty fruits. On the other hand, inside these fruits there are seeds, which it is often welcome to harvest for autumn sowing (case of perennials and certain biennials - which remain perennials in disguise -) or spring sowing (case of annuals).
Before cutting everything, faded flowers or aging flower stalks, leave enough to have a few seeds in place to dry and then store in dry jars, with a label. Name of the plant, date of harvest are imperative to remember which flowers gave this precious treasure of sexual multiplication.
It is not uncommon to see the following year grow here and there, plants that disappeared last year. Perennials emerging from the ground? Make no mistake about it, the perennial resources of annuals are such that, even with a cleaning of the soil, or even a partial reversal, the new generation of flowers takes place following the parents.
And if you want to have a large number of plants next year, harvest the seeds now. But be careful when sowing to come, the gardener is in principle a champion out of category, overproduction...
