There used to be a Start new season button. But it was easy to forget and hard to find. We've completely changed how seasons work, so you don't need to remember to start them any more.
A season is now a view, not a thing
A season is worked out from two facts you already have: the date on a record, and the month that crop's season starts. Together those name a window of twelve months, and everything dated inside it belongs to that season.
Nothing is filed into a season, so nothing can be filed into the wrong one. Correct a date and the record moves to where it belongs, on every page and in every report, without anything else being touched.
A season selector in the sidebar changes which season you are looking at. It only changes what you see — it writes nothing.
You can move a crop's starting month yourself
This used to need us. It is now on the crop, under Crops.
Take it seriously, though. The starting month decides where every season begins and ends for that crop, as far back as your records go — not just from now on. Move it and history is regrouped with it, so a report you ran last week may not come out the same way again.
That is the trade for never having to file anything: the boundary is derived, so moving the boundary moves everything derived from it. Move it only if you made a mistake initially, or if you are changing the way you work and want to see the effect on your history.
The full picture
Seasons are per crop, not per farm — so on one day in May a farm can be ten months into its grape season and two months into its citrus one. Why that is deliberate, where exactly a boundary falls, and what "this season" means when you have not chosen one: How seasons work.