With the seasons changing, so shall Strudels! You'll find new crops are available and the old ones retired until next summer! Don't fret: If you had any seeds or current crops growing they won't disappear! You just can't get new seeds until they come back around.
You will also find some new items while fishing! Of course certain items like garbage and twigs can always be fished up, but might there be some more Autumn-appropriate pets? Why don't you give it a try and see!