My favorite kind of volunteer however often occurs in my garden. The sweet little violets you see above started showing up five years ago. I never planted a single seed but expect that the birds brought them in. Perhaps the guy up above? In any case they arrive and I let them flourish just where they land.
I hope you are having a lovely spring/summer. By the way another volunteer that has not shown up this year is Cleome. I will leave you to look that one up and if you cannot find one ask and I will post a photo. let me know what you think