Last year, I planted TWO hollyhocks, both out in the veggie garden. Figured they'd bring in the bees by the boatloads, and I was right. And never gave a thought to the whole 'self-seeding' bit. I went thru that with the bloody cosmos, which are STILL popping up from time to time even tho I ruthlessly tried to eradicate every single one that I saw and cut the flowers off the ones I missed or left for the bees. And before the cosmos was the borage, and yep, still yankin' them outta the garden altho the ones on the perimeter I leave for the Bee Girls. I keep forgetting that unlike SoCal, if a fertile seed so much as gently touches the ground - any ground - around here, within moments it's sprouting and from there on out, it's a race to see what grows the biggest the fastest. If you actually planted something on purpose, you better stand back once the soil is tamped down around the newly planted.
So, the hollyhocks. Dale has ruthlessly sprayed the ones that popped up in the gravel parking area next to the veggie garden and around the old red barn and the dairy barn garage. I kept after the ones that were popping up in inappropriate places around the garden, but they got way ahead of me at the cuke A frame, so I let them have that and planted the cukes on the pea fences this year. But around where the original two were came up glorious colours and colour combos, tall and strong (and yes, pretty rusty as hollyhocks are wont to be) and absolutely traffic stopping.
I suspect that next year will be much worse. Maybe I can charge people to have their pictures taken in the middle of them.