One end of a 'lasagna' flower bed I have is between the house and the vegetable garden, and I often dump vegetable scraps into one partially-filled end of it rather than trudge all the way to the compost pile (which is a cold compost pile). This year I have several volunteer plants of some kind of winter squash, and a few tomato plants growing in there among the squash runners. Now buried under the squash leaves are about 30-40 leeks and some Russian kale, too... all planted earlier before the squash and tomatoes erupted.
I decided to leave them all just to see how Nature plays without my intervention... and over time as the squash has crept over the grass outside the bed's timber borders, it means I cannot mow that area. The photo above was taken about 2-3 weeks ago, but since that time the tomatoes are blooming up above the squash runners despite the lack of any decent air circulation... and the squash has budding fruit. Too soon to tell which winter squash it might be, but so far they look like they may be acorn squash. Unfortunately I grew 2 varieties of acorn squash last year, so it will be a while before I know which one it might be, or even if it is a cross.
The winter squash appear to be Thelma Sander's Sweet Potato Squash, shaped like an acorn, and there are LOTS of them budding from this one plant. (I counted at least a dozen on Friday afternoon.) Last year I had only 3 squash from the seeds I planted, and none actually matured large enough to eat... so the squash went in the compost!