I have grown yellow squash and zucchini into a single stalk 4 ft tall “tree”.. my granny (great grandmother) used to do this and other old Indian tricks in the garden, but this one I remember (I was just a small boy last I’d gardened with her) and have repeated this over the years with great success.. you must support it from early on, and when it flowers (2 at a time) it puts off 2 more stalks/stems/branches (don’t really know the term for squash branches), when you take the fruit (2) you take off bottom 2 stalks/stems/branches, it just continues to stack on top of each other growing up as it goes.. it’s really neat to see and it keeps air circulating and bugs at bay..