>>2445413>>2445800Do This. Pumpkin vines often root down at the nodes where the a leaf/branch is connected to a stem.
If you have the pumpkin plant sitting on bare soil or light mulch and don't move it at all you'll see it start rooting at those points. Looking online apparently people do bury the nodes on purpose to speed this up, particularly when growing giant pumpkins to get as many roots on a plant as possible and maximize size.