squash and marrows

I spent a happy afternoon visiting a garden today in the lee of the South Downs in Sussex under the National Gardens Scheme. It was a beautiful setting in lovely autumnal sunshine. But what really caught my attention were the marrow and squash plants!
I have never ever before seen any squash, marrow or any other cucurbit plants for that matter grow to the size of these, photographed below. These are trailing out of a huge compost bin, and the distance from the nearest point to the furthest in this photo I measured as 15 of my strides, pretty much 15 yards!! And the crop was abundant.
I have tried myself to grow these plants on my own compost heaps but without such success. Perhaps the abundant supply of horse manure from the neighbouring stables was giving a helping hand to those in the photo!
Anyway if mine grew to that size they'd take over my allotment!!