In the past I have grown yard-long beans along the back row against my wooden fence and allowed them to run up strings attached to the fence by nails. This next growing season, I plan to use containers attached to the top of the rence to grown them down, instead of up. My current plan is to use gallon milk jugs with the shoulder opposite the handle cut out. I will run a wooden rod through the handles and suspend the jugs on the rod by attaching to ends of the rod to the fence posts. I will drill five 1/2 inch holes in the bottom of the jugs; place rocks in the bottom of the jugs to prevent loss of soil; and fill the jugs with my potting soil mix of 1 part garden soil, 1 part top soil, a cup of worm castings, and 1/2 cup of vermiculate. I will plant 3 seeds per jug and train the plants to trail over the sides. When the plants reach the soil I will prune them to prevent exposure to deseases. When I posted this on the vegetable gardening site, I was advised that 3-4 seeds was excessive; that worm castings were not suited for beans; to use potting soil vice my soil mixture; and that the jugs would probably deteriorate during the season. I chose not to build a potting box due to the cost of durable wood such as cedar or redwood. Any advice on an alternative to the jugs or the expensive wood?