I have some brassica cages made from plastic water pipe and fine netting, built by putting a short section of bamboo canes along the bed both sides at regular intervals then sliding the pipe onto the canes. The problem is that the pipes quickly flop over because they are flexible, and I have nothing to put through the whole pipe to make it stiff. What methods to people use to build a cage from one inch water pipe and make sure the whole structure stays in shape? This is for a bed at ground level (i.e. not a raised bed).