Hi Colorado,

Try using hold downs(stakes with a hook part the size of the hose) along the hoses length. The weight of water and heat from the sun will eventually straighten it out. Aloha

Make giant staples out of coat hanger wire.

You have to fasten it down anyway. It changes length by about 4% over a year's temperature variation. Snake it a bit, and fasten down every 6-8 feet leaving the bends free to move a bit.