No amendments, only water (my well is 8.1 pH). Worm castings, about 30 pounds per plant with the straw top dressed with broadcasted castings prior to a replanting anf just prior to a spring rain. These castings where delivered by home depot by the ton. They have been outside in the soil for almost a month. The largest are almost 6 feet. The growth has been almost a foot a week. I have not watered in 2 weeks though the ground is moist and cool under the straw. The metal posts warm the soil a bit too. Left out of the ground, in the sun, they would burn you to touch. In the ground the heat transfers into the soil keeping the cool to them touch. I'm hoping this may deter PM not only with the temps but from the added iron, via rust. Rust away. They will still last 50 years. The plants are connected with carabiners and thin bicycle tubes, crossed to form a barrier between the metal and stem