We have pine trees here on the slope. We had probably 20 years worth when we moved here. I used a lot of them when I originally made the beds, digging them in well. Everything seems to do fine here, all the bulbs do well in the ground. It takes a couple years for them to break down. I tested the beds a couple years ago and they are just on the acid side of middle, rather than alkaline like most soils are in this part of CA. Cathy Craig San Clemente CA Zone 9b President: Pacific Bulb Society