Somebody Lending Me Land For Free

[landscapetastic]

Hi,

Sometime ago I found a ad on craigs list about land that somebody is letting people use for free. I responded and met with the guy, I told him I wanted to grow trees on it. I asked him what it was in for him , he said nothing and that he wanted to help somebody out. You can use the land for free. What type of legal protection should I have before planting trees on it , since trees are a big commitment before selling them 5- 7 years from now. I live in NY