uncongenial, incompatible -- (not suitable to your tastes or needs; "the uncongenial roommates were always fighting"; "the task was uncongenial to one sensitive to rebuffs")
hostile, uncongenial, unfriendly -- (very unfavorable to life or growth; "a hostile climate"; "an uncongenial atmosphere"; "an uncongenial soil"; "the unfriendly environment at high altitudes")
uncongenial -- (used of plant stock or scions; incapable of being grafted)