1. Not suitable to your tastes or needs
   "the task was uncongenial to one sensitive to rebuffs"; "the uncongenial roommates were always fighting";
   - incompatible
    
2. Very unfavourable to life or growth
   "an uncongenial atmosphere";
   - hostile, unfriendly
    
3. Used of plant stock or scions; incapable of being grafted
   "The uncongenial rootstock rejected the new scion"

See also: disagreeable, incompatible, inhospitable, unfriendly, unsympathetic