definitely u can shoot well w/o tripod
half of the "typical landscape" type of shots can be done w/o tripod, that is where handholding skill is required(it is attainable: eg aim for 1"s @50mm, f2, ISO400 minus 1stop at 9+pm...thats what i did when i sneaked a shot of some outdoor function at chijmes)
the other half of the 'nice nice landscape shots" are done with a tripod. for landscapes, as long as the wind sdoesnt blow down the tripod, then it is a good tripod. tripods range from cheap deals (<$50) to those meant for telephoto lenses (>$5000+)
the criteria is that as long as it works 4 u then its ok.
alternatives to tripod also are ok--that is , as logn as they work