I've got some cells where the content is to big for the cell.
How can I adjust the height of the rows when the content doesnt fit in width?
I would recommend you to use text wrapping which described in the answer (word wrapping) and in this one (char wrapping). I would recommend you additionally read the answer which described advantages and disadvantages the usage of the two ways of wrapping. In both approaches will be used
.ui-jqgrid tr.jqgrow td {
height: auto;
}
which can be helpful not only in case of text wrapping.