The [[maximum slope]] on which you can sow seeds is 8; attempting to sow seeds on a greater slope results in a message "The ground is not flat enough for crops to grow. You need to flatten it first". The slope does not appear to effect growth speed or crop quality.
Sowing on a sloped tile takes into account it's compound slope, however. That is, it's slope both North-South (NS) and East-West (EW). For example, the slope can be level EW and 8-steep NS. Or 4-steep EW, 4-steep NS etc.
== Examine details ==