var z1 = new RectangleZone(new List<ZonePoint>() { new ZonePoint(x1,y1), new new ZonePoint(x2,y2), new new ZonePoint(x3,y3), new new ZonePoint(x4,y4)}) // its 1\4 of your thatched zone where you want to plant, in right corner for example
PlantItemsInZone(.....,z1);
var z2 = new RectangleZone(new List<ZonePoint>() { new ZonePoint(x1,y1), new new ZonePoint(x2,y2), new new ZonePoint(x3,y3), new new ZonePoint(x4,y4)}) // its 1\4 of your thatched zone where you want to plant, in left corner for example
PlantItemsInZone(.....,z2);
var z3 = new RectangleZone(new List<ZonePoint>() { new ZonePoint(x1,y1), new new ZonePoint(x2,y2), new new ZonePoint(x3,y3), new new ZonePoint(x4,y4)}) // its 1\4 of your thatched zone where you want to plant, in top corner for example
PlantItemsInZone(.....,z3);
var z4 = new RectangleZone(new List<ZonePoint>() { new ZonePoint(x1,y1), new new ZonePoint(x2,y2), new new ZonePoint(x3,y3), new new ZonePoint(x4,y4)}) // its 1\4 of your thatched zone where you want to plant, in botton corner for example
PlantItemsInZone(.....,z4);