ChildSpacing property allows you to control the separation between items, in pixels. The default value is (20, 20), which spaces items by 20 pixels in the horizontal and vertical directions. For example, setting the ChildSpacing property to (20, 60) would have the following effect:

<c1:C1OrgChart
   x:Name="_orgChart"
   ChildSpacing="20 60"
   ItemTemplate="{StaticResource EmployeeTemplate }" >
 </c1:C1OrgChart>

Notice how the vertical spacing between items increased compared to the default setting.

You can also control the spacing between items by specifying a Margin value in your ItemTemplate. This approach is slightly more flexible because it allows you to specify the amount of space to be left on each side of the node elements.