[DefaultValue(0)]
public double AlternateNodeIndent {get; set;}

Property Value

This property is only sensible when the Alignment is TreeAlignment.Start or TreeAlignment.End. Having a positive value is useful if you want to reserve space at the start of the row of children for some reason. For example, if you want to pretend the parent node is infinitely deep, you can set this to be the breadth of the parent node.

This sets the AlternateDefaults's property of the same name.

Reference

TreeLayout Class
TreeLayout Members
AlternateNodeIndentPastParent Property
AlternateRowIndent Property