OrgPlus automatically resizes created charts based on the number of boxes included, and the format (or styles), of the branches
One way to resize a chart is to change the style of the branches. This can be done by selecting all the boxes in one branch (either highlight them by dragging a box around the boxes, holding the ‘ctrl’ key and left-clicking on each box, or double-clicking one box in the branch), then going to Home | Chart Styles.
Another method is to use Sub-Charting. Please see the FAQ section on Sub-Charting