Set vertical dock priority over horizontal with DockPanel Suite

I'm using DockPanel Suite but I've run into an issue due to the relatively sparse documentation.

I have two docked panels: one which docks left and right, called "Side", and one which docks on the bottom, called "Bottom". I would like Side to fill the height of the form, with Bottom filling up the rest.

So what I'm aiming for is this:

But what I have instead is this:

When I run the program, I get the second variant, and if I drag Bottom out to float it, then drag it back, it will dock the way I want it to, but I can't achieve this programmatically.

Here's my code:

public Form1()
{
    InitializeComponent();

    SideForm side = new SideForm();
    side.Show(dockPanel, DockState.DockRight);

    BottomForm bottom = new BottomForm();
    bottom.Show(dockPanel, DockState.DockBottom);
}

I've tried changing the order, but that has no effect. I've tried poking around the various properties and methods, but there's not much documentation, so IntelliSense is not much help here.

Does anyone know of any tricks to get this working programmatically?