Sidebar submenus block menu

When using a Custom Menu with submenus, the horizontal menu across the top of the page is excellent. Hover over a menu option and the submenu drops down, showing further options. Great!

But in the sidebar, the menu is displayed vertically and the dropdown menu still drops down, essentially blocking all menu options below it. And it stays dropped down until you move the mouse all the way off the sidebar.

Is there a way to have vertical menus shoot the “dropdown” box out to the right? Maybe it can’t move off the sidebar itself, but it could be right-aligned, maybe? Just so that when you’re reading the menu with your mouse, the rest of the menu isn’t blocked out.

Know what I mean?

Thanks!