Just quit all the running widgets you don't use. Press the OPTION key while hovering the cursor over a widget. An "X" in a circle will appear in the widget's upper left corner. Click on it to close the widget.
Activate the Dashboard, click on the Plus button in the screen's lower left. When the widget strip appears you should also see a new button labeled "Manage Widgets." Click on it to open the management list. Locate the widgets you don't want and delete them.