public class FertilizerGraph extends JComponent {
	
	public void paintComponent(Graphics g){
		
		Graphics2D g2 = (Graphics2D)g;
		Rectangle box = new Rectangle(5,10,10,30);
		g2.draw(box);
	}
}

// snippet from another GUI class

	public JPanel createGraphPanel() {
		JPanel panel = new JPanel();
		panel.setSize(300,50);
		panel.setBorder(new TitledBorder(new EtchedBorder(), "Parts graph"));
		FertilizerGraph fertgraph = new FertilizerGraph();
		panel.add(fertgraph);
		
		return panel;
	}