How do i delete the 0 (zero) without crashing the allignment of the field?

For the Defense of Consolas (players guide / java) i'm trying to create a grid/field where the tower must be defended.

The allignment of the code is working so far but i'm trying to delete the zero in the top left where the columns and rows start. Any of you got a trick to delete and also that the field stays the same ? Gr. Stefan

code : 

package PlayersGuide.Opdracht11;

public class TowerDefenseField {
    public static void main(String[] args) {
        int size = 21;
        String[][] field = new String[21][21];

    /*
    make the grid :
    make a for loop that uses a dot "." as placeholder
    This for-loop makes the blueprint for the grid :
    for : int variable for 20 rows, condition : if number of rows is smaller then 20, 
    row increment/+ 1
    inner for loop : int var for columns, condition : if num of col is smaller then 20, 
    col increment/+ 1.
     */
    for(int row = 0; row < 21; row++) { // print 20 rows
        for (int col = 0; col < 21; col++) { // print 20 columns
            field[row][col] = "."; // this prints the dot on every column / row
        }
    }
        System.out.println("   "); // ruimte voor rijnummers! deze worden geprint, 
        //zowel als de nummer die "eroverheen"worden geprint.
        for (int col = 0; col < 21; col++){
            System.out.printf("%4s", col);
        }
        System.out.println("   ");
        for(int row = 1; row < 21; row++){
            System.out.printf("%4d | ", row);
            for (int col = 0; col < 20; col++){
             System.out.printf("%3s",field[row][col] + "   ");
            }
            System.out.println();
        }
    }
}

for (int col = 0; col < 21; col++) {
    if (col == 0) {
        System.out.printf("%4s", "");
    } else {
        System.out.printf("%4s", col);
    }
}

Replace the second for-loop with the above code, and it will work.