for (int i = 0; i < 4; i++) {
  for (int j = 0; j < 4; j++) {
    if (i % 2 == 0) {             // if i is even
      if (j % 2 == 0)             // and j is even
        plantMany(i, j);                 // plant
    } else {                      // otherwise (if i is odd)
      if (j % 2 == 1)             // and j is odd
        plantMany(i, j);                 // plant
    }
  }
}