private void start() {
        new BukkitRunnable() {
            @Override
            public void run() {
                if (!getZombies().isEmpty()) {
                    for (LawnTile tile : tiles) {
                        if (tile.isPlantHere()) {
                            Plant plant = tile.getPlant();
                            if (plant.getType().getDelay() != 0) {
                                if(plant.canShoot()) {
                                    new BukkitRunnable() {
                                        @Override
                                        public void run() {
                                            plant.shoot();
                                            plant.resetDelay();
                                        }
                                    }.runTaskLater(PlantsVsZombies.getInstance(), 1);
                                } else {
                                    plant.addDelay(20);
                                }
                            }
                        }
                    }
                }
                if(lawn == null) this.cancel();
            }
        }.runTaskTimerAsynchronously(PlantsVsZombies.getInstance(), 0, 20);
    }