The following sample has x category axis where all the labels won't fit, but it doesn't rotate the labels accordingly. It has to be resized to ~300 for that to happen.


    @Override
    public void start(Stage stage) {
        stage.setTitle("Scatter Chart Sample");
        final CategoryAxis xAxis = new CategoryAxis();
        final NumberAxis yAxis = new NumberAxis();
        final ScatterChart<String, Number> sc
                = new ScatterChart<String, Number>(xAxis, yAxis);
        xAxis.setLabel("Age (years)");
        yAxis.setLabel("Returns to date");

        sc.setTitle("Investment Overview");

        XYChart.Series series1 = new XYChart.Series();

        series1.setName("Option 1");
        series1.getData().add(new XYChart.Data("four", 193.2));
        series1.getData().add(new XYChart.Data("two", 33.6));
        series1.getData().add(new XYChart.Data("six", 24.8));
        series1.getData().add(new XYChart.Data("one", 14));
        series1.getData().add(new XYChart.Data("one", 26.4));
        series1.getData().add(new XYChart.Data("four", 114.4));
        series1.getData().add(new XYChart.Data("eight", 323));
        series1.getData().add(new XYChart.Data("three", 193.2));
        series1.getData().add(new XYChart.Data("ten", 33.6));
        series1.getData().add(new XYChart.Data("five", 24.8));
        series1.getData().add(new XYChart.Data("seven", 14));
        series1.getData().add(new XYChart.Data("twelve", 26.4));
        series1.getData().add(new XYChart.Data("eighteen", 114.4));
        series1.getData().add(new XYChart.Data("zero", 323));
        sc.setPrefSize(330, 400);
        sc.getData().addAll(series1);
        Scene scene = new Scene(new VBox());
        final VBox vbox = new VBox();
        final HBox hbox = new HBox();

        vbox.getChildren().addAll(sc, hbox);
        hbox.setPadding(new Insets(10, 10, 10, 50));

        sc.getXAxis().setTickLabelRotation(180);

        ((VBox) scene.getRoot()).getChildren().add(vbox);
        stage.setScene(scene);
        stage.show();
    }