How do I control the tick label size in flot

I have a basic bar chart I'm presenting in flot (5 bars, displaying the % per status).

$.plot($("#placeholder"), [
    {
        label: 'Failed',
        data: [[0,10]],
        bars: { show: true }
    },
    {
        label: 'Passed',
        data: [[1,15]],
        bars: { show: true }
    },
    {
        label: 'Not Run',
        data: [[2,30]],
        bars: { show: true }
    },
    {
        label: 'Blocked',
        data: [[3,5]],
        bars: { show: true }
    },
    {
        label: 'In Progress',
        data: [[4,40]],
        bars: { show: true }
    }
],
{
    xaxis: {
        ticks: [[0.5, "Failed"], [1.5, "Passed"], [2.5, "Not Run"], [3.5, "Blocked"], [4.5, "In Progress"]]
    },
    legend: {
        show: false
    }
});

I'm finding the font used for the tick values on the x axis are a little too big, especially when the graph is displayed at small dimensions ie. 240x100. I've read the API documentation, but can't find how to control the tick label sizes.

Is this possible OOTB?