title: Matplotlib text not showing up in pandas plot
body: <p>I'm trying to add a text annotation to a pandas plot by giving coordinates in a relative range of 0-1 for the axes, but currently the text is not showing up.  Here is some sample code and the resulting plot:</p>
  
  <pre><code>import seaborn as sns
  import pandas as pd
  import matplotlib.pyplot as plt
  
  
  df = sns.load_dataset('iris')
  df['sepal_length'].plot()
  plt.text(0.7, 0.7, 'test')
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/voYBM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/voYBM.png" alt="pandas plot"></a></p>
  
  <p>I'm using versions:
  pandas: 0.24.2
  matplotlib: 3.0.3</p>
  
  <p>on Ubuntu 18.</p>
  
  <p>The annotate() function also doesn't seem to work.</p>
  
  <p>Any clues as to why the text doesn't show up?</p>