title: Matplotlib show x-ticks on all subplots and unique y label
body: <p>I am plotting two subplots that share the same x-axis but when I plot I only see the x-axis ticks on the second subplot. How can I make the x-ticks visible on both subplots?</p>
  
  <p>Also I would like to set y-labels for both subplots but only the second is visible. Can you please help in displaying the y-label on both subplots?</p>
  
  <p>Below is my reproducible code.</p>
  
  <pre><code>#!/usr/bin/python3
  import pandas as pd
  desired_width = 1500
  pd.set_option('display.width', desired_width)
  import matplotlib.pyplot as plt
  import numpy as np
  
  
  df = pd.DataFrame([{'DATETIME': '2017-09-29 01:00,', 'Population': 1000, 'Temp': 90, 'State': 'California'},
                     {'DATETIME': '2017-09-29 01:00,', 'Population': 2000, 'Temp': 70, 'State': 'Illinois'},
                     {'DATETIME': '2017-09-29 01:00,', 'Population': 3000, 'Temp': 50, 'State': 'Georgia'},
                     {'DATETIME': '2017-09-29 02:00,', 'Population': 2000, 'Temp': 40, 'State': 'California'},
                     {'DATETIME': '2017-09-29 02:00,', 'Population': 6000, 'Temp': 20, 'State': 'Illinois'},
                     {'DATETIME': '2017-09-29 02:00,', 'Population': 4000, 'Temp': 30, 'State': 'Georgia'},
                     {'DATETIME': '2017-09-29 03:00,', 'Population': 3000, 'Temp': 40, 'State': 'California'},
                     {'DATETIME': '2017-09-29 03:00,', 'Population': 4000, 'Temp': 60, 'State': 'Illinois'},
                     {'DATETIME': '2017-09-29 03:00,', 'Population': 2000, 'Temp': 80, 'State': 'Georgia'}])
  
  df.index = df['DATETIME']
  df.index = (pd.to_datetime(df.index)).strftime("%m/%d %H:00")
  
  fig, axes = plt.subplots(nrows=2, ncols=1, sharex=True)
  
  df.groupby('State')['Population'].plot(kind='line', linestyle='--', alpha=0.5, marker='o', legend=True, ax=axes[0])
  plt.ylabel('Pop')
  df.groupby('State')['Temp'].plot(kind='line', linestyle='--', alpha=0.5, marker='o', legend=True, ax=axes[1])
  plt.ylabel('Temp')
  plt.tick_params(axis='both', which='both', labelsize=7)
  plt.tight_layout()
  plt.show()
  </code></pre>
  
  <p>Current Chart Output:</p>
  
  <p><a href="https://i.stack.imgur.com/GclZF.png" rel="noreferrer"><img src="https://i.stack.imgur.com/GclZF.png" alt="enter image description here"></a></p>