BUG: Plotting with PeriodIndex with frequency > 1 leads to wrong x-axis

[gorold]

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

from datetime import datetime, timedelta
import pandas as pd

date_today = datetime(2023, 2, 2, 0, 0)
days = pd.date_range(date_today, date_today + timedelta(minutes=10), freq='5T').to_period()
data = np.random.randint(1, high=100, size=len(days))
df = pd.DataFrame({'index': days, 'data': data}).set_index("index")

display(df)

df.plot()

df.index = df.index.to_timestamp()
df.plot()

Issue Description

Plotting with PeriodIndex with frequencies larger than 1 (e.g. 5T, 60T, ...) plots the x-axis as the end of the period, rather than the start of the period.

The created dataframe:

Plotting directly:

Changing to DatetimeIndex:

ng)

Expected Behavior

The expected behaviour should be that what is shown for DatetimeIndex.

Installed Versions

INSTALLED VERSIONS

commit : 2e218d1
python : 3.9.12.final.0
python-bits : 64
OS : Linux
OS-release : 5.10.133+
Version : #1 SMP Sun Sep 11 08:45:44 UTC 2022
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : C.UTF-8
LOCALE : en_US.UTF-8

pandas : 1.5.3
numpy : 1.22.3
pytz : 2022.1
dateutil : 2.8.2
setuptools : 67.1.0
pip : 23.0
Cython : None
pytest : None
hypothesis : 6.56.4
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : 2.9.5
jinja2 : 3.1.2
IPython : 8.4.0
pandas_datareader: None
bs4 : 4.11.1
bottleneck : None
brotli :
fastparquet : None
fsspec : 2023.1.0
gcsfs : None
matplotlib : 3.6.3
numba : 0.56.4
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : 11.0.0
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : 1.10.0
snappy : None
sqlalchemy : 2.0.2
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
zstandard : None
tzdata : None

[azjps]

Here's the source of the issue if someone wants to follow up:

> pandas/pandas/plotting/_matplotlib/timeseries.py(311)maybe_convert_index()
    309             if isinstance(data.index, ABCDatetimeIndex):
    310                 data = data.tz_localize(None).to_period(freq=freq_str)
--> 311             elif isinstance(data.index, ABCPeriodIndex):
    312                 data.index = data.index.asfreq(freq=freq_str)
    313     return data

ipdb>  p data.index.asfreq(freq=freq_str)
PeriodIndex(['2023-02-02 00:04', '2023-02-02 00:09', '2023-02-02 00:14'], dtype='period[min]', name='index')
ipdb>  p data.index
PeriodIndex(['2023-02-02 00:00', '2023-02-02 00:05', '2023-02-02 00:10'], dtype='period[5min]', name='index')
ipdb>  p freq_str
'min'

Tagging as tangentially related to #52895