concatenate Null DateTime to String

I am trying to concatenate two dates but when one date is null do not add Default date, leave blank C#. I am trying the code below but is not working
if ((DateTime.TryParse(val, out sDate)) && (DateTime.TryParse(val2, out dDateNew))) pLabel = sDate.ToShortDateString() + Environment.NewLine + dDateNew.ToShortDateString(); else pLabel = string.Empty; if any of the Dates are null just leave it blank.  I am getting default date of 01/01/01 with the code above. Any help will be appreciated.