I have two TextField in my model. But i want to change the rows and cols attribute of only of the TextField. I know from this page that the look of TextField can be changed using the following code in the admin.py.
class RulesAdmin(admin.ModelAdmin):
formfield_overrides = {
    models.TextField: {'widget': Textarea(
                       attrs={'rows': 1,
                              'cols': 40})},
}
...
admin.site.register(Rules, RulesAdmin)
As I said, using the above code changed the look of both the TextField, I want only to change one of those here is how my model looks like:
class Post(models.Model):
    title = models.CharField(max_length=200)
    content = models.TextField()
    pub_date = models.DateTimeField(auto_now_add=True)
    update_date = models.DateTimeField(auto_now=True)
    meta = models.TextField(blank=True)
    def __str__(self):
        return self.title
I want only to change the look of meta field. 
How should I go about this ?