Questions on what/how much to fee pet geese? very confused currently

On feeding you need a waterfowl feed. Now because I have Sebastopol's I may feed differently than for Africans. But as a rule of thumb all geese should eat waterfowl feed. At this time of year I cut the feed protein down to 15-16% by adding half waterfowl feed and half whole oats mixed together. Yes, you are feeding too much. You should give what they can eat in 15 minutes. This is how I feed my Sebastopol's once in the morning only enough that they can eat in 15 minutes. Then they for the rest of the day free range. Only as a treat you give goodies. I have never fed a banana to my geese. Cut up tomatoes, cut up grapes red or green, watermelon, cantaloupe, romaine lettuce, kale, apples. NO spinach it is too full of iron!
Then for bedtime to put them in their pens I feed the same way all they can eat in 15 minutes.

There will be others who will chime in on what they feed as well. I do believe that they can eat celery, carrots and other things too. But not all the time because too much of a good thing can make them sick or not be good for them... We tend to want to treat our geese so well we can over due for them. I know I can.

 

I'm following the same basic feed routine as Ruru. My geese also love dandelion greens, kale, collard greens, cabbage, apples and pears. The majority of the goose diet should be greens. I don't allow my geese to have full access to every area in my garden. If the area where they are free ranging gets overworked, I will cut grass and harvest dandelion greens in other areas of my yard and bring it to them. I have apple and pear trees in my garden and grew kale for them this year. The grass gets a little sparse toward the end of summer, so I supplement their greens accordingly.

You might want to check with your local grocery store's produce department to see if they would be willing to give you their vegetable discards for your goose.