I have no idea what the rate of growth is in an IE in zone 6. Here in zone 9b its 10-18' per year in all direction until they reach their maximum height. My IE was the last tree to come out of dormancy. I posted a picture of it roughly three weeks ago. Since that picture its grown 2' plus in all directions. It's already grown total of 4-5' in all directions since coming out of dormancy. Does that sound like fun to you?

If you do this please post pictures. Start to finish over the first few years. It will be fun to watch so lots of people will follow the thread.

Actually, that does sound like fun to me.

I have it in a very large pot, and it's not in exactly full sun. I hope those factors help to keep it somewhat dwarfed.

I figure I will need to root prune at least every other year, and eventually put it in the ground because the trunk is going to get too big but I think I am going to experiment with it.

I think it will work fine, but the birds will have such easy access I doubt you will get much fruit.

Mulberry bears on spring wood and can take a lot of cutting back without problems so it should fruit for you. You probably need to remove the most vigorous shoots and leave the thinner ones to bear your crop and you will probably have to do an awful lot of pruning all summer long.

Good luck with that.
I've seen folks liken pruning/training IE to trying to control a firehose.
Maybe if you ringbark it every so often, you can slow it down.

Great suggestions. Thanks

I read once that if you brush away the soil around the junction where the trunk meet the roots you will see a large root growing out along the surface of the soil. Chop through that root and it will stunt the tree and not make it so tall. You may need to root prune and summer prune and winter prune to keep it in line. Some of the places you see wild mulberries surviving - gravel, boulder filled rocky places with no water and no soil - I imagine you can keep one alive no matter what you do to it.

All my mulberries are small (though fruiting) and all will be pruned heavily to keep them bush sized. Most of the plants in my yard require a lot of pruning so none of this bothers me.