Luke: the only one I've ever seen recommended was squash and that was the under-story of a peach orchard. The text was published in 1899. Most of what I've researched in the last 2 years suggests keeping the area where the tree roots reach to and further remain vegetation-free to avoid competition and sites for the fruit tree's enemy's (insect and microbes) to proliferate and/or overwinter.

Some suggest cover crops like oats in the fall or various clovers. Under a peach, especially growing in very fertile soil, you might want to avoid anything that adds nitrogen back to the soil to avoid excess growth as peaches are prone to that.

Michael

Thanks Michael. I read that chives are a good companion plant for apples but we already have lots of them so don't really want to plant anymore!

Hi, Luke. This winter I'm going to try onions. They're shallow and don't offer cover. I'll use extra care not to disturb the tree roots. Misterbaby.

I think a lot of veggies and flowers can be grown under apple tree. But if the tree is of some value to you, you should not try to damage its surface roots.
So, having said that I will not plant anything under the canapy of an apple tree. If you want to plant anything, you will need to loosen up and cultivate the soil. Doing this will will have to cut some tree roots. Another method wood be to bring soil from somwhere else any plant in it without disturbing the tree roots.

thanks for the advise guys!