Bilberry will not survive my hot summers here in zone 7b/8 I have enough trouble just keeping the honeyberries healthy looking in summer. I'm not sure what zone you are in but in my area blueberries are successfully grown with irrigation and mulch along with proper soil preparation. I know being a permie you hate to hear the word irrigation but blueberries are very shallow rooted and naturally live in moist environments with tons of rainfall and decent draining organic rich soil with a low ph. At the same time they don't like to sit in water either. It's easy to keep deeper soil moist using swells but the top 6 inches is a challenge for many who are plagued with drought in summer. I planted over 200 blueberries about 150 were planted without irrigation to test and see if they would survive. Out of those 150 only about 10 are still hanging in. The others were planted in raised beds or in pots and are watered often and doing just fine. My native blueberries do well along the woods edge but they only produce about 1-1.5 lb of fruit per mature plant. Commercial blueberries don't make a good candidate for permaculture design in my area but are well worth growing if you can supply the extra water needed because they average 10-25lbs per mature plant depending on cultivar and growing conditions. There are both high chill and low chill varieties. If in zone 8 or higher you should go with low chill cultivars if in zone 6 or colder I'd go with high chill but those of us in zone 7 can get the best of both worlds. I would imagine Alabama gets a good bit of precipitation off the gulf so they may work in a permaculture design better for you it's really all about trial and error because each place is different even if in the same hardiness zone. I hope this helps.
