It is all going to depend on the variety. There used to be quite a few apple orchards in Blount county, especially around the town of Hayden. These were Fall apples. You could call the Blount county Cooperative Ext. Services agent to find out what type apple are grown. When I was a kid in the mid-20th century, about the only apples you saw grown around Alabama was the yellow-green "June" apples. No one seemed to know the variety name but the apples ripened in late June and July. We picked them, made pies, jelly, canned, sliced and dried them, They sure made good pan pies and fried pies in the winter

Here is a link that might be useful: Blount Co. ACES office

Like tsmith, as a child in the mid 20th century....
My grandmother had an orchard of Granny Smith trees up in Winston County. I don't recall when they got ripe, because we ate them regardless. She did a lot of canning, and I think that is where her pies came from.

Alan, the following link is a MS state publication and might be helpful. They even list varieties suitable for the coastal region.

Here is a link that might be useful: MSU Apples and Pears

I meant to add that it may be you need a particular pollinator variety for your apples. Call the Auburn Cooperative Extension Agency in your county (probably in Blue Pages under County Gov.) to ask is there is a universal pollinator.

Alan it sounds like your tree is not being pollinated properly. I assume 5in1 means a tree that theoretically produces 5 different varieties of apples? Thus, the tree would have 5 different rootstocks grafted together, and would pollinate itself. I would think it would be extremely difficult for a tree like that to do well, and I doubt planting a pollinator would help.........after all there are already 5 pollinators in place. That said, if you want to try, golden delicious is an excellent all purpose pollinator, and if you have space, you could plant a red delicious also (the two will pollinate each other), then you could at worst have apples and your shade tree. Stark Brothers is an excellent source for semi dwarf apple trees.

I've got 2 apple trees that I've grown for 28 years. One is a yellow delicious and I do not remember what the other one is. I used to have a red delicious but had it removed a couple of years back due to disease. My old yellow delicious is looking pretty rough too and may have to come down soon. I sure will miss it cause it's given me many bumper crops over the years. My kids and now my grandkids have enjoyed them each fall also.
Good luck finding and growing your apple trees.
Jan

With a 5in1 tree, you ought to be seeing 5 different types of apples - unless all your grafts, or all but one variety, died out. Maybe all you have left is the rootstock, which may very well not produce very good fruits. At 25 ft tall, it sure sounds like you've just got a seedling growing.
But, it's also possible, that being in zone 8, the varieties you got on your 5in1 are not suitable for your area - I would presume you'd need some of the lower-chill selections in order to get good bloom and fruit set.
Lay off the fertilizer. Unless you've done a soil test that indicated that you need to apply a specific set of soil nutrients, most fruit trees don't really need much, if any, fertilizer. Continued or excess fertilization keeps them in a persistent 'juvenile' vegetative state, with no real impetus for them to begin flowering and fruiting.

tsmith, that little yellow-green 'June apple' was probably the old Yellow Transparent variety - we had one in the garden back in Lee Co. AL when I was a kid(in the 60s) - bet I ate 100 bushels of those things over the years. Mighty tasty at their peak, but they had about a 15 minute window of opportunity between peak quality and going mealy.