trainbrainmike. The people over on the Fruit Forum will definitely be able to help you with this. They are the experts.

Here is a link that might be useful: Fruit Forum

Maybe I am slightly over-exaggerating, but this question is somewhat like, "What vehicle should I drive?" The answer is complex, and, without parameters, would require a good-sized book to cover sufficiently. I would STRONGLY advise you to do your part and study a little before you ask this broad of a question in the Fruit and Orchards Forum. You could start by using the search function, found at the bottom of that forum's main pages.

Rootstock influences:
1. ultimate size of your tree
2. growth rate
3. amount and complexity of maintenance
4. ease of harvest
5. productivity
6. preciosity
7. senescence
8. hardiness
9. adaptation to different soils and soil conditions

10. drought tolerance
11. how well the tree will be anchored
12. whether the tree will need permanent or temporary support (not just how well it's anchored)
13. fruit size
14. resistance to certain diseases
15. resistance to certain pests
16. rootstock and scion graft compatibility
17. tendency to sucker
18. and I'm sure I'm leaving off at least something.

Take a little time and determine which factors are most important to you. By first identifying what information you'll need to consider, you can make your search much more efficient and insure that your conclusions are appropriate to your situation. Sure you can choose a crabapple or plain ole apple seedling and start grafting, but that is probably not the best solution in most cases. Whether it is in your case, depends.....

I am a 'newbie' to this subject. This answer, even though overly complex, shows that there are a number of things to consider. I am retired from medicine, and when a student asked a question, I had to choose between impressing him with my knowledge and further confusing him, or trying to answer in a practical way that would be helpful, not self grandizing such as this one is.

To the other posters who answered, thank you.

Nothing self-grandizing about the response at all, trainbrain. You asked a silly question (unknowingly I'm sure). Instead of pointing that out, I took my time to try to show you that the answer wasn't as simple as you wanted it to be and to help show you what types of things you needed to be thinking about to find an answer.

I certain hope your students took their inquires and studies much more seriously than you seem to take other subjects. Imagine if one walked up to you and asked, "what is the best medicine for people to take when they are sick?" I guess you'd just give them the name of the magic medicine? If you don't want real answers, why bother asking the question and wasting others' time?

Wild crabapple does work as a rootstock. The birds often drop seed where they perch or they can be found sprouting under crabapple trees in summer. Not sure where you'd find them now. If you transplant a small one with the graft below soil level, the scion will root and the rootstock will have no effect on the character of the top growth. If you wish to make a dwarf from a standard apple, you should choose dwarfing rootstock, as suggested above.

Thanks Dave_k for this answer.

Today I went to an Apple grafting class at Monticello, taught by a gentleman named Tom Burford, who is connected with the apple people at Monticello. We were shown how to do a graft, and given root stock EMLA 111 to work with, along with a choice of scions from offspring of trees planted and tended by Mr. Jefferson. We had great hands on experience and after doing one graft that was evaluated as adequate, we were given the chance to purchase root stock mentioned above for $2 each, and provided with ten scions from the Monticello trees. I have decided to plant even more orchard, and will add heritage types to the modern ones already there.

Thanks again for advice.

EMLA111 is one of the better rootstocks for many situations (especially for moderate climate zones). As mentioned earlier, there's no single rootstock that will be best for all situations, but If I had to pick one that would be best in the most situations, EMLA111 would probably be that one.

Hi,
The root stocking class sounds really nice.
I would like to put in my two cents. I live in apple tree country and I see many apple orchards and escaped apple tree's in the woods. As you know apple's from apple trees grown from seed seldom resemble the parent tree. I have seen the most gorgeous wild red apples and tasted them to find out they were terrible. At the same time I've seen gnarly discolored wild apples that were like a vitamin b12 shot and tasted out of this world. So you may ask were I am going with this.
Well , i don't care for cultivated apples from the apple industry. It seems to me they are bred for looks and a super high sugar content. If i want something that is only super sweet i can go to the sugar bowl and use that.
I'm not saying that just because an apple is ugly makes it tasty, but i am saying is to try some wild apples . you may have to go through 2 dozen tree's or more but there's always one that will be EEEExeptional. I will graft berry bushes but i really haven't done apples. For me it doesn't make much sense because apple tree's are everywhere here.

"...but i am saying is to try some wild apples."

That's a fine idea and might produce something special, but many available cultivars have been chosen mainly for quality and taste and have been chosen from thousands (not just a few dozen) types. You don't necessarily have to reinvent the wheel. There is copious amounts of info on different apples cultivars that would allow one (with a little study and possibly some sampling) to choose a really good one. Home growers might be well advised to avoid the cultivars chosen for their commercial appeal (qualities dirt_farmer is probably thinking of) and concentrate on the ones chosen for other characteristics (particularly taste, sweetness, complexity, and texture...but also things like disease resistance, ripening/harvest times, etc.). The reason there are so many apple cultivars out there is that no one is best for every situation. Even the intended use (fresh eating, baking, drying, cider, jelly, etc, etc) can make a big difference on which cultivars would be best. There have been many threads in the Fruit and Orchards Forum about choosing the best apple cultivar. There are also many documents/resources online that can be helpful. I haven't found one single resource that provides enough info on it's own, but, put together, the available online resources can be pretty good.