Standards are trees that are grafted to seedling rootstocks (grown from seed); most make full- sized trees when mature- (12 to 20 ft tall in the north and 20 to 30 ft tall in warmer climates). The don't require staking, survive neglect and abuse better, live 60 to 120 years or so, are said to be better adapted to short growing seasons, and, (with the possible exception of trees with baccata rootstocks which produce a somewhat smaller tree), can have branches trained to grow beyond the reach of deer and moose. Standards live very long lives and produce trees that your kids and grandkids can climb and fondly remember when they are grown. More on Standards

Dwarf trees are small when mature, from 5 to 12 feet tall. Trees are dwarfed by being grafted to dwarfing rootstocks propagated by cuttings, layers, or tissue culture. Although dwarfs are considered more "efficient" at producing fruit, that is they yield more fruit proportionate to branch and more fruit per acre, they do require more care in weeding, staking, and irrigating and offer little margin of error for neglect or mistakes. (Irrigation for dwarfs is not always necessary for homegrowers once the trees become established). Almost all dwarf stock needs to be staked. Dwarf trees allow more varieties to be planted in a smaller space, produce more fruit per area, are easier to harvest, spray, and protect from insects, make good stocks for espalier trees (trees pruned to conform to patterns or shapes), and in zone 5 and maybe 4, will bear their first crops one to 3 years earlier than standards. (See Growing Dwarf Trees in Zone 3.) They are an excellent choice in "lawned" yards and areas where there isn't space for a full-sized tree, where they in sight and in mind, and where there is little weed competition. And although the trees are smaller, the fruits are full sized.

Interstem trees: Interstem trees combine advantages of a standard tree (resistance to neglect, no staking required) and advantages of dwarf trees (small size, early to bear). Interstems on 111, 118, ranetka, and even antonovka are by far the best choice for low water use areas since they are even more drought tolerant than full sized trees because they have full sized roots but dwarfed trunks so it has fewer leaves to support. During stress, their roots are far superior and much more capable of providing for a high yielding dwarf tree.Their main drawback is suckering if the tree is not planted at the right depth. (cover the rootstock/interstem union by two or three inches). Recent experiments show that Bud 9 interstem (on antonovka) is even more yield efficient than trees on dwarfing roots. Interstems are grafted twice, one year apart, this is why they are more expensive. (First the interstem- a 6- 12" stem piece from a dwarf rootstock, is grafted to a tough rootstock such as MM 111 or antonovka, and then the variety, [such as Ashmead's Kernel], is grafted to the interstem.) I do not know if they would bear earlier than a standard in zone 3 but I would suspect that they would have a better chance than a dwarf on its own roots.

According to the Pennsylvania State University, "Interstems are becoming increasingly popular in Pennsylvania orchards. Size control is directly related to the length of the intermediate stem piece. Interstem apple trees offer a strong root system while reducing the size of the overall tree. Interstem trees should be planted so that a portion of the interstem is buried."

Individual Rootstocks
See Rootstock Tables for a quick reference.

Antonovka: Varieties grafted to antonovka produce standard (full- sized, trees. Antonovka is unusual in that it has a pronounced taproot (carrot- shaped, large central vertical root). It has a wide range of soil adaptability. It is vigorous and well- suited for short seasons. Although its branches are winter hardy to beyond 50 below zero, its crown area (part of trunk/root near ground level) is hardy to about 40 below if the soil is moist. If the soil is dry at 40 below with no snow cover, the tree could winterkill. (Has done so with disastrous results in AK). Antonovka devotes most of its early growth to establishing its taproot. After many years it will then send out more feeder roots.

Ranetka: Produces standard or full-sized trees. Probably slightly less adapted to wetter soil than antonovka but excels in well- drained and light soils putting out the same growth in 2 years that which takes antonovka and baccata 3 years. Extremely winter hardy and according to Claire Lammers, it can take 40 below with dry soil, no snow. It is vigorous and well adapted to short seasons. Ungrafted ranetka begins growth 10 days before antonovka in the spring (first apple to have leaves in the spring) and grows longer into the fall. Said to be compatible with a wider range of varieties than baccata and so far seeming to be just as compatible (with modern varieties) as antonovka (except for Rescue Crab)

Baccata: It is unquestionably the hardiest rootstock, in both branch and crown. Also called "Siberian Crab".According to Hanson, Bulletin 50, p. 7 (if I recall, in the ND Ag Bulletins): "If the soil is moist in fall, ordinary apple seedling will not root kill; if dry, it will. But a Siberian crab root won't die even on dry soil". I have heard of a fellow who left his potted baccata out all winter in 40 below zero weather without winterkill. (Most apple roots are said to kill at 19 degrees F whereas antonovka survives 14 degrees F) ."Produces a mature tree that is about 25% smaller than those grafted to antonovka or ranetka and is said to bear 2 years earlier. Adapted to a wide range of soils. Its compatibility with apples from warmer zones which don't have as much baccata in their parentage has been questioned. (Most modern apples have, to varying degrees, some baccata in their genes lending them cold hardiness.) One grower- Bernie Nikolai, has told me that there is no evidence of compatibility problems with any of the apples he's grafted. (He has mostly super cold- hardy apples but also some from warmer zones.

Bud 9: Produces a dwarf tree, 6 to 10 ft at maturity. Requires staking. In zone 5 trees grafted to Bud 9 should bear in 3 to 5 years It is questionable whether or not it will induce early bearing in zone 3. See Dwarf Trees in Zone 3. Adapted to a wide range of soils, proving to have larger fruits than other full dwarfs during drought years. Even more resistant to "collar rot" than M9. About as winter hardy as antononka. No compatibility problems reported.

Bud 490: Precocious and according to Treco, "induces early heavy production". Survived well with no snow and 30 below C. Drought resistant. Approximately 80 percent of standard Generally free standing, susceptible to fireblight, crown and root rots, extremely winter hardy according to some reports. Resistant to apple union necrosis and decline disease.

MM 111: 111 is truly amazing in sandy soil and may be your best bet with pure sand even in zone 3 because although the trunk and branches of 111 are not hardy to beyond -35 F, by burying the graft union you can protect the tender trunk even in the coldest environments, giving you the very best rootstock in sandy soil (and avoiding the burr knot problem). If you don't get at least a few inches of snow by January, you could get some root damage especially if the soil is dry. However, by burying the graft union, the scion should root thus giving some added insurance against life- threatening frost damage to roots.
MM 111 is normally freestanding, requiring no staking. Cultivars grafted directly to 111 produce trees that are semi- dwarf in size, in zone five, the final tree size would be between 15 and 20 ft tall. It does not induce early bearing like a dwarf but does bring a tree to its mature height faster. In Menominee, WI, Honeycrisp, a low vigor variety, grafted to 111 has begun to bear in 4 years. In addition to performing well in light, poor soil, 111 has also performed better in our heavy shallow soil, outgrowing trees on antonovka by nearly twice the rate.

Bud 9/111 Interstem: Produces a dwarf tree that is free standing except in extremely windy sites, extremely drought tolerant, and, according to a study on interstems with antonovka as the understock, interstems have shown to be even more yield efficient than trees on dwarf stocks. Known to increase suckering as it grows to bearing age. To discourage suckering, bury the interstem/rootstock graft union by a few inches. Hardy to about 40 below if you bury the 111 roots completely. (This is recommended anyway except on poorly drained soil.) May not be the best choice in zone 3, but worthy of trial for poor dry soil and a dwarfing stock that may do better due to its more vigorous roots. May be the best choice for semiarid regions.