The lower portion of the a fruit tree is called the rootstock. This is the portion of the tree that has been grafted over to a specific variety. Different rootstock's provide opportunities for everyone to enjoy the thrill of growing your own fruit. If you have limited growing space you could choose a dwarf rootstock that limits the height of your tree to as little as 5 feet! There are possibilities and sizes to match almost any need. Lastly, pruning has a great impact on size, if you need to maintain a certain height then also prune in the summer.
NOTE: Mature tree size is determined by the rootstock in combination with the vigor of the variety. For example, a Northern Spy or Gravenstein on a semidwarf rootstock will be larger than a Jonathan or Idared on the same rootstock. Research has shown that the growth of a tree composed of two parts is a compromise between the rootstock and the scion.
It is important for the relationship between scion and rootstock to be close. The botanical classification can only serve as a rough guide being founded strictly on reproduction parts of plants. Something greater than kinship is required for a graft to be successful and that depends on similarity of vegetative characteristics. For example, pears (Pyrus communis) will form a lasting union with hawthorn (Crataegus oxyacantha) and medlar (Mespilus germanica), but the joining of species within a given genus is much more common.
Symptoms of incompatibility are either immediately visible when the graft simply fails to take but just as often are not apparent for many years afterwards. The most common evidence later on is that the composite tree breaks off at the graft. The problem of incompatibility might be exacerbated by multiple grafts.
MM111 (Semidwarf) Produces a tree 70-80% of standard size. Growth tends to be upright with wide crotch angles. Well anchored, resistant to drought and high soil temperatures. Excellent semi dwarf rootstock for heavy soils. Resistant to wooly aphids. Disadvantage is burrknotting. Bears fruit 3 to 4 years and grows to 15 to 18 feet.
M9 (Dwarf) Produces a tree 30-40% of standard size. Resistant to collar rot and rarely produces suckers. Withstands heavy soils and wet conditions. Disadvantage is that roots tend to be brittle, so trees on this rootstock require staking throughout their entire life. Not suited to dry, light soils. Bears fruit 1-2 years and grows to 6-9 feet.
EMLA 27 Can be maintained at only four to six feet in height. It is well suited for growing in a container of a small yard. Trees grafted on EMLA 27 bear early and heavily. They should be staked.
EMLA 7 Produces a semi-dwarf tree 11 to 16 feet tall. Does well in most soils annd produces fruit in about three to four years. Does well in even wet soils, but is inclined to suckering wherever planted.
EMLA 26 Will produce a dwarf tree from 8 to 14 feet. Des well in most soils, producing fruit in about two to three years. Needs staking in windy sites and is relatively sucker free. This is the rootstock I have chosen for this class.
Standard Produces a strong well anchored tree. Trees are vigorous and tolerant of drought and wet soils. Bears fruit between 6-12 years and grows to 20-25 feet.
OHxF 333 (Old Home and Farmingdale) Produces a tree 50-70% of standard size. Resistant to fire blight and pear decline. Does not sucker and developes hardy well anchored tree. Tolerates a broad range of soils. Bears fruit between 3-4 years and grows to 12-16 feet.
STONE FRUITS ROOTSTOCK
Lovell Produces a strong well anchored tree with resistance to bacterial canker. Tolerates cold and wet soils. Susceptible to nematodes in sandy soil. Bears fruit 2-3 years and grows to 15-18 feet.
Mariana Produces a shallow rooted tree allowing greater tolerance to wet soils. Resistant to oak root fungus, some nematodes and brown line. Slightly dwarfing for plums and apricots. Bears fruit 2-3 years and grows to 15 – 18 feet.
Mazzard Cherry rootstock that produces a large tree well anchored that tolerates heavy soil. Resistant to oak root fungus and root knot nematodes. Bears fruit 5-6 years and grows to 20-35 feet.
Mahaleb Cherry rootstock that produces a standard size tree for sour cherries and slightly dwarfing for sweet cherries. Prefers well drained soils. Resistant to crown gall, bacterial canker, and some nematodes. Hardy to zone 4. Bears fruit 3-5 years and grows to 20-30 feet.
Colt Cherry rootstock that produces wide branched angles on a well anchored tree. Tree is 70-80% of standard. Resistance to bacterial canker and crown gall. Hardy to -10 F. Bears fruit 3-4 years and grows 15-20 feet.
G.M. 61/1 Cherry rootstock that produces a open, moderately vigorous, frost resistant, few suckers and thrives in heavier soil. Bears fruit in 3-4 years and grows to 8-12 feet.
Myrobalan Produces a tree with great anchorage and tolerant of wet soils. Susceptible to oak root fungus and nematodes. Bears fruit in 2-3 years and grows to 12-18 feet.
Nemaguard Produces a vigorous tree in well drained soils. Susceptible to wet feet. Redundant phrase, but needs to be said, nematode resistant. Bears fruit in 2-3 years and grows to 12-18 feet.
Citation Produces a tree 50-65% of standard in peaches and 75% of standard in apricots and plums. Strong well anchored. Resistant to nematodes, tolerant of wet soils, no suckers, and cold tolerant. (zone 4). Bears fruit in 2-3 years and grows to 12-16 feet.
Almond Resistant to bacterial canker and nematodes. Bears fruit 3-4 years and grows to 10-14 feet.
Pecan Bears fruit 5-8 years and grows to 30-60 feet.
Walnut Bears fruit 5-10 years and grows to 18-30 feet
From the Raintree Nursery Catalog...