Short answer
The cultivar decides the fruit. The rootstock decides the tree: how big it gets, whether it needs a post for life, and part of its disease resistance.
For apples: G.11 or G.214 if you can give a permanent post; G.969 for a tree that stands without support on open or poorer ground. For pears, OHxF 333, 87 and 97 run smallest to largest.
The tables on this page give the expected size for each stock.
On a grafted tree the rootstock shapes final size, whether it needs support for life, and part of its disease resistance. It is the choice customers think least about and live with longest.
Choosing, in order
- Measure the space at maturity, not at planting
- Decide whether a permanent post or trellis is practicable. If not, rule out G.11 and G.214
- Assess soil depth and drainage. Thin or dry ground favors the more vigorous stocks
- Check the cultivar's own vigor. The rootstock sets the range; the scion places the tree within it
- Scion. The named cultivar. It decides the fruit.
- Graft union. Where scion and rootstock were joined.
- Rootstock. Decides size, anchorage and part of the hardiness.
- Root collar. Where stem meets root, at the surface of the mix.
- Growing mix. Peat-based growing medium.
- Root system. Trained downward by the container rather than circling.
- Air-pruned container. Deep, ribbed walls that stop roots circling.
1. What the rootstock influences
The variety decides the fruit. The rootstock supplies the root system and strongly influences the tree: mature height, anchorage, tolerance of wet or dry soil, and resistance to some root diseases. Effects vary with the scion genotype and the site, but two trees of the same apple on different roots are different propositions in the garden.
Iowa State's working figures: dwarf apple about 10 feet, semi-dwarf about 15, standard at least 20. Dwarf and semi-dwarf trees are easier to prune, spray and harvest and fit a small garden. The trade-off is anchorage.
Why a rootstock controls the size of a tree it does not grow
A dwarfing rootstock restricts the flow of water, nutrients and root-produced hormones to the scion, and alters the movement of auxin downward from the shoots. The scion responds with shorter internodes, earlier cessation of shoot growth each season, and an earlier switch from vegetative growth to flower bud formation.
The same restriction is why dwarfing stocks are shallow-rooted, drought-sensitive and poorly anchored, and why they need a post. Small size and weak anchorage are one trait seen from two sides, not separate traits that happen to coincide.
2. Rootstock reference: what we graft onto what
Every grafted tree we sell uses one of the stocks below. Where a category offers a choice, you pick the rootstock in the selector on the product page; the tables below give the expected size for each.
| Category | Rootstock options |
|---|---|
| Apples | G.11 · G.214 · G.969 |
| Pears, medlars, Shipova, Pyronia | OHxF 333 · OHxF 87 · OHxF 97 |
| Quince | BA 29C Provence quince |
| Peaches and nectarines | Krymsk 86 |
| Almonds | Krymsk 86 |
| Cherries, sweet and tart | Mazzard |
| European, Japanese and hybrid plums | Myro 29C (Lantz also on American plum) |
| American plums and apricots | American plum |
| Persimmons | 90-chromosome American persimmon |
| Mulberries | Hybrid mulberry |
| Pawpaws | Pawpaw seedling |
| Pecan | Northern pecan |
| Heartnut | Black walnut |
| Che | Osage orange |
| Chestnuts | None. Seed grown on their own roots |
| Citrus | Flying Dragon trifoliate orange |
| Figs, kiwi | None. Cutting grown, own roots |
| Scionwood | None. You supply the rootstock |
3. Apple rootstocks in detail
All three are Geneva series stocks, bred at Cornell for fire blight resistance and cold hardiness, which is why we use them rather than the older Malling stocks. A fire blight infection that reaches a susceptible rootstock kills the whole tree; on a Geneva stock it stays a pruning job. See the fire blight guide.
| Stock | Mature size | Support | Best for |
|---|---|---|---|
| G.11 | Dwarf, roughly 8 to 10 ft | Permanent. A post for life, not a stake for two years | Small gardens, espalier, trellised rows, maximum variety count in minimum space |
| G.214 | Dwarf, similar in size to G.11, roughly 8 to 10 ft | Permanent. A post for life | Small gardens; an alternative to G.11 of similar size |
| G.969 | Larger semi-dwarf, roughly 15 to 18 ft | Stands without support | Poorer sites, exposed ground, long-lived trees, anywhere you will not be maintaining a support |
One variety-specific note. Finkenwerder Herbstprinz tends to produce oversized, soft fruit on dwarfing stock, which loses the firmness and keeping quality it is grown for. Take G.969 for that one.
4. Pear rootstocks in detail
The OHxF series comes from an Old Home crossed with Farmingdale program selected for fire blight resistance, which matters more on pears than almost anything else.
| Stock | Mature size | Notes |
|---|---|---|
| OHxF 333 | Most size-controlling, about half to two thirds of standard (WSU, WVU) | The closest thing to a dwarf pear we offer. Good where space is tight |
| OHxF 87 | Slightly smaller than seedling, about 85 to 90 percent of standard (WVU Extension) | A near-standard tree for a garden with room |
| OHxF 97 | Full size, similar to seedling, strongest anchorage | Standard-scale tree, best on exposed or poorer sites |
We graft medlars, Shipova and Pyronia onto the same pear stocks, so the same size logic applies to them.
5. Stone fruit rootstocks
| Stock | Used for | Why |
|---|---|---|
| Krymsk 86 | Peaches, nectarines, almonds | A peach and plum hybrid (Prunus persica × P. cerasifera) from the Krasnodar region of Russia. Vigorous, well anchored and compatible with peach, nectarine, almond, plum and apricot. Its roots are susceptible to root-knot nematode, so avoid sandy, nematode-prone ground (UC Cooperative Extension). Every peach, nectarine and almond we graft is on Krymsk 86 |
| Myro 29C | European, Japanese and hybrid plums | Tolerant of heavier soils than most plum stocks |
| American plum | Hybrid plums, apricots | The hardiest stock we offer. Native, and suckers more than the others |
| Mazzard | Sweet and tart cherries | Standard size, long-lived, well anchored |
6. Specialty stocks
| Stock | Used for | Why it matters |
|---|---|---|
| 90-chromosome American persimmon | All persimmons | The chromosome count is not a detail. 60-chromosome stock is not reliably compatible with northern scions, and a mismatch shows up as delayed graft failure years later |
| BA 29C Provence quince | Quince | A Provence-type quince clone selected in France. Quince grafted on quince is the same species, so the graft union is fully compatible. Quince roots are less cold-hardy than most stocks, so in zone 5 and colder plant with the graft union low and mulch the root zone |
| Hybrid mulberry | Mulberries | Vigor and hardiness |
| Pawpaw seedling | Pawpaws | No clonal pawpaw stock exists in commerce. Seedling is the only option |
| Northern pecan | Pecan | Selected from the northern end of the species range for season length |
| Black walnut | Heartnut | Compatible Juglans stock, and hardy |
| Osage orange | Che | Both are Maclura. Osage orange is hardy and widely available |
7. Site factors
Rootstock performance is modified by the ground it grows in. Published size figures assume a moderate, well-drained soil of reasonable depth.
- Soil depth. Dwarfing stocks are shallow-rooted and poorly suited to thin soils or sites without irrigation. On such ground a more vigorous stock compensates.
- Drainage. No stock we offer tolerates standing water. American plum takes heavier and wetter ground than the peach stocks, which is part of why we use it under apricots.
- Exposure. A dwarfing stock on an open site needs permanent support, not temporary staking. A dwarf tree carrying a full crop in a wind event will lean or lift without it.
- Replant ground. Where an apple has grown before, specific apple replant disease can slow establishment. G.969 tolerates replant sites better than the more dwarfing options.
- Scion vigor. A naturally vigorous cultivar on G.11 makes a larger tree than a spur-type cultivar on the same stock.
8. An unusual one worth knowing
Carrick pear is quince-compatible, which most European pears are not. A four-season Brazilian trial found quince 'Portugal' gave both the highest yield and the strongest dwarfing. We graft ours on OHxF, but if you ever want a truly small pear tree, Carrick is the variety that allows it.
9. If you are grafting yourself
We sell scionwood in 4, 6 and 8 stick bundles with no rootstock, so you supply your own. The table above tells you what we would put each variety on.
Size figures are typical performance on moderate soils and vary with site, moisture, scion vigor and training. Published values differ between sources.
References
- Iowa State University Extension and Outreach, Yard and Garden: Growing Fruit Trees
- Cornell University and USDA-ARS Geneva apple rootstock breeding program publications
- eXtension Apples, Apple Rootstock Info: G.214, citing Penn State Extension, Apple Rootstocks: Capabilities and Limitations
- Oregon State University and the USDA Corvallis repository, for the OHxF pear series
- West Virginia University Extension, Pear Rootstocks
- Washington State University Tree Fruit, Pear Rootstocks
- Michigan State University and University of Minnesota Extension, for stone fruit rootstock performance and root hardiness
- Connell, J. Observations on Krymsk 86. University of California Cooperative Extension, Butte County
- Webster, A.D. and Wertheim, S.J. 2003. Apple rootstocks. In: Ferree, D.C. and Warrington, I.J. (eds), Apples: Botany, Production and Uses. CABI Publishing
- dos Santos-Pereira, I. et al. 2021. Cyanogenic glycosides content as graft compatibility indicator in pear/quince combinations. Acta Agronómica 70(1): 73 to 81