McIntosh Apple
Pollination & Compatibility Guide
McIntosh apple pollination guide, early bloom group 2 overlap, and partner selection. Pomological advice on cold hardiness, scab, and pre-harvest drop.
McIntosh is Self-Sterile (Needs 1 Partner)
McIntosh needs at least one compatible pollinizer from bloom group 1–3 to set a reliable crop.
- Chromosome Ploidy
- Diploid (2n)
- Required Companions
- 1 Diploid Partner
- Bloom Group
- Group 2 (Early-Spring)
- Harvest Timing
- Mid (-25d from Golden Delicious)
Flowering Period & Overlap Window
Apple flowering periods are classified into numbered bloom groups (1 through 6). A variety reliably cross-pollinates with cultivars in its own group or adjacent groups (±1 group).
Any compatible diploid apple flowering within Group 1 to 3 provides matching blossom overlap.
Compatible Pollination Partners (58)
| Cultivar | Bloom Group | Overlap Type | Harvest | Primary Uses | Interactive Test |
|---|---|---|---|---|---|
| Group 2 | Full Overlap | Early ±5d delta | Fresh Eating | Test Cross | |
| Group 2 | Full Overlap | Mid ±10d delta | All-Purpose | Test Cross | |
| Group 2 | Full Overlap | Early ±10d delta | Fresh Eating | Test Cross | |
Summerred | Group 2 | Full Overlap | Early ±10d delta | All-Purpose | Test Cross |
| Group 2 | Full Overlap | Early ±10d delta | Fresh Eating | Test Cross | |
| Group 2 | Full Overlap | Late ±15d delta | All-Purpose | Test Cross | |
Mollie's Delicious | Group 2 | Full Overlap | Early ±15d delta | Fresh Eating | Test Cross |
Sansa | Group 2 | Full Overlap | Early ±15d delta | Fresh Eating | Test Cross |
Jersey Mac | Group 2 | Full Overlap | Early ±20d delta | Fresh Eating | Test Cross |
| Group 2 | Full Overlap | Early ±20d delta | Fresh Eating | Test Cross | |
| Group 2 | Full Overlap | Late ±25d delta | Cider, All-Purpose | Test Cross | |
Winter Banana | Group 2 | Full Overlap | Late ±25d delta | All-Purpose | Test Cross |
| Group 2 | Full Overlap | Late ±30d delta | All-Purpose, Storage | Test Cross | |
Duchess of Oldenburg | Group 2 | Full Overlap | Early ±35d delta | Cooking | Test Cross |
Lodi | Group 2 | Full Overlap | Early ±45d delta | Cooking | Test Cross |
Incompatible Varieties & Exclusions (19)
These varieties overlap in flowering time with McIntosh but cannot fertilise it due to sterile pollen (triploids) or shared genetic incompatibility alleles.
Baldwin produces no viable pollen, so it cannot serve as a pollinizer.
Belle de Boskoop produces no viable pollen, so it cannot serve as a pollinizer.
Blenheim Orange produces no viable pollen, so it cannot serve as a pollinizer.
Bramley's Seedling produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (McIntosh × Longfield) of the cultivar this is a sport of — genetically the same tree, so roughly half the pollen is non-functional and it is not a reliable partner.
A direct parent (Ben Davis × McIntosh) — roughly half the pollen is non-functional, so it is not a reliable partner.
A direct parent (McIntosh × Red Delicious) — roughly half the pollen is non-functional, so it is not a reliable partner.
Fall Pippin produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (McIntosh × Longfield) — roughly half the pollen is non-functional, so it is not a reliable partner.
Gravenstein produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (Jonathan × McIntosh) — roughly half the pollen is non-functional, so it is not a reliable partner.
Karmijn de Sonnaville produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (Jersey Black × McIntosh) — roughly half the pollen is non-functional, so it is not a reliable partner.
Mutsu (Crispin) produces no viable pollen, so it cannot serve as a pollinizer.
Ribston Pippin produces no viable pollen, so it cannot serve as a pollinizer.
Roxbury Russet produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (McIntosh × Newtown Pippin (Newtown Pippin side disputed — see sourceNote)) — roughly half the pollen is non-functional, so it is not a reliable partner.
Spigold produces no viable pollen, so it cannot serve as a pollinizer.
Tompkins King produces no viable pollen, so it cannot serve as a pollinizer.
Grower Commentary: McIntosh Early Bloom, Cold Hardiness & Harvest Drop
McIntosh is an early-flowering diploid cultivar (bloom group 2) discovered by John McIntosh in Dundela, Ontario (c. 1811). Because of its early blossoming window, pairing McIntosh with companion cultivars from bloom groups 1–3 (such as Idared, Discovery, Spartan, Cortland, or early-flowering crabapples like Dolgo) is critical to ensure overlapping pollen shed.
The 'Mac' family lineage: McIntosh is the matriarch of the North American cold-climate apple industry, serving as parent to Cortland (Ben Davis × McIntosh), Empire (McIntosh × Red Delicious), Macoun (Jersey Black × McIntosh), Spartan, Jonamac, and Fireside. Because all inherit McIntosh maternal S-alleles, none of these offspring can serve as reliable sole cross-pollinizers for McIntosh.
Agronomically, McIntosh displays extraordinary cold hardiness, surviving deep winter freezes down to USDA Zone 3b. However, it is notoriously susceptible to apple scab (Venturia inaequalis) on both leaves and fruit, demanding rigorous early-season fungicide cover.
Pre-harvest fruit drop is the defining management challenge with McIntosh. As fruit ripens in early autumn, ethylene synthesis triggers rapid abscission layer formation, potentially dropping 20–50% of the crop before commercial color grade is achieved. Commercial growers rely on harvest timing and plant growth regulators (such as AVG or NAA) to manage drop.
Key Orchard Considerations for McIntosh
Pair exclusively with early-blooming companions (groups 1–3) to guarantee full floral overlap during early spring weather.
Do not rely on direct descendants including Cortland, Empire, Macoun, Spartan, or Jonamac as sole cross-pollinizers.
Monitor fruit starch conversion closely and apply stop-drop growth regulators or execute multi-pass pickings to prevent drop loss.
Take McIntosh from Planning to Planting
Use Kropigo's free browser tools to model your block density, tree counts, and pollinizer rows, then maintain permanent orchard records row by row.
Pollination Checker
Check McIntosh against supported cultivars with compatible flowering and pollination data.
Commercial Block Planner
Calculate high-density tree spacing, row geometry, and establishment costs.
Block Record Keeping
Track pruning, chemical thinning, and harvest tallies block by block from the orchard.