Granny Smith Apple
Pollination & Compatibility Guide
Granny Smith apple pollination requirements, bloom group 3 timing, and compatible partners. Essential guide for heat tolerance, scab, and bitter pit control.
Granny Smith is Self-Sterile (Needs 1 Partner)
Granny Smith needs at least one compatible pollinizer from bloom group 3–5 to set a reliable crop.
- Chromosome Ploidy
- Diploid (2n)
- Required Companions
- 1 Diploid Partner
- Bloom Group
- Group 4 (Mid-Spring)
- Harvest Timing
- Late (+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 3 to 5 provides matching blossom overlap.
Compatible Pollination Partners (73)
| Cultivar | Bloom Group | Overlap Type | Harvest | Primary Uses | Interactive Test |
|---|---|---|---|---|---|
| Group 4 | Full Overlap | Late ±5d delta | All-Purpose | Test Cross | |
| Group 4 | Full Overlap | Late ±5d delta | Fresh Eating | Test Cross | |
| Group 4 | Full Overlap | Late ±5d delta | All-Purpose, Storage | Test Cross | |
| Group 4 | Full Overlap | Late ±10d delta | Fresh Eating | Test Cross | |
| Group 4 | Full Overlap | Late ±10d delta | Fresh Eating | Test Cross | |
| Group 4 | Full Overlap | Late ±10d delta | Fresh Eating | Test Cross | |
| Group 4 | Full Overlap | Late ±15d delta | All-Purpose | Test Cross | |
Newtown Pippin | Group 4 | Full Overlap | Late ±15d delta | All-Purpose, Storage | Test Cross |
White Winter Pearmain | Group 4 | Full Overlap | Late ±15d delta | All-Purpose, Storage | Test Cross |
| Group 4 | Full Overlap | Late ±15d delta | All-Purpose, Cider | Test Cross | |
York Imperial | Group 4 | Full Overlap | Late ±15d delta | All-Purpose, Storage | Test Cross |
Beni Shogun | Group 4 | Full Overlap | Mid ±20d delta | Fresh Eating | Test Cross |
Tydeman's Late Orange | Group 4 | Full Overlap | Late ±20d delta | Fresh Eating | Test Cross |
| Group 4 | Full Overlap | Mid ±25d delta | All-Purpose | Test Cross | |
Melrose | Group 4 | Full Overlap | Late ±25d delta | All-Purpose, Storage | Test Cross |
Incompatible Varieties & Exclusions (15)
These varieties overlap in flowering time with Granny Smith but cannot fertilise it due to sterile pollen (triploids) or shared genetic incompatibility alleles.
Arkansas Black produces no viable pollen, so it cannot serve as a pollinizer.
Ashmead's Kernel produces no viable pollen, so it cannot serve as a pollinizer.
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.
Fall Pippin produces no viable pollen, so it cannot serve as a pollinizer.
Jonagold produces no viable pollen, so it cannot serve as a pollinizer.
Karmijn de Sonnaville produces no viable pollen, so it cannot serve as a pollinizer.
A direct parent (Granny Smith × unknown) — 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.
Orleans Reinette produces no viable pollen, so it cannot serve as a pollinizer.
Spigold produces no viable pollen, so it cannot serve as a pollinizer.
Stayman Winesap produces no viable pollen, so it cannot serve as a pollinizer.
Zabergau Reinette produces no viable pollen, so it cannot serve as a pollinizer.
Grower Commentary: Granny Smith Pollination, Chill & Crop Health
Granny Smith is a diploid, self-sterile cultivar discovered as a chance seedling in Ryde, New South Wales, Australia (c. 1868). Flowering in bloom group 3 (mid-season), it produces abundant, highly viable pollen and is an outstanding, reliable pollinizer for mid- and late-season diploid cultivars including Gala, Honeycrisp, Golden Delicious, Jonathan, and Pink Lady.
Unlike many high-chill commercial cultivars, Granny Smith has a moderate chilling requirement (~400–600 chill hours) combined with exceptional heat tolerance during the summer growing season. This makes it a staple variety in warm temperate and Mediterranean apple-growing regions where high-chill varieties suffer delayed foliation and poor fruit set.
Granny Smith hangs very late on the tree, requiring 170–190 frost-free days to reach maturity. If harvested too early, fruit remains excessively astringent; if harvested too late in high-sun environments, fruit develops undesirable yellow ground color or sunscald.
Agronomically, Granny Smith is highly susceptible to apple scab (Venturia inaequalis), powdery mildew, and bitter pit on young, vigorous trees. Regular foliar calcium applications and preventative fungicide programs are essential for commercial packout grades.
Key Orchard Considerations for Granny Smith
Low-to-moderate chill requirement and excellent heat tolerance make Granny Smith ideal for southern and Mediterranean districts.
Generates high volumes of viable diploid pollen, making it a universal partner across bloom groups 2–4.
Requires rigorous scab cover sprays in humid springs and scheduled foliar calcium sprays to prevent storage pitting.
Take Granny Smith 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 Granny Smith 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.