Potomac Pear
Pollination & Compatibility Guide
Potomac pear pollination guide: Moonglow × Anjou pedigree, Bloom Group 4 timing, fire blight immunity, and winter storage.
Potomac is Self-Sterile (Needs 1 Diploid Partner)
Potomac 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
- Mid (+14d from Conference)
Flowering Period & Overlap Window
Pear flowering periods are compressed into numbered bloom groups (1 through 4). Cross-pollination requires overlapping blossom timing between genetically compatible cultivars, with Asian pears flowering 7–14 days ahead of mid-season European varieties.
Any compatible diploid pear flowering within Group 3 to 5 provides matching blossom overlap.
Compatible Pollination Partners (17)
| Cultivar | Bloom Group | Overlap Type | Harvest | Primary Uses | Interactive Test |
|---|---|---|---|---|---|
| Group 4 | Full Overlap | Late Concurrent (±0d) | Fresh Eating, Cooking | Test Cross | |
| Group 4 | Full Overlap | Late Concurrent (±0d) | Fresh Eating | Test Cross | |
| Group 4 | Full Overlap | Late Concurrent (±0d) | Canning, Cooking | Test Cross | |
| Group 4 | Full Overlap | Late ±21d delta | Fresh Eating, Storage | Test Cross | |
| Group 3 | Full Overlap | Late Concurrent (±0d) | Fresh Eating, Baking | Test Cross | |
| Group 3 | Full Overlap | Late Concurrent (±0d) | Fresh Eating | Test Cross | |
| Group 3 | Full Overlap | Mid Concurrent (±0d) | Fresh Eating, Storage | Test Cross | |
| Group 3 | Full Overlap | Late Concurrent (±0d) | Fresh Eating | Test Cross | |
| Group 3 | Full Overlap | Late ±7d delta | Fresh Eating, Canning | Test Cross | |
| Group 3 | Full Overlap | Mid ±14d delta | Fresh Eating, Cooking | Test Cross | |
| Group 3 | Full Overlap | Late ±14d delta | Fresh Eating, Cooking | Test Cross | |
| Group 3 | Full Overlap | Late ±21d delta | Fresh Eating, Canning | Test Cross | |
| Group 3 | Full Overlap | Mid ±21d delta | Fresh Eating, Canning | Test Cross | |
| Group 3 | Full Overlap | Mid ±28d delta | Fresh Eating, Canning | Test Cross | |
| Group 3 | Full Overlap | Early ±28d delta | Fresh Eating, Canning | Test Cross |
Incompatible Varieties & Exclusions (3)
These pear varieties overlap in flowering time with Potomac but cannot fertilise it due to non-viable pollen (male-sterile diploids), direct parentage exclusions, or shared incompatibility alleles.
Gourmet produces no viable pollen, so it cannot serve as a pollinizer.
Magness produces no viable pollen, so it cannot serve as a pollinizer.
Warren produces no viable pollen, so it cannot serve as a pollinizer.
Pomological Assessment: Anjou Flavour Profile, Blight Resistance & Late Bloom
Released in 2003 by the USDA-ARS and Ohio State University from a cross between Moonglow and Beurré d'Anjou, Potomac delivers the rich flavour and dense, buttery texture of Anjou combined with elite fire blight resistance. The fruit is medium-to-large, glossy light green, and stores exceptionally well.
Potomac is a diploid cultivar flowering in Bloom Group 4 (late mid-season). It requires companion diploids flowering in the late bloom window, such as Blake's Pride, Comice, Harrow Sweet, or Anjou. Potomac produces viable pollen and serves as a dependable reciprocal pollinizer.
Tree structure is moderately upright and vigorous, forming well-spaced spurs along lateral branches. Commercial growers benefit from its strong disease profile, which allows reduced chemical intervention while maintaining excellent fruit finish and long-term tree health. The fruit exhibits excellent handling durability, resisting mechanical scuffing during picking and bin transit far better than classic Comice. Potomac's robust canopy structure and low blight susceptibility make it a standout choice for sustainable orchard plantings.
Key Orchard Considerations for Potomac
Shows excellent affinity and precocity on OHxF 87 rootstock. The tree forms a well-spaced, upright-spreading canopy that is straightforward to train into central-leader systems.
High genetic resistance to fire blight inherited from its Moonglow parentage, making it a sustainable alternative to Anjou in blight-prone commercial districts.
Harvested mid-to-late season (approximately two weeks after Bartlett). Stores for eight to twelve weeks at 0°C and ripens to a rich sub-acid flavour without superficial scald.
Take Potomac 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 Potomac 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.