Red Clapp's Favorite Pear
Pollination & Compatibility Guide
Red Clapp's Favorite (Starkrimson) pear pollination guide: summer harvest window, diploid bloom overlap, fire blight care, and Quince interstem requirements.
Red Clapp's Favorite is Self-Sterile (Needs 1 Diploid Partner)
Red Clapp's Favorite needs at least one compatible pollinizer from bloom group 2–4 to set a reliable crop.
- Chromosome Ploidy
- Diploid (2n)
- Required Companions
- 1 Diploid Partner
- Bloom Group
- Group 3 (Early-Spring)
- Harvest Timing
- Mid (-28d 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 2 to 4 provides matching blossom overlap.
Compatible Pollination Partners (22)
| Cultivar | Bloom Group | Overlap Type | Harvest | Primary Uses | Interactive Test |
|---|---|---|---|---|---|
| Group 3 | Full Overlap | Early ±3d delta | Fresh Eating | Test Cross | |
| Group 3 | Full Overlap | Mid ±14d delta | Fresh Eating, Canning | Test Cross | |
| Group 3 | Full Overlap | Early ±14d delta | Fresh Eating, Canning | 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, Cooking | Test Cross | |
| Group 3 | Full Overlap | Late ±28d delta | Fresh Eating, Cooking | Test Cross | |
| Group 3 | Full Overlap | Late ±42d delta | Fresh Eating, Baking | Test Cross | |
| Group 3 | Full Overlap | Late ±42d delta | Fresh Eating | Test Cross | |
| Group 3 | Full Overlap | Mid ±42d delta | Fresh Eating, Storage | Test Cross | |
| Group 3 | Full Overlap | Late ±42d delta | Fresh Eating | Test Cross | |
| Group 3 | Full Overlap | Late ±49d delta | Fresh Eating, Canning | Test Cross | |
| Group 2 | Full Overlap | Early ±3d delta | Fresh Eating | Test Cross | |
| Group 2 | Full Overlap | Early ±7d delta | Fresh Eating, Canning | Test Cross | |
| Group 2 | Full Overlap | Early ±8d delta | Canning, Jelly | Test Cross |
Incompatible Varieties & Exclusions (4)
These pear varieties overlap in flowering time with Red Clapp's Favorite 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.
Luscious 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: Early Summer Colour, Pollination Alignment & Ripening Care
A natural red sport of the historic American variety Clapp's Favorite, Red Clapp's Favorite (frequently sold as Starkrimson) is prized for its solid crimson-red skin. The fruit is large, pyriform, and visually striking, offering juicy, fine-grained, sweet melting flesh that opens the summer pear harvest season.
Red Clapp's is a self-incompatible diploid blooming in Bloom Group 3. It overlaps readily with early-to-midseason diploids including Bartlett, Moonglow, and Conference. Because it produces high quantities of viable pollen, it functions as a dependable reciprocal donor for adjacent cultivars in the block.
Orchardists value Red Clapp's for its vigorous, broad growth habit and high initial yield. However, fruit firmness drops rapidly as maturity approaches, demanding tight harvest scheduling to prevent over-maturity on the tree. Orchard managers typically plan multiple selective pickings across the block rather than a single strip harvest, taking the largest, well-coloured fruit first to allow smaller pears to gain size on the branch before total canopy softening.
Key Orchard Considerations for Red Clapp's Favorite
Shows poor direct affinity with Quince rootstocks; grafts made directly are prone to delayed failure. Growers should specify OHxF 87 or OHxF 97 rootstocks, or employ a Beurré Hardy interstem if dwarfing Quince stocks are required.
Highly susceptible to fire blight. Because early summer growth flushes coincide with humid weather, strict bactericide coverage during bloom and post-bloom shoot elongation is critical.
Harvested very early—typically two to three weeks before Bartlett. Fruit must be picked firm and ripened off the tree; allowing fruit to ripen on the branch leads to rapid core breakdown and mealiness.
Take Red Clapp's Favorite 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 Red Clapp's Favorite 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.