Sam Norris 7 (SN-7) is a legendary and exceptionally rare pawpaw clone developed by amateur breeder Sam Norris of Owensboro, Kentucky. It is highly valued in breeding programs, most notably by Jerry Lehman, as a potent genetic source for jumbo fruit size. Its likely status as a tetraploid (due to colchicine induction) makes it a unique tool for hybridization, though this same trait complicates its use as a standard orchard variety. It is primarily available through limited scionwood offerings for serious collectors and breeders.
SN-7 emerged from Sam Norris's experimental work in Kentucky, where he used colchicine to induce polyploidy in pawpaws. This selection was adopted by Jerry Lehman, who used it to anchor many of his large-fruited breeding lines. While well-known in specialist circles, SN-7 remains a collectors' item rather than a commercial cultivar.
Size: The defining trait of SN-7 and its offspring is massive fruit size. While average weights aren't officially documented, individual specimens have been reported to reach a staggering 631–704 g (1.4–1.5 lbs), placing them among the largest pawpaws ever recorded. Flavor: Descendants of SN-7 are noted for their pleasing taste and smooth texture, though the precise flavor profile is often shaped by the other parent in the cross.
Yield: Public data on the yield of SN-7 as a standalone tree is sparse. Growers interested in productivity are encouraged to monitor grafted trees in trial settings. Ripening: While exact dates vary by climate, SN-7 follows the general pattern of mid-to-late season varieties, typically ripening in September.
Though documentation is minimal, SN-7 is expected to handle the environmental conditions typical of its Kentucky origin, likely thriving in USDA Zones 5–8.
Like most pawpaws, SN-7 requires cross-pollination. Its suspected tetraploid nature is a critical factor; crossing a tetraploid with a diploid can lead to triploid offspring, which often have significantly fewer seeds. This makes SN-7 an invaluable tool for developing low-seed "seedless" varieties, but it requires careful planning to ensure compatible pollination partners are present.
SN-7 is virtually never found as a potted nursery tree in general commerce. Its existence in orchards today is almost entirely the result of hobbyists and specialist nurseries sharing scionwood for grafting.
Much of what is known about SN-7 comes from informal sources, forum discussions, and nursery catalogs rather than academic trials. Metrics like °Brix or specific seed percentages are not widely available. Furthermore, growers should be cautious of potential nomenclature confusion, as several "Sam Norris" lines exist.
Sam Norris 7 is for the "Pawpaw Architect." It is a foundational genetic block that has shaped the look of modern large-fruited hybrids. For the breeder or dedicated collector, SN-7 offers a glimpse into the extremes of pawpaw genetics, providing a pathway toward fruits of unprecedented size and reduced seed counts.
| Indicator | Cultivar Metric |
|---|---|
| Heritage Line | Sam Norris Selection (Lehman Breeding Source) |
| Average Fruit Mass | Jumbo (Reports of 631–704 g) |
| Breeding Status | Genetic Source / Selection Source |
| Flavor Class | High Quality (Offspring) |
| Ripening Window | Likely Mid-to-Late (September) |
| Hardiness Grade | USDA Zones 5–8 (Estimated) |
| Genetics | Likely Tetraploid |
| Availability | Extremely Rare / Scionwood Only |