Have 2 main traits.
1) Time/Age- Heirlooms are seeds that have been around for 50+ years (though some might argue an older period than that). They are passed down from one generation to another.
2) Are open pollinated.
This is the process of pollination by insects, animals, wind and other natural means.
The Seeds of these plants will produce new generations of these plants. However, there will be uncontrolled breeding with these plants and thus there will be
Pros
- Greater variation
- Seeds can be saved and passed on to the next generation
Is controlled pollination through human intervention.
Hybrid Seeds are made by crossing varieties.
Pros
- Hybrid Vigor- generation one tends to produce plants, etc. with superior qualities ie: grows better, produces greater quantities, earlier ripening,etc.
- The need to purchase new seeds every year, because seeds produced are not genetically stable and can't be saved for future uses.