A seed zone is an area within which seeds can be collected, and the resulting plants can be planted, with a low risk of the plants being poorly adapted to the new location. Generally, it is better to source seeds as close to the intended planting location as possible, but this can often be challenging. Sometimes seeds can be sourced from farther away, if the source location is environmentally similar to the planting location.
Seed zones can be developed in two ways:
- Empirical seed zones are developed for a particular species based on research with genetic data. If it is well understood how genetic variation is distributed among populations of a plant species, then seed zones can be created in detail. These can be used and followed with a high degree of confidence, but they only exist for relatively few species.
- Generalized provisional seed zones are developed when genetic data is not available, and consider major factors including geographic distance and environmental conditions such as topography, elevation, temperature, moisture, and light. They can be applied to any species; however, it is always best to apply as much knowledge as possible about a species’ biology when making decisions based on provisional seed zones. They are excellent to use as general guidelines, or as a place to start in making your seed-sourcing decisions, but they are not definitive rules. It may be possible that a good seed source for your particular species lies in an adjacent seed zone with an environmentally similar area. There may be botanical gardens, universities, or other restoration projects in your country or region where people have experience with your species. The Seed Conservation Directory of Expertise is another place to search for experts in your region. We recommend consulting with other experts if you can, and then making your best judgment based on experience.