Isolation Techniques for Seed Saving

ISOLATION TECHNIQUESSeed Savers Exchange

Grant Olson

Our mission is to save North America’s diverse, but endangered, garden heritage for future generations by building a network of people committed to collecting, conserving, and sharing heirloom seeds and plants, while educating people about the value of genetic and cultural diversity.

Seed saving is the process of saving seeds from open-pollinated fruits, vegetables, grains, flowers & herbs.

Open-pollinated varieties are maintained by allowing pollen to flow only between plantsof the same variety.

When pollen flows between different varieties within the same species, this is known as cross-pollination.

Cross-pollinated seed is not ideal for seed saving.

Some form of isolation may be necessary to prevent cross-pollination between plants of different varieties within the same species.

Depending on your plants and your environment, isolation may not be required.

(flower structure)

anther produces pollen

seeds form in ovaryafter fertilization

stigmareceives pollen

grow only one variety

distance

Self-Pollinating, Perfect Flowers



Insect-Pollinated, Perfect Flowers



Insect-Pollinated, Imperfect Flowers

Insect-Pollinated, Monoecious Plants




Wind-Pollinated, Monoecious Plants

Wind-Pollinated, Dioecious Plants

Insect-Pollinated, Self-Incompatible Plants

Wind-Pollinated, Self-Incompatible Plants

time

Is physical isolation required?

• are different varieties of your crop/species being grown within the pollination zone?

• are these different varieties flowering at the same time as your plants?

barriers for self-pollinating plants

barriers for self-pollinating plants

barriers for insect-pollinated plants



barriers for wind-pollinated plants

for more information:

Seed to Seed, Suzanne Ashworth

The Organic Seed Grower,John Navazio

A Seed Saving Guide for Gardeners and Farmers, OSAwww.seedalliance.org/publications

SSE Webinarswww.seedsavers.org/webinars

Education

Isolation Techniques for Seed Saving