Germination Codes

Your seed packets are marked with a germination code that indicates sowing instructions for the species.

  • A Seeds — Seeds marked with germination code A are among the easiest to sow, and this code indicates their temperature requirements. They do not need a winter cold period to germinate. Sow outdoors in fall or early spring.
  • B Seeds — Seeds marked with germination code B are among the easiest to sow, and this code indicates their temperature requirements. They do need a winter or cold period to germinate. Sow outdoors in fall or winter. 
  • C Seeds — Seeds marked with germination code C need light to germinate. Sow them on top of the soil’s surface, and leave uncovered. This germination code will appear in addition to other codes that relate to temperature requirements.
  • D Seeds — Seeds marked with germination code D need an alternating warm-cold-warm cycle to germinate. We recommend that you sow them outdoors in spring or summer (warm period). They’ll germinate the following year, after a winter (cold period) and then spring (warm period).
  • E Seeds — These seeds will not germinate if they dry out. Sow them immediately.
  • F Seeds These seeds may take two years to germinate. Sow outside in fall or winter and look for germination in the second spring. A shady location prevents the flats from drying rapidly and reduces the need to weed.
  • G Seeds — These are large seeds that should be soaked overnight in water before sowing.
  • FERN Spores — These are challenging to sow. Sow spores in a warm, bright location in a sealed container, and keep them moist. Directions will be enclosed with your package.

Choosing Seeds to Sow

We advise beginner native seed sowers to start with seeds marked with germination codes A (sow in spring or fall) and B (sow in fall or winter).

Seeds with germination codes C, D, E, F, and G, as well as Fern spores can be tricky and take patience; they’re for more experienced native seed sowers.

If you have questions about seeds and germination guidelines please contact us at info@wildseedproject.net.

All seeds can be sown and placed outdoors in fall or winter bypassing the need for an artificial indoor cold stratification (refrigerator) required for some species when planted in spring. This is the simplest method. See How to Grow Natives From Seed for detailed instructions.