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Cold Stratification

Cold stratification mimics winter conditions to break seed dormancy and encourage germination. This process is essential for many native and wildflower species, ensuring that your seeds sprout at the right time for optimal growth. See the instructions below or watch the video to learn how!

Instructions

Prepare a Moist Medium:

Use a damp material such as sphagnum moss, sand, or paper towels.
Ensure it’s moist (not soaking) to prevent mold growth.

Combine Seeds with the Medium:

Place your seeds in a sealable plastic bag or container.
Mix them gently with the damp medium.

Seal and Refrigerate:

Seal the bag or container, squeezing out excess air.
Place it in your refrigerator (avoid the freezer).
Maintain a temperature between 34–41°F (1–5°C).

Stratification Period:

Leave the seeds in the refrigerator for the recommended time (typically 4–12 weeks, depending on the species).
Check occasionally to ensure the medium remains moist and there are no signs of mold.

Return to Planting:

After the stratification period, remove the seeds from the refrigerator.
Plant them as directed on your seed packet, and expect germination as conditions warm.

Tips

Follow Specific Guidelines: Different species have varying stratification needs. Always refer to your seed packet or trusted gardening resources for precise timing.
Monitor Moisture: Keeping the medium damp (but not wet) is key to preventing mold while still allowing the seeds to experience cold conditions.
Label Your Containers: If stratifying multiple seed varieties, label each with the seed type and start date for easy tracking.
Combat Mold: If you notice early signs of mold, prepare a dilute hydrogen peroxide solution by mixing 1 teaspoon of 3% hydrogen peroxide with 1 cup of water. Lightly spray this mixture onto the medium to help inhibit mold growth without disturbing your seeds.

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