Cold Stratification

stevebradford

Moderator
Staff member
Cold stratification for temperate carnivorous plants Is to simulate the period of cool, damp conditions that happen during winter. Stratification helps to break down or allow moisture to penetrate the seeds waxy protective layer. Cold stratification involves placing seeds in a refrigerator or outdoors at a temperature below 5 degrees C on a damp surface for 2-6 weeks. Longer durations of cold temperatures will encourage the most germination, but mold growth can spoil the seed. When you take the seeds out of stratification it simulates the start of spring.

Option 1: Sowing seeds directly on your growing soil mix. Prepare the desired soil mix that you would use to grow your seed. I prefer to use previously used soil as its less likely to mold than fresh. Lightly moisten the soil mixture so that its consistently moist but not soaking Sprinkle seeds on surface, cover or place the pot in a plastic Ziploc bag. Leave in the refridgerator for your preferred duration of cold stratification.
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Option 2: Moist towel method. Place your seeds in the centre of the paper towel or a blue shop towel that won’t go mushy or fall apart. Clump the seed in the centre of the towel and place the folded towel inside a Ziploc bag, moisten with water or 3% hydrogen peroxide. Leave in fridge for the desired period of cold stratification.
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Option 3: Submerge or float seeds. Using a small container, science glassware is ideal. Partially fill with a small amount of water or 3% hydrogen peroxide, keep the seeds submerged or floating for the entire stratification period. Once they have stratified for an appropriate time suck up the seeds into a pipette, eyedropper or gently rinse the container on to your planting media taking care not to wash the seeds away or bury them.
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Be careful to monitor for mold. In any of the above methods mold can develop and ruin your seeds. To help prevent that don’t include debris, bits of the flower or stalk, check on your stratifying seed periodically.

Remember to label your stratifying seed with the type and date, it’s easy to forget what’s what after a month.
 
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