Types of Seed Stratification

These techniques simulate the natural process that occurs when seeds fall to the ground in autumn, go through a winter period, and then germinate in spring. 

The exact process you choose (there are two options) depends on the flower variety you’re growing. Let us explain! The different processes are defined below. 

Cold Stratification  

Cold stratification involves exposing seeds to a period of cold temperatures without any moisture. The cold temperature breaks down the seed coat and allows water to enter the seed, which will then germinate when planted.

How to perform cold stratification:

1. Mix the seeds with some damp sand or peat moss to help prevent them from drying out. 
2. Place the seeds in a sealable plastic bag or container. 
3. Put the container in a refrigerator where the temperature is between 33 to 41°F. 
4. Keep the seeds in the fridge for the recommended amount of time, which can vary depending on the species of plant. A typical range is 4 to 12 weeks. 
5. After the recommended period, remove the seeds from the fridge and plant them. 

Cold Moist Stratification 

Cold moist stratification is a similar process to cold stratification but with the addition of moisture. This technique is often used for seeds that require higher moisture levels to break dormancy.

How to perform cold moist stratification: 

1. Mix the seeds with some moist sand, peat moss, or vermiculite to help maintain moisture levels. 
2. Place the seeds in a sealable plastic bag or container. 
3. Put the container in a refrigerator where the temperature is between 33 to 41°F. 
4. Check the moisture levels of the mix periodically and add more water as necessary. 
5. Keep the seeds in the fridge for the recommended amount of time, which can vary depending on the species of plant. A typical range is 4 to 12 weeks. 
6. After the recommended period, remove the seeds from the fridge, plant them and keep the soil consistently moist until the seeds germinate. 

Not all plant seeds require cold stratification or cold moist stratification to germinate. Before you embark on the process, research the specific species of plant you’re growing to determine whether or not it requires stratification.

Shop here for seeds that require stratification.