Seeds Of Dried Flowers
hibiscus seed
(Image credit: Morana Franov)

When it comes to seed germination, many people don't realize that some seeds require cold treatment in order for them to sprout properly. Continue reading to learn more about this cold treatment for seeds and which seeds require cold treatment or stratification.

What is Stratification?

In nature, seeds require certain conditions in order to germinate. Seed stratification is the process whereby seed dormancy is broken in order to promote this germination. In order for the stratification of seeds to be successful, it is necessary to mimic the exact conditions that they require when breaking dormancy in nature. 

Some seeds require a warm and moist treatment, while others require a cool and wet treatment. Even still, other seeds require a combination of both warm and cool treatments followed by a warm treatment, or a combination of warm and cool moist followed by a dry cycle and warm period to germinate. 

Therefore, knowing what seeds require to break dormancy is critical before beginning any seed stratification project.

Is Cold Stratification of Seeds Necessary?

So, when is cold stratification of seeds necessary? Cold treatment for seeds is necessary for plants or trees that require time in the ground over winter in order to germinate. 

If you are starting cold treatment in the late summer or fall, you can put the seeds in a pot of soil and dig the pot into the ground. The seeds will sprout in the spring. However, if you are starting treatment in the early season, you will want to soak seeds for 12 to 24 hours and put them in a plastic bag or sealable container with equal amounts of sand and peat. 

Seal the bag or container and place it in the refrigerator for 10 days. Label the container or bag so that you know which seeds they are. Check the seeds regularly to be sure that the planting medium is moist. 

Check the seeds after 10 days to see if they are sprouting, as some seeds may require a longer period of cold and wet conditions. (Some seeds even require time in the freezer to break dormancy.)

What Seeds Require Cold Treatment?

Many plants require cold seed stratification in order to break the dormancy cycle and germinate. The following are some common plants requiring a cold treatment for seeds (Note: This is not an all-inclusive list. Be sure to research the germination needs of your particular plants beforehand):