Do all seeds need stratification? If you find errors or additions, please let me know. The trick is to keep them moist, but not sopping wet. Larger seeds tend to do well in a bit of moistened peat or sand, placed into a plastic bag. However, if you’re growing orchids in soil that is moist and rich in nitrogen, then the answer would be “yes”. Smaller seeds can be distributed onto moist paper towels. The bag itself is designed to retain moisture, but like all living things, the seeds need to breathe. Still others need a combination of heat, cold, and moisture. It is only those that I now have growing, have grown in the past, or intend to start. You can tell seeds that need a cold period before germinating because they have hard bony coats that are impervious to water. The answer to the question of “do all seeds need stratification” really depends on where the seeds are planted. Soak seeds in cold water. Starting rosemary from seed can also be tricky, as germination rates are most often deficient and it takes a number of months prior to the crops produce any usable leaves. Other seeds need exposure to heat. If you winter sow you can disregard this table (as long as it gets down to the 30’s at night). (L) denotes seeds that require light to germinate. Allow the rosemary to grow inside or in a sheltered area outside, until they are about 3 inches high and sturdy enough to handle. Stratification Requirements for Breaking Dormancy of Tree seed Dormancy Tree shrub seed does not normally germinate and grow until dormancy of the seed is broken. If you’re growing orchids in containers, for example, you probably don’t need stratification. This list is by no means all inclusive! Seed stratification is the process whereby seed dormancy is broken in order to promote this germination. This is known as stratification, or cold treatment. Do not expect germination of all the seeds as rosemary has a much lower germination rate than some other popular herbs such as basil. 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. Seeds that Like Cold Stratification This table is my working list of perennial herbs and shrubs that germinate better with a period of cold stratification. I’ve generated the table below to show how many days are recommended for cold stratification. How long do Liatris seeds need to Stratify? Put seeds in your fridge to mimic winter stratification. Embryo dormancy is usually broken by a period of cold/moist stratification in which enzyme changes take place in the embryo, allowing the embryo to start developing. Now, most of the number of stratification days come from seed companies. Do rosemary seeds need stratification? Just make sure you winter sow by January. Here are a few ways to promote stratification: Sow seeds in the fall so that they must go through a period of dormancy in the winter. How Can You Promote Stratification? A Combination of heat, mild, moisture and the best form of planting medium are essential to effectively develop this herb in the garden or in pots on a windowsill.