how to stratify native seeds
Many native seeds need a cold, moist period before they will germinate. This is called moist stratification, and can range from 10 to 90 days or more, depending on the species. Follow these simple tips to get your seeds ready for germination!
Place your seeds in a Ziploc bag labelled with the species and date. Each species will have a different requirement, so I like to put the stratification period on the bag next to the date (i.e. March 4th, 30 days). You can look this information up online, or if you ordered seeds it will often tell you on the packet.
Add a small scoop of sand or vermiculite - sand for really small seeds, vermiculite for larger ones. This will hold moisture around your seeds without sitting in water. Paper towels can work in a pinch but they tend to get moldy, which can damage your seeds. My preference is vermiculite because you can be pretty confident that a bag of vermiculite from the store isn’t harboring too many mold spores. Then after the cold treatment, it acts as a filler to evenly spread your seeds for germination.
Spritz with water until moist but not soggy, and place in the refrigerator.
That’s it! I like to check on my seeds every couple weeks to make sure they are still moist and haven’t started sprouting in the bag. If they’ve sprouted, it’s time to take them out and put them in dirt!