Cold-moist stratification is a natural process that helps many native seeds know when it’s safe to grow. In the wild, these seeds fall to the ground in autumn and spend the winter exposed to cold temperatures and moisture from snow and rain. This chilly, damp period keeps the seed dormant through winter and signals that spring has arrived when conditions warm up.

For gardeners, cold-moist stratification simply means recreating that winter experience on purpose. By giving seeds a set amount of time in cool, moist conditions—outside or in a refrigerator—you help “wake them up” so they germinate more reliably. It’s an easy and effective way to work with nature, especially when growing native plants that are adapted to seasonal cycles.

Our wildflower seeds are labelled to let you know if they require stratification or pre-treatment. Seeds that are labelled "Pre-Treatment Required" as shown below require cold stratification and occasionally another type of pre-treatment that will be specified on the seed packet's growing instructions.

We've put together a simple guide for 4 different methods of cold stratification for native wildflower seed to help you succeed in growing our seeds. You can view them below, and they are included in our digital seed catalogue if you would like to download a copy.

If you want to skip the fuss and start with species that don't require cold stratification, visit this page to shop only "Easy to Grow" wildflower seed products that do not require pre-treatment. These species are great for spring planting.

How to start seeds that are labelled "Easy to Grow":

These seeds can be direct sown outdoors in spring or fall, either on soil surface or at the depth specified on the seed packet. Do not let seedling dry out while it is establishing.

For more detailed information on cold stratification, check out the blog posts below.

We also now sell small portions of vermiculite perfect for stratifying a single pack of seeds in the fridge. After the stratification is complete, simply scatter the seed and vermiculite mixture on top of soil and press down for good soil contact. Keep soil moist until after seed has sprouted.

If you are looking to establish a wildflower meadow over a larger space, check out these resources on site preparation and establishing a native meadow.