Detention Basin - Bioswale

If you are seeding a prairie seed mix in the fall, pre-treatment (stratification) is not needed, as the seeds will be exposed to cold, damp conditions in the soil over winter.   1. Prairie grass seeds do not require moist stratification (cool moist pre-treatment). Only dry stratification (cool dry pre-treatment) is needed to improve the germination of prairie grasses. The grass seeds that you receive from us have been dry statified (stored in cool dry storage).
2. Most prairie flowers (forbs) will benefit from moist stratification. Some species will exhibit little-to-no germination without mosit stratification, while others will germinate at lower percentages. Many forbs germinate well with only dry stratification (Purple Coneflower, Yellow Coneflower, Purple Prairie Clover, Lanceleaf Coreopsis, Bergamot, Black Eyed Susan, and Brown Eyed Susan). However, moist stratification can be applied to all prairie seeds, whether or not they require it.
3. As a rule of thumb, if you are seeding a prairie in the spring, it is best to moist stratify the forbs for at least 30 days, for the best germination.

Our native seeds are Dry Stratified, which means that they are stored in cold temperatures over winter, without the presence of moisture. This process helps increase germination rates in most prairie grasses, and for some of the wildflowers.   None of our seed is Moist Stratified prior to being shipped – a process in which the seed is mixed with a larger volume of dampened inert material such as fresh clean sawdust, builder’s sand, or similar substance, and placed in a refrigerator inside a Ziploc bag. Most prairie flowers and native sedges and rushes will show significant increases in germination after 30 days of moist, cold treatment. Some genera, such as Baptisia, Iris, and the grass genus Spartina, require 90 days or longer to show improvements in germination.   Seed mixes sold in quantities of ten pounds or more are packaged individually by each species. If the quantity sold is less than ten pounds, we pack the seed in three separate bags: wildflowers, “fluffy” grasses, and hard round grasses such as Prairie Dropseed and Switchgrass.   If you plan to broadcast your seed mix in the fall, all seed species will acheive moist stratification naturally, over the winter. You will not need to pretreat the seed for a fall seeding.   If you plan to broadcast a seed mix in the spring, the seed (germination rates) will benefit from being moist stratified prior to seeding. If combined, the different wildflower species in your seed mix package can be moist stratified together. The median number of days to moist stratify should be sufficient.