You bought those beautiful native seed packets with the best intentions, dreaming of vibrant blooms and buzzing bees. But life got busy, and now they’re still sitting on your shelf. Don’t worry, you’re not alone! A common question we get is, “Is it too late (or too early) to plant my seeds?” The answer isn’t always straightforward, and it often comes down to one crucial process: stratification.

Nature has ingenious ways of ensuring the survival of its plant species. Many native seeds possess various mechanisms to prevent premature germination.   They are hedging their bets, so to speak. These mechanisms, collectively known as seed dormancy, can involve hard seed coats, chemical inhibitors, or an internal requirement for specific environmental cues. While we can offer general guidelines and recommendations for stratification, remember that each seed has its own quirks, and germination can sometimes involve a bit of trial and error. But that’s part of the joy of growing native plants – discovering the unique needs of each species and witnessing their resilience.

What is Stratification?

Stratification is essentially mimicking nature’s winter for your seeds. Many native plants have evolved to require a period of cold and moisture before they’ll germinate. This prevents them from sprouting during a late-season warm spell, only to be killed by frost.

Do My Seeds Need Stratification?

Here’s a breakdown of the seeds we offer:

Seeds Requiring Stratification

Seeds Not Requiring Stratification

What if I Missed the Ideal Planting Window?

Don’t panic! Here’s how to proceed:

Seeds That Need Stratification:

If you’re still within the recommended timeframe:

If you still have the number of required days of cold temperatures yet to come, plant them directly outside into cold soil.  For example, Sneezeweed only needs 30 days of stratification, so could reasonably be planted outside in late March before the soil warms.

If you’re outside the recommended timeframe: 

You have three options:

• You can still stratify your seeds in the refrigerator. Mix them with slightly moistened sand or peat moss in a sealed bag or container and store them at around 35-40°F (2-4°C) for the specified number of days.  Then plant them outside.
• You can try direct sowing outside. While germination rates might be lower, it’s worth a shot. Plant as soon as you are able, and see what happens.  Some may not germinate until next spring!
• Consider Fall Planting: For most native species, fall planting is ideal. The natural winter conditions will provide the necessary stratification.

Seeds That Don’t Need Stratification:

These can generally be planted whenever the soil is workable. Most native seeds germinate best in cool temperatures, so don’t wait until the soil gets too warm.

Fall Planting Benefits: Even though these seeds don’t require stratification, fall planting can still be beneficial. It allows them to naturally synchronize with their preferred germination timing in the spring.

Tips for Successful Stratification:

Moisture is Key: Keep the stratification medium consistently moist, but not soggy.
Label Everything: Clearly label your containers with the seed type and stratification start date.
Don’t Give Up: Even if germination is slow, be patient. Some seeds can take their time.

Remember:

Always check the instructions on your seed packet.
Natural stratification (fall planting) is often the easiest and most effective method for all seeds.
Don’t let those seeds go to waste! With a little understanding of stratification, you can still enjoy a beautiful garden, even if you’re a bit behind schedule.

We’re here to help!

If you have any questions about seed stratification or planting, please don’t hesitate to contact us.