Cold-Stratified Milkweed Seeds — Ready to Sow

Easily plant milkweed with stratified seeds! This new product is an improved replacement for our seed bombs, which were a great success.

To be planted in spring, milkweed, like most northern native plants, must undergo a cold treatment of at least 15 days under specific conditions (temperature, humidity, etc.). Good news, we've already done this work for you! Our packets of stratified milkweed seeds arrive already cold-stratified!

This treatment replicates the winter conditions that seeds naturally experience and helps deactivate the chemical and physical barriers that delay germination. These protections are a natural adaptation of milkweed and other northern plant seeds, preventing them from germinating prematurely during an autumn or winter warm spell that could be followed by a frost. Without cold stratification, germination rates can be very low (3–4%) or even zero for older seeds. The clay and potting soil coating of our seed bombs will allow the seeds to germinate without being eaten by birds or rodents.

Each packet contains a quantity of seeds varying by the chosen variety, along with a substrate (sand) that has been pre-stratified in cold conditions for 30 days.

Seeds must be sown upon receipt of the package in order to preserve their germination potential.

Help monarch butterflies and pollinators by planting native milkweed. Milkweed leaves are the sole food source for monarch butterfly caterpillars, while its flowers nourish several endangered pollinator species with their abundant nectar.


• 1 bomb = 1 3/4" x 4" stick, divisible in 4 cells each containing seeds. You can cover up to 4 square feet per seed bomb.
• About 8 to 12 stratified seeds per stick.