By Brad Hanson
Did you know some weed seeds can lie dormant in the soil for more than a century and then sprout when conditions are right? A new factsheet available for free download from the Weed Science Society of America (WSSA) dives into the topic of weed seed longevity, as well as how weed seeds travel, when and why they germinate, and ways they can be eliminated.
“Understanding weed seeds and their lifespan is critical for both farmers and backyard gardeners alike,” says WSSA member Greta Gramig, Ph.D., associate professor of weed science at North Dakota State University. “Seeds can remain viable in the soil for extended periods of time. That means if even a single weed is allowed to go to seed, you may be battling the aftermath for years to come.”
Here are just a few of the many facts about weed seeds that are covered in the new WSSA fact sheet:
- Moth mullein seeds buried by a researcher in 1879 were still able to germinate more than 130 years later.
- Weed seeds can easily be spread and transported far from their original location. Some have found their way into the earth's planetary boundary.
- Earthworms are known to collect weed seeds and move them into their burrows.
- Weed seeds that remain dormant in the soil will often germinate in response to changes in temperature, moisture, oxygen or light.
- Carabid beetles are voracious eaters and can consume large quantities of weed seeds that drop to the soil.