In 1849 a professor at Mishigan State University got curious. Farmers kept asking him how long weed seeds remained viable in the soil. Little did he suspect his long acquaintance with forever mullein.
In my own garden weeds are a constant battle. I can pull every one in a given area, come back in a couple of weeks to find weeds covering the same area.
Weed Seed Bank
Whenever a weed succeeds in producing and dropping seeds, they join others hiding in the soil. These wait, sometimes for years, for conditions to be right. Then they germinate.
Desert wildflowers are a good example of this. For years an area of desert may go without rain. No wildflowers grow.
Right after a rain, the desert blooms as seeds hiding in the soil germinate. People come for miles to see the array of flowers covering what is usually bare dirt.
Longevity Experiment
This professor devised an experiment to find out how long weed seeds would survive in the soil. He put damp soil in over twenty glass bottles. Seeds from twenty-three different common weeds were collected and fifty of each were added to this soil. Then he buried them in a container outside.
For several years the professor took out one bottle and germinated the weed seeds. Another professor took over the experiment leaving years between when a bottle would be dug up.
Fewer and fewer kinds of weed seeds germinated. After 142 years, a bottle was dug up. The seeds were coddled in an attempt to germinate them. Only one kind still does, the forever mullein.
Weed Free Hopes
Most of the common weed seeds only survived a few years. If I can keep any new weed seeds from being added to my soil for five years, most of my weeding problems would be over.
One weed would remain, the forever mullein.
