Why so many weeds?
Gardeners often ask why they have so many weeds. The answer is quite simple, we plant them!
Weed seeds can blow in, wash in with surface water, or be introduced with the application of soils and organic matter, like manure. Birds and other wildlife also distribute weed seeds. However, the majority of weeds come from seed unsuspectingly planted by the gardener. In other words, weeds we allow to go to seed.
For example, a common pigweed plant, with its long reddish taproot, produces one hundred and seventeen thousand seeds per plant. That means just nine pigweed plants allowed to go to seed disseminate over one million seeds! And these seeds are viable for forty years. Purslane, with its pinkish, fleshy stems and leaves, produces fifty-two thousand seeds per plant. Purslane seeds are viable for twenty-five years. And how about the common dandelion? It typically produces only fifteen thousand seeds per plant.
So don't let weeds go to seed. A gardener who doesn't let weeds go to seed will have significantly fewer weeds each year.
Each time the garden is cultivated or tilled, a new crop of weed seeds are brought to the surface and are ready to germinate. To suppress weed germination, avoid unnecessary tilling. Application of a surface mulch also helps suppress weed seed germination.
For more information, see the following Colorado State University Extension fact sheet(s).
For more information, see the following Planttalk Colorado™ script(s).
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Updated Tuesday, November 19, 2013