FARGO — As the old saying goes, the road to weedy hell is paved with good intentions.
Most of us begin every summer with the firm intention that this is the year we’ll be in control of our yard and garden. We’ll conquer all weeds when tiny and easy, and our yard will look just like the gardening magazines.
Reality is usually a bit different. The tiny weed that wasn’t worth stooping down to pull last week is now tall with a full-blown seedhead that’s spewing fresh weed seed all over the yard and garden. Or when the end of the season approaches, and it appears weeds have won, it’s tempting to yield victory while telling them, “Just you wait until next year.”
Have you ever wished you could garden without weeds? If you set your mind to it, you can gradually reduce weeding year by year. The concept is straightforward: If a single weed is allowed to go to seed, the impact can be felt for years. If you combine the massive quantity of seeds produced with seeds’ ability to remain viable in the soil for decades, a few escaped weeds can keep you busy hoeing for the foreseeable future. A single purslane plant can shed over 2 million seeds, and the seeds can last in the soil for 25 years or more.
Canada thistle produces thousands of fluffy seeds that can drift for miles and persist for over 20 years. Mustard seed can last hundreds of years in the soil. The weed seeds contained in our soil are called a “weed seed bank.” If weeds are allowed to produce seeds that fall to the ground, they become part of the seed bank that fuels future weed growth. Weed seeds can remain dormant, hidden away in the soil, and then sprout in the future when conditions are favorable.
According to the Weed Science Society of America, the bulk of the weed seed bank will be depleted in five years, on average, if no additional weed seeds are allowed in. As they describe, “Diligence is the key: if even one weed goes to seed, it can send you back to square one.”
If we’re careful about weed management, over time we can reduce the number of seeds in the weed seed bank in our yards and gardens, which reduces the number of weeds sprouting each year. Theoretically, it’s possible for the weed seed bank to become empty with no weed seeds left in the soil. Wouldn’t that be nice.
A reduction in weeding, as the seed reservoir in our soil gradually declines, depends on stopping new crops of weed seed from being added, which happens if we let weeds go to seed in our garden, flower beds and landscape.
Intentional prevention of new seed is the goal. What can we do to stop the cycle of weed seed? Even if weeds have gotten ahead of us and are actively growing, we can at least stop their seed production. Quickly remove the flowers or seedheads from existing weeds before they shed their seed. If there are too many weeds to pull or hoe, at least cut off the tops and deal with the plant itself when you can.
Don’t leave the seedheads laying on the ground, as they can continue to spread seeds. Hand-pulling, hoeing, smothering with mulch and judicious spot-spraying with herbicides can break the chain of weed seed production.
Seeds from weeds and trees can still blow in from the surroundings, and preventing seed won’t stop perennial weeds growing from their winter-hardy roots. But preventing weeds from spreading new seed can greatly reduce our labor.
Don Kinzler, a lifelong gardener, is the horticulturist with North Dakota State University Extension for Cass County. Readers can reach him at firstname.lastname@example.org or call 701-241-5707.