The plants you call "weeds" are true survivors, thriving against all odds.
Most propagate by seed and the worst offenders can produce tens of thousands of seeds per plant, per season. Common lambsquarters , for instance, easily produces up to 70,000 seeds annually per plant, seeds that can last decades if left undisturbed below the soil surface.
Not all seeds sprout into weeds immediately, of course. Millions of them settle into the soil where they can wait years for a bit of sunlight to spark them into growth. Particularly pernicious are broadleaf perennial weeds, such as knotweed, purslane and thistle that propagate by seed and also vegetatively, regrowing from bits of the plant or root. If you chop up these types of weeds, you merely make more of them.
It is possible to win the war on weeds. Prevention hinges on:
• Stopping current weeds from going to seed.
• Preventing future weed seeds from sprouting.
First, remove any existing weeds, including roots. Starting with this clean slate, add a layer of protective mulch to starve any just sprouted weeds of sunlight.
Next, apply a pre-emergent weed preventer such as Preen to prevent any existing weed seeds in the top layer of soil or mulch from forming roots.
Periodically, a few weeds will still crop up – remove them. Re-apply weed preventer mid-season to keep seeds from the current year’s crop from germinating, bearing in mind that many weeds set seed in late summer or fall. Refresh mulch as needed.
Each spring, as you start the process again, you’ll find fewer and fewer weeds to deal with. Do a weekly weed patrol, enjoying your garden while you pluck any offenders. Following a simple seed-focused routine allows you to literally turn the corner on weeds.