Think it's an overstatement to call it the war against weeds? Here's what you're up against. A single redroot pigweed is able to produce up to 30,000 seeds in a season. And those seeds can remain alive in the soil for 70 years waiting to sprout and overrun your perennial border at any time. Controlling weeds is a fight you can't win entirely because they always grow back. But you can keep weeds under control by depriving new ones of the conditions they need to take root in the first place and then removing those that sprout.