Marestail . . . if you frequent farm stores you've heard people talking about how hard it is to kill. If you've been to a lawn and garden store, it's the one they call, "that bushy leafed weed that Roundup doesn't kill." Yes, that's correct, Roundup doesn't kill it and it's seemingly everywhere again this year.
Marestail has been plaguing farm fields and landscapes for the past 5+ years. It can germinate all year long, survive the winter, and then grow aggresively in the spring. If not pulled out or destroyed otherwise, the marestail plants that overwinter will make seed heads in late summer. Because the seed is similar in apprearance to dandilion seed but only half as large, marestail seed (or fuzz as some call it) can be carried in the wind for miles. That, in fact, is the reason it can be found most anywhere - from city landscape to farm fields; growing in gravel driveways and even within cracks in pavement - regardless if it's ever been there before.
It has developed nearly total tolerance to Roundup. Only broadleaf herbicides have proven to be effective and they must be applied before the plants are 4 to 6 inches tall. Broadleaf killers found to be effective such as 2,4-D and dicamba are the same as those used to control dandilion or clover in lawns. Once plants exceed 6 inches in height, pulling the plants while being carefull to also get as much of the root as possible is about the only effective method of control.
DON'T waste money, time and effort spraying marestail with Roundup (some claim it only makes it mad!), and DON'T let it go to seed!
- Stan Smith, PA, OSU Extension, Fairfield County