Forest land: Site Prep Chemicals

Asked February 6, 2020, 11:26 AM EST

We recently acquired about 4 acres of old pasture-land that we'd like to convert into forest. It's now covered with waist-high blackberries over about 70% of the area, with heavy grass over all the rest. We're planning to backpack spray it after leaf-out (early summer) and then mow/flail it down, then plant next winter. I'm not sure what chemicals are still approved for use on forest land anymore. In the old days, I'd probably use a combination of Roundup and Garlon 3 at a 2% level. What would you recommend these days? Thanks for your advice! -- Dave Johnson (an old forester)

Washington County Oregon

2 Responses

While there are a variety of newer herbicides that could work, your basic prescription from the "old days" should work well for blackberries and grass. For best results on blackberry, applications later in the season after it has fully leafed out should be more effective than early summer. A late summer site preparation treatment is commonly used.

Also, you might take inventory of any other problem weeds besides grass and blackberry to see if there is something requiring special treatment. Of course you must follow the label and use products registered for forestry site preparation. For a refresher on weed control in forestry applications, see https://pnwhandbooks.org/weed/forestry-hybrid-cottonwoods/forestry

Thanks, Glenn. Good point about the leaves being fully developed for chemical uptake. We'll be sure to wait for that, probably late summer, as you suggest. Thanks for that link to the chemical refresher for forest land too. I'll check it out. I'll be sure to follow the label instructions and also file a Notification with ODF before we do any spraying. Take care... -- Dave Johnson