Favorite brand pre-emergent?

[DocD357]

Originally Posted by kinkytoes

*Sobs* Why do people post questions about using chemicals in the gardening forum.

Because they work?

[TinaMcG]

Originally Posted by alsidw

I have tried the Walmart generic Roundup and it is very slow to work.

I usually see results in a week, and that is a good thing. That means the chemical has been transported to the roots and is giving you a thorough kill.

[TinaMcG]

Originally Posted by DocD357

Because they work?

Why shouldn't people ask about garden chemicals in a garden forum? Even in an organic garden forum there would be questions about pest and weed control. Integrated Pest Management is widely accepted as the most sensible approach to pest control, and I have absolutely no problem pulling out the big guns when necessary.

People come here wanting to know what to use, and when to use it. It is better that they do ask questions rather than just dump a bunch of chemicals all over in the hopes that they'll work. If you choose not to use any pest control chemicals in your garden, that is fine, but please don't preach to those of us who have some education on the subject and use them discreetly and responsibly.

[DocD357]

Originally Posted by MrWillys

Is one brand of pre-emergent better than another? Also, do most of you buy concentrate and spray it in a bug sprayer?

Sorry, got off topic without answering! There's good advice here. It depends on what sort of area you need to treat in terms of the concentrate vs Ready-to-Use (RTU). Little 1-2 gallon sprayers are great for a number of products, but cleaning between uses is important, i.e. clean out as soon as you're done spraying. If I were you, I'd have one sprayer for non-selective or heavy-duty products that you know will injure or kill whatever or a lot of you touch (like glyphosate, glufosinate, pramitol, Tordon/picloram, triclopyr), one for selectives or pre-emergents (Preen, or 2,4-D), and probably one for insecticides/fungicides if needed for your application.

Some of the common PRE herbicides contain trifluralin, pendemethalin, oryzalin, dithiopyr, and some others.

Preen has trifluralin in it, and it's the one that I advise users to water in as UV light will speed the breakdown (considerably). Some folks are familiar with the yellow-colored granules from professional landscapers and lawn companies, that's the active ingredient pendamethalin. Dithiopyr isn't too widespread on the market (Dimension). Oryzalin is Surflan, as Bulldogdad noted, also good stuff.

Timing is sorta important on these things, as they are going to have virtually no effect on emerged weed species. Going too early means that the product degrades (or worse, runs off into the ditch) and may not have the concentration necessary to blast the root meristems of the weeds to oblivion (insert evil weed-killing laugh here... okay, it really doesn't BLAST them).

Great advice below, too.

Originally Posted by Bulldogdad

FOLLOW THE INSTRUCTIONS TO THE LETTER for preemergent to work correctly and not get pollute run off.

If you don't understand something on the label, don't feel bad or embarassed about it. Labels are designed (and EPA reviewed) to get you results and minimize off-site effects (if any). Ask your local Extension Agent, most counties have one or are near one. Better yet, ask your Extension people if there is a Master Gardener to talk with. They love to talk about gardening and would be thrilled to help. If that fails, post your question here, if that fails, feel free to send me a note.