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njbiology

How to kill annual grasses; not native wildflowers? Herbicide?

njbiology
9 years ago

Hi,

Please SKIM TO THE BOTTOM, if you're short on time. i think that this could be a useful topic thread for a lot of people in my situation; a common one.

This spring, I completely tilled my soil and sowed a great number and quantity of native wildflower species (perennial, some annuals, some spring emphemerals included) and native grass/sedge species (perennial). The area totals 1/8 acre; graded from upland to lowland, and full sun to deep shade -- seeds sown accorded to appropriate area of property.

I wound up with a blend of 1/3 wildflowers, 1/3 native grasses/sedges, and 1/3 EXOTIC ANNUAL GRASSES: mostly barnyard grass and crabgrass. I wasn't, at the time, knowledgeable enough not to (1) know not to deeply till up the ground, thereby exposing latent weeds in the seed bank/soil and (2) know that those quick growing grasses were barnyard grass and crabgrass -- not quick growing native grasses, as I initially thought was the case.

I'm finding it too difficult to hand-weed the entire 1/8 of an acre. I did half of this, because that half featured a loose soil (broken-down woodchips); the other half is mesic clay, so the grasses are well-anchored and much more developed. When I pull them out, out comes a good number of native seedlings, and I may be exposing more weed seeds. I also have exotic flowering weeds like smartweed, etc. but these are easier to hand weed.

1. Is there an herbicide that I could spray that will only kill grasses; never any wildflowers -- even if the plant is grass-like, such American Acorus, blue-eyed grass, native iris species, etc.); perennial/annual; most Spring ephemerals included.

2. Is there an herbicide that will not only be save for the above wildflowers, but do less harm than others to native grasses/sedges? If so, I can spray the area that have flowers/native grasses/exotic grasses, and just deal with the fact that some percentage of the native grasses will be gone from those spots.

3. Should I just mow the whole thing low? Wont the crabgrass and barnyard grass just seed low after I do that?

4. Can I soak herbicide into a bath towel and drag this over the tall grasses, which will serve as an umbella to the native grasses and flowers many inches bellow; avoid over-saturating the towel.. so there will be less dripping. Will this be sufficient to cover the weeds? I think this would work in area where the exotics are tall. For the areas where exotics and natives are short, ill wait until the exotics get really tall, as they usually do exceed the height of the natives for the first year of growth. I think the weeds mostly harm the natives, the first year, because they rob them of sunlight.. not because they share nutrient and water resources.

Any ideas?

Thanks!
Steve

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