Herbicides needed (pre-emergent?)

Weeds. Weeds everywhere. I can completely eliminate them, go into the house to grab a beer, come back out, and it looks like I never did anything.

I’ve decided I may need to go the herbicide route, probably a pre-emergent, since the vast majority of weeds I deal with are annuals (except white clover and wild violet, but those are scattered enough to deal with).

The worse offenders:
Poa annua (Annual Bluegrass)
Microstegium vimineum (Japanese Stiltgrass)
Either pokeweed or smartweed

Prowl H2O is often recommended, but can it be used on alliums?

Here’s what I grow besides fruits:

Cruciferous crops
Sweet Potato
Sweet Corn

I am assuming there won’t be a one-size-fits all solution, and some of my crops won’t tolerate one herbicide but will tolerate another.

I used to spot-treat with Roundup, and that’s still good for some things, but I keep getting minor drift damage if I come even within a few feet of desirable plants sometimes.

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I can’t help you with a pre emergant, but in 25 years of growing garlic, and for about 15 years of that on a commercial level, the best way I found to get weeds out is to plant, then mulch with about 6 inches of grass clippings from the yard. Every time i mowed, i would either capture the clippings in the bagging unit or rake the lawn. Whenever the grass clippings got below 2 inches thick, another layer was added on. Adding the organic material and nutrients back to the garlic helped grow larger heads, and weeds no longer were a problem.
Today i no longer grow commercially, however, I still grow garlic, peppers, tomatoes, and onions using the same method. Lots of grass clippings and no weeding.


I agree with @Kellogg_Hill_Farms. Mulch, mulch, mulch. And patience. If you keep up with mulching and weeding, it gets better every year. Especially if you use no till/low till practices. Whatever weeds do come up through the mulch are much easier to pull, because the soil will be moister and fluffier under the mulch. Another thing to try is the stale seedbed method. Prepare your bed for seeding, water it well, then wait 2 or so weeks. Hoe down all the weeds that came up, and plant in to that. It works best if you can do the hoeing when you have a couple days of dry, sunny weather to really dry up those weed seedlings.

I’d also recommend investing in a high-quality hand hoe and standing hoe if you don’t already have them, and keep them sharp. Hoeing is much easier than pulling, so long as you get the weeds when they’re small.

Pre-emergents can work well, but there’s a very narrow window of opportunity in the spring.


I buy straw mulch, since I don’t bag my clippings.

And every damn year, the straw mulch has as much weed seed in it as I’m trying to cover up with the mulch. It doesn’t seem to matter where I get it, or if it’s “weed free” or not.

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Try shredded leaves from your trees, if you have a lot of raking to do. Makes A+ super premium mulch, with only the odd maple seed in it.


Straw mulch does not have the same amounts of nutrients as grass clippings. Its already lost its moisture, and therefore does not heat up while decomposing. It doesn’t smother weeds out because it doesn’t compact and snuff out light, like a thick layer of grass clippings. Straw is a by-product of grain harvesting and is from a mono-culture. No beneficial symbiosis within communities of organisms like you would see in a green compost like grass clippings. Leaves work as well, just not as well as grass clippings, in my experience.

What do I shred them with?

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Don’t grass clippings mat down too much and cause issues with water permeability?

I’ve never had issues with water permeability, actually just the opposite. I never watered garlic and rarely have to water the tomatoes or peppers. The mulch keeps the moisture locked into the soil, as the sun can not hit the soil to evaporate out the rain water.


Your lawnmower is the easiest if you have a power mower. You may yet find a use for your bag! You can either just pick up what’s on your lawn, or you can rake/blow them into a pile and shred it right there. I use a Toro blower/vac, or you can use a string trimmer in a barrel like a giant immersion blender.

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I can’t too strongly recommend finding the label for the chemicals you want to use. You will answer many questions and assure you won’t damage your crops.
Pre-emergents can be used anytime the soil is clear of weeds and they are applied according to label directions. The label on pesticides is the law, you have to read, understand, and follow it.
There are also post-emergents labeled for grass control and broadleaf control in differing crops, again, you need to read and follow the label directions.
I have grown veg and fruit for 30 years and everytime I reach for the sprayer I also reach for the label. I am reminded every time I spray I do forget what and how to spray.
A big help is the midwest fruit and veg spray guides printed by various universities.


What do you do to your lot after your plants finished? if you leave the lot as is, it gives the weeds ability to grow and seed till frost and also from early spring to the point you start to care of the soil. Try to cover it with cardboard as soon as you plants can be harvested/removed row by row - it will make weed pressure somewhat easier. And if you find the way to mulch all your plants, it will make it even more easier. I use shredded leaves for mulch(I have gas chipper/shredder) - they work great for suppressing weeds and rot over winter without taking much nitrogen from the soil as wood chips would do.

I bought a combination leaf blower/mulcher and it is great to have for making mulch. Less baby maples survive to sprout also. And like someone else said it reduces the number of times you’ll need to water and it enriches the soil!


if you can get green arborist woodchips, they work excellent to keep out weeds. its all mixed with chopped leaves so it will heart up and nothing will grow on green chips for at least a year. i add a new 3in. layer every spring. haven’t weeded in 6 yrs now since doing this.


The other bonus of any mulch is that just covering the soil makes it richer. Even plastic or a wooden board, to a small extent. There’s always Nitrogen being fixed or freed from organic matter by bacteria in the soil, but a lot escapes into the atmosphere in bare soil. Organic mulches break down over time and provide extra organic matter for this process. Leaves in particular are a great source of fertility. Many people use composted/aged leaves as their only source of fertilizer. I’ve been putting shredded leaves and nothing else around some sorry-looking hostas that were here when I moved in. A year later, they’re already looking twice as good.


we have mostly conifers up here so not much leaves. i do collect some from the universities compost piles to add too mine but don’t get a lot. wood chips from the firewood business or arborists is plentiful though.