# Pre Emergent for Dandelions



## arrigetch peaks (Mar 27, 2019)

Please bear with me, I'm new here. I have a couple of neighbors the like the natural look. They are retired. Back where I was born, retired people tended to their lawn and gardens. Where I live now, retired people seem to go do things that require them to be away from the house (kayaking, hiking). It is hard to fault them, considering, I live in the best state in the world. If there is a world champion dandelion grower it is my neighbor. He grows 2 1/2' tall dandelions with massive blooms. The problem I have is his "glorious" patch of dandelions is trying to spread to my lawn. After that ranting, I have one question. Is there a Pre Emergent for dandelions?


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## chrismar (May 25, 2017)

Neither dimension or prodiamine are labeled to prevent dandelions, however dandelions are some of the easiest weeds to kill. Mine almost seem to crumble if I give them that "dad look", but if they don't a quick shot of 2,4-D will take them out easy peasy. Other than that, good cultural practices are the best combat as it makes it quite difficult for the seeds to germinate and establish.


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## Green (Dec 24, 2017)

If you truly need a pre-M for Dandelions, might want to look into Gallery. But it does nothing for Crabgrass.


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## HoosierLawnGnome (Sep 28, 2017)

I have had the same situation in times past, and prodiamine has always served me well. Sometimes it looked like it was snowing in July.


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## g-man (Jun 15, 2017)

I'm with HLG. I use prodiamine and I don't see dandelions in my yard. It is a winter annual, so what you are seeing now, started last fall.


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## LawnCreepsLtd (Sep 8, 2018)

Dandelions are Perennial broadleaf weeds, therefore they will come back year after year and reproduce by a deep taproot AND seed. So while a pre emergent will help it will not prevent all of them in one or several years They are very easy to kill via common herbicide and like many weeds the best time to eradicate them is in fall when they are storing nutrients for the winter. Obviously you don't want to wait that long so again, any 2-4D product will shrivel them up. so yeah...a pre-emergent to stymie, then hit them with a post emergent when they arrive, and then continue to monitor and walk your yard with a fine tooth comb in Early fall to hit them as they store nutrients for winter. After a season or 2 and with good cultural practices, your lush lawn will out compete and ward off your neighbors buddies, and as time rolls on you can hopefully reduce the amount of herbicides you're putting down into that earth.....


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## Dkrem (Mar 16, 2019)

+1 to everything said so far. I'd also like to add that when I am spraying weeds I tend to somehow get distracted when making my turns and sometimes accidentally get a little juice a few feet into my neighbors yard. One time I saw a bird and before you know it I had accidentally sprayed halfway into his front yard of dandelions that is upwind of my yard.


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## All Day NPK (Feb 17, 2019)

I believe dandelions are a result of low calcium and in many cases compacted soil. The deep tap root goes down deep into the soil to get calcium where the grass roots cannot. So to avoid dandelions make sure your calcium is in range (via soil test) and you're not compacted. Core aeration could help but to get really deep, a liquid aeration product like Air-8 can really help there.


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## osuturfman (Aug 12, 2017)

Check out Defendor for Corteva/Dow.

https://www.domyown.com/defendor-herbicide-p-15625.html

It's lights out on dandelions as a Pre. It can be tank mixed with typical Pre-M and applied at the same time. The use rate is very low at 4 fl oz/A and they don't sell it in smaller packages, so you may want to find someone to split it with.


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## Dkrem (Mar 16, 2019)

All Day NPK said:


> I believe dandelions are a result of low calcium and in many cases compacted soil. The deep tap root goes down deep into the soil to get calcium where the grass roots cannot. So to avoid dandelions make sure your calcium is in range (via soil test) and you're not compacted. Core aeration could help but to get really deep, a liquid aeration product like Air-8 can really help there.


My last soil test had calcium at 12,000 (yes that's right). My dirt grows dandelions just fine if I let it.


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## g-man (Jun 15, 2017)

@All Day NPK I believe dandelions are the result of the thousand of seeds that the drop and grow from, regardless of calcium.


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## All Day NPK (Feb 17, 2019)

Touché!

Dandelions are a result of seeds. Yes. But they favor growing in certain conditions:

High Concentration May Indicate: Very low calcium, low phosphorus and iron, high potassium; Low overall fertility; Low mowing height; Compaction

Corrections: Add gypsum/calcium lime; Increase nitrogen, phosphorus; Avoid potassium, magnesium; Aerate soil; Mulch / top dress to increase organic matter; Mow high and frequently; Leave lawn clippings; Top seed grass to increase competition

Source: https://ucanr.edu/sites/AdvIPM2016June/files/243847.pdf


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## g-man (Jun 15, 2017)

I know this is something John Perry started to preach in his youtube videos. He pointed to similar references. I researched for any study in this subject and any correlation (not even cause and effect) and I cant find any. It seems the information came from Jay McCaman and his book. I could not find information around the author either.

I would expect a research paper that shows the ppm of calcium (from a soil test), the percent coverage of dandelions in a plot, the size of the dandelion. All of this at different levels of calcium and then amending a few of the plots with gypsum (calcium) and see a reduction in the qty of dandelions and the size.

The closest thing I found was nitrogen, KBG and dandelions from 1998. It makes sense since a thicker lawn stand will make it hard for dandelion seeds to grow. http://archive.lib.msu.edu/tic/mitgc/article/199829a.pdf

I do get that some soil conditions will make one plant thrive while other will suffer (poor drainage vs high sodium), but I don't see how a weed can be cured by calcium or other nutrient.


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## osuturfman (Aug 12, 2017)

One of my favorite reads on cultural control of dandelion.

https://www.blog.asianturfgrass.com/2011/04/fertilizer-and-weeds-at-park-grass.html


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