Crabgrass and Fall overseeding - Ask Extension
I applied Quinclorac 75DF to kill the mature crabgrass and other weeds one week ago in my sun drenched front yard. Not all have died. I have heard m...
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Crabgrass and Fall overseeding #885266
Asked September 14, 2024, 4:08 PM EDT
I applied Quinclorac 75DF to kill the mature crabgrass and other weeds one week ago in my sun drenched front yard. Not all have died. I have heard mixed opinions about removing the dead plants, but cannot imagine that a grass seed could germinate when planted into this mess. I need some help and advice please, Can you help please???
New Castle County Delaware
Expert Response
Hello,
It looks like you had decent control, but I have seen better. Did you add a methylated seed oil (MSO) to your spray solution?
How do you plan on doing the seed establishment? Aerification, slit seeder, tilling, raking etc??? But, yes seed will germinate as long as seed-to-soil contact is good. It is best to eliminate any weed competition prior to establishment as this will produce best results.
Thanks for your response. I used baby shampoo as my surfactant. After most of the crabgrass and many other weeds died, I did power raking to scrap the soil and remove some of the dead weeds. I can now see the soil. I realize the power raking could increase crabgrass seed deposits, but in some areas, I couldn’t see the top of the soil. Can’t see seeds germinating through that dead weed vegetation. There are still weeds that appear to be alive.
I did a soil test and found neutral ph, but depleted nitrogen, potash and potassium.
My plan is to apply starter fertilizer, water it in and use some top soil as a top dressing, then over seed, but would love any advice you can offer.
.
Sent from my iPhone
Sent from my iPhone
On Sep 16, 2024, at 11:29 AM, Ask Extension wrote:
I should also point out that the soil seems pretty compacted and I feel plug aeration is needed. Agree?
Sent from my iPhone
Sent from my iPhone
On Sep 17, 2024, at 7:15 AM, Mark Hart wrote:
Thanks for your response. I used baby shampoo as my surfactant. After most of the crabgrass and many other weeds died, I did power raking to scrap the soil and remove some of the dead weeds. I can now see the soil. I realize the power raking could increase crabgrass seed deposits, but in some areas, I couldn’t see the top of the soil. Can’t see seeds germinating through that dead weed vegetation. There are still weeds that appear to be alive.I did a soil test and found neutral ph, but depleted nitrogen, potash and potassium.My plan is to apply starter fertilizer, water it in and use some top soil as a top dressing, then over seed, but would love any advice you can offer..Sent from my iPhoneOn Sep 16, 2024, at 11:29 AM, Ask Extension wrote:
- As stated on the label, methylated seed oil is the only surfactant recommended for quinclorac. Results are mediocre, at best, when using other surfactants.
- Where did you send your soil sample to for analysis? Can you send me the results? <personal data hidden>
- Aerification would be a good idea to improve seed germination. I would also recommend aerifying in 2 different directions.
- For best results, remove or rake out any dead plant material remaining.
- Soil dressing will help smooth the surface and improve seed-to-soil contact.
- Use improved varieties of tall fescue. (not Ky 31)
