10

I put down some spray Ortho concentrate weed killer almost 2 weeks ago. Now many of my weedy areas are turning brown and look like they are drying up (grass still looks ok).

What do I do now? Will the weeds simply disappear? Should I rake them out or pull them up?

Also, the weed killer doesn't seem to have gotten all the weeds in the first round: what is the best course of action for getting rid of the remaining weeds? If the best option is more weed killer or different weed killer, when will it be ok to apply that?

enter image description here enter image description here enter image description here

10

You have to wait 3 weeks or whatever is on the label to overseed. Exactly what did you use for herbicide? Obviously broadleaf weed killer. The only reason you even have that problem is because your lawn is not healthy, lots of bare ground to allow weed seeds to get plenty of sun, moisture and fertilizer to out compete your grass crop.

We need to help you turn this around. Pesticides/herbicides are never necessary. They are like a Band Aid on easily prevented problems. Yes, rake the dead material up and out of your lawn. Mow no lower than 3". This is one of the best ways to stop germination of weed seeds. Aerate by pulling plugs of soil out of the lawn and leave them where they lay. Begin a process of watering where you water very deeply (4") and do not water again until you are able to see your footprints in the grass crop. That means the blades are not able to stand back up as they are not turgid. Then and then only do you water deeply. Never water in between deep watering and those footprints. What this does is cause weed seedlings to die for lack of water, your grass to grow deep deep roots thus becoming drought tolerant and able to thrive while weeds die. Mowing 3" minimum gives your grass plants the photosynthetic ability to feed those genetically programed large root systems and have plenty of energy for all other botanical processes. Plants make their own food.

Fertilizer is as important as water and sunlight for all plants under our management. Also you need to test the pH of your soil. If it is below 6.5 you need to lime your lawn. Do not lime unless you have a test. Never ever water a little every day. Try not to use Scott's or Ortho products. I am not some 'organic or au natural lover'...chemicals are chemicals no matter how they are produced. Filler material is another story.

I found after decades of lawn installation and care that this 'organic' fertilizer for lawns was phenomenal. The words organic and natural and nutrients are so misconstrued I have a hard time using them. I have only used Dr. Earth's Lawn Fertilizer (proper formulation for the time of the season) and I don't get amazed by fertilizer results. But I was truly floored and impressed. So much so I promote this 'organic' lawn fertilizer. This truly is worth the extra money, you have to use more of it than the synthetics, it is extended/slow release which I think is far healthier for grass, takes longer to see results, lasts longer and I could not believe the difference. Doesn't have to be Dr. Earth but look at the labelled ingredients. There is also bacteria for decomposing thatch.

Fertilizer is normally applied 4X per season for cool season grasses. Different formulations for each application. Fast release sells to humans who insist on immediate results. Extended release means healthier grass and longer lasting chemicals that grass has to have to be vigorous. You use only 2 maybe 3 applications per season, not 4 so the price is mitigated. But so worth the extra money and extra passes over your lawn.

And if you follow this advice (look up other question answers for lawns on Stack Exchange Gardening and Landscaping as well) you will not have to deal with weeds and that expense and that work. Weeds are truly over rated in the garden world. Knowledge is all one needs to deal with weeds and severely reduce any worries about them.

Do not apply any more herbicide. It is not necessary nor is it helpful. If people knew basic management tenets of gardening, lawns... pesticides and herbicides are never needed. And I can say this from decades of being a licensed commercial pesticide applicator.

  • 3
    This is a fantastic answer. It addresses several of the OP's questions. Specifically, should they be pulled or raked? And what should the poster do now? This answer looks beyond the immediate question (when should I dump more weed killer on it) and tries to address the actual problem (how do I get a healthy lawn). It got my +1. – GargantuChet Jun 6 '17 at 0:00
  • Whoa, thank you @GargantuChet. A rare honor. Made my day for sure!! – stormy Jun 6 '17 at 0:25
  • 1
    @Jeutnarg I answer each question individually. Sometimes I don't spend enough time checking the information in the question, my bad. But this wasn't one of them. There was no assumption of weed killer and there is but a select group of chemicals used for killing dicots in a crop of monocots. Pesticide Applicator licensing never ever talks about brands and rarely the composition of pesticides. Lots of chemistry but zero promotion of any formulation 'value' over another. We are taught religiously how to read that label 5X. We are taught basics and prevention. IPM. – stormy Jun 6 '17 at 17:44
  • ...Integrated Pest Management. So one never has to use pesticides (pesticide is the general term to include; miticide, herbicide etc.). To get licensed one has to pass massive tests. There are huge seminars to teach what one needs to know to be a pesticide applicator. Then there are wonderful continuing education seminars that are required. Luckily the people in charge of licensing are the Cooperative Extension Service of a large University who also teach Master Gardening, Master composting, Master pruning and Master food preserving. Can you imagine Ortho giving classes? – stormy Jun 6 '17 at 17:50
  • Every thing one needs to know about a pesticide product is on the label. Which was the most important thing we were tested for; how to read a label and MSDS sheets that always go with a product but not included in the grocery store garden aisles. Each and every time one uses a pesticide we have to read that label 5X. Drilled into us ..anyone in the commercial realm that uses any pesticide has to be licensed. If not, they are breaking the law. I am sure Ortho and Scott's hate this program because they teach total newbies how to NOT to have to ever use pesticides. – stormy Jun 6 '17 at 17:54
7

You can rake them out or leave them there. I would not pull them out because doing so will disturb the soil underneath and get more unwanted seeds to sprout into more weeds. In terms of reapplying ortho, follow the instructions provided by the manufacturer. Are the weeds that have not died a different variety weed than the one that died? If so, your weed killer may not be effective for the weeds that did not die.

4

If you're going to use a brood-leaf (type) herbicide, always let it be. . . They function in a way, that requires them to be left alone. It begins by absorbing the material at the leaf, and despite it's seemingly having killed the plant, it's still working on killing the underlying roots. Hence, leave it be and it'll eventually, simply turn into mulch. I see you have what a lot of people in our area are calling "nap weed?" That's not it's name, but it's how it acts. It embeds and tangles itself everywhere and is actually a wimp when it comes to handling physical manipulation. e.g. if you had a dethatcher, you could rip it out while mowing. (My wife rakes it out of the places it takes over the yard, and within days, the grass is taking hold of it's former real-estate again.) Anyway, I only bring this up because its root system is exactly the same, and it returns each spring, or anytime the weather cools off long enough for it to re-propagate. If you're crop of nap-weed is like ours, you've only killed about a quarter of the underlying root system, and it'll just keep coming back. As someone else mentioned, the best thing to do is get the grasses going strong. We tried all the typical seed at the typical stores, finally went and bought a 50 pound bad of field fescue from a co-op. It comes with several variants of fescue, and a tiny percentage of of other grasses. You can see the different variations of fescues' popping up in different environmental conditions in the yard. Shady, sunny, wet, dry etc. and I think, after four years of trying, this fescue (all by itself - no fertilizers etc. needed) - is finally going to choke that nap-weed out. Good luck, it's pain of an "imported" weed that we didn't have until we started all these "great" trade deals - like the Asian beetle disaster that's destroying every plant and tree in the USA.

  • 1
    Hi Wilberstone, welcome to the site. Interesting post! You could make it even more interesting by avoiding "text walls". Do not forget to aerate your text a little, it makes it more readable. – J. Chomel Jun 6 '17 at 8:00
  • @Wilberstone Knapweed. What are you seeing that identifies knapweed in his lawn? I am very familiar with it in pastures where the most important thing is to never allow it to flower. You get two years before it flowers. Mowing regularly would never allow this thistle looking plant to seed. One of the species has a large taproot but growing from the roots is not a problem. I have a hard time seeing knapweed a problem in lawns. Mowing would prohibit competition. Broad leaf herbicide is a selective way to kill just broad leaf plants in a grass crop. The extra surface area when damp... – stormy Jun 6 '17 at 17:08
  • ...'catches' the herbicide and translocates it to the roots. Well, we haven't found the type of herbicide he used as yet. There are no plants on this planet we humans 'garden' that do not need fertilizer. Especially mowed lawns. I would never use a 'pasture' grass mix for a lawn. Those mixes do come with a few species most lawn owners would recognize as weeds. A few broadleaf plants such as clovers are often incorporated and the mix is cheap because the seed producers aren't worried about strict conditions. I only buy lawn seed that states 'zero' weed seed. That means strict conditions – stormy Jun 6 '17 at 17:15
  • And the Asian Beetle disaster is not in anyway killing every plant/tree in the USA. Maybe we are talking two different insects. These look like Lady Bugs, they actually are good controls for the same insects Lady bugs control; such as aphids, spidermite, whitefly...the biggest headache about lady beetles versus lady bugs is the home or structures where they can stain walls/furniture and they bite. The other biggie problem are grape crops. These beetles do a great job of control but they get so numerous when the grapes are harvested, lots of these insects are processed with the grapes. Ugh – stormy Jun 6 '17 at 17:32
  • ...ruins the flavor of wine. – stormy Jun 6 '17 at 17:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.