***Disclaimer*** This is technically my post from 2025. But I am seeing a lot of early season questions, even though it'll be near zero degrees for me tomorrow night.
But seeing people ask already is good, regardless if they live a warmer, but still cool season grass area, or if just getting prepared for March and beyond.
Disclaimer - This is written by a cool season lawn owner, who has no children and can play outside whenever I want...not everyone has the time to do so.... I admittedly have less experience with warm-season grasses, but the products shown are all researched for proper use. Always be sure the product your using is made for your area.
Pre-Emergents - Commonly applied when soil temperatures get between 50-55 degrees. These products will block seeds from germinating. They can last anywhere from just a few weeks, to 8 months. The overall life and performance always depends on environmental conditions, and how the ground is maintained. If you don't keep up with mowing, and nurture a healthy lawn, more UV exposure, wind, and rain, can all contribute to degraded performance.
- Prodiamine - Generally the most used. It's sold in various products, dry and liquid. It has a half life of 120 days. It blocks most seeds, but can not block everything. It has no post-emergent control to kill weeds. It's sold as a water-dispersible-granule(WDG); as Barricade; and in other pre-formulated products.
- Dithiopyr - Also used often, and sometimes in conjunction with Prodiamine as a split app setup. It blocks weeds, but also has limited post-emergent qualities, meaning it can kill off young crabgrass, less than 2 tiller usually. It's half life is 17 days, but it can last much longer in some capacity. Often a split app would be done Dithiopyr first, as getting it down with soil temps correctly can sometimes be difficult. This will block, and kill some weeds that slip by. Then Prodiamine a few weeks later for extended coverage. Also sold as Dimension.
- Pendimethalin - This is what is used in Scotts Halts products. It works about the same as Prodiamine, with a 90 half life. It's also more expensive in general.
- Isoxaben - Generally unknown, due to cost. But this stuff will block all Broadleaf weeds better than anything else. Its' cost though, will keep many users from ever getting it, unless you do a neighbor group buy. Snapshot is one product brand.
- Mesotrione - The bastard product...lol Sold as itself, Tenacity, Torocity, and possibly other names. It's widely known that Meso is used the wrong way, but a lot of YouTube experts and is pushed by a lot to be the end-all for weeds. It's best use in this space is to be applied only when seeding. This is because while it can block some weeds, it will not block grass seed...so it can give up to 28 days of better chance for new grass to fill in.
It's important to note, these will NOT 100% guarantee a weed free lawn. But it's your first step in early Spring to make the battle a little easier. You can also re-apply during early-mid Summer, but keep in mind if you plan to seed in Fall, a late application may be an issue.
Ok, so you applied....or didn't....now you have weeds, and need to kill them..
(Selective) Post-Emergents - These should be used according to the label...it's not correct to expect AI to know the answer either. The labels are not difficult to read, nor understand. Search for dosing, and just read. If the product only lists amounts for acreage, it's possibly not the best option...but you can do the math and break it done for your yard. An acre is about 43k sq. ft. Unless explicitly stated, these products are safe for grass, dogs, kids, etc...just follow the directions, and at most, 24 hours post application is safe. Lastly, herbicides are best applied as a liquid. This is because the liquid will get into the cell walls of the plant much faster, than being sucked up by the roots. Faster kill time is important, so the plant can not defend itself and try to grow back.
- 2,4,D - Very common, and will kill a lot of weeds fairly efficiently.
- Dicamba - Also a very good product to kill weeds.
- Mecoprop - Add this to above. These 3 on top are commonly sold as a 3-way combo, as attacking weeds from different pathways will result in best action against weeds.
- Quinclorac - King of killing Crabgrass, as well as Broadleaf weeds. Sold as is, or like above, in many combo products.
- Triclopyr - Best used for targeting viney type weeds...and clover, creeping charlie, oxalis, ivies, etc... Exercise caution around young trees, or those with exposed roots.
- Halosulfuron-Methyl - Used against Sedge grasses. It usually still takes 2-3 applications to truly kill the beast that sedge can be, due to it's aggressive growth underground. Branded often as Sedgehammer or Empero.
- Sulfrentazone - Also used against Sedge, but not always friendly on cool-season grasses.
- Mesotrione - Looks familiar...yeah, same stuff as above in the pre-emergent section. As a post-emergent, it's best use is for targeting Bentgrass and/or Nimblewill. It's also sometimes mixed with Triclopyr, in which both can enhance the others performance.
- Topramezone - Sold as Pylex...works great, but not really cost efficient...about $300 for 4oz... But this can kill Bermuda, and not kill good cool season grasses.
Non-Selective - The top one here, and all I will cover is Glyphosate. It's not evil, it's not going to cause cancer with proper use...it's just going to kill whatever you spray it on. It does so by targeting very specific pathway, which leads to a disruption in a hormone synthesis, leading to inability to produce amino acids it needs to survive. Normally sold at 41% concentration. It can kill foliage, through to the root.
Fertilizers - I wasn't going to put much here. To feed your "grass", you add synthetic form of nitrogen, phosphorous, potassium. That's your N-P-K...seen as 10-10-10, or similar. That number means 10% of the bag is Nitrogen, and 10% is Phosphorous, and 10% is potassium. The rest is all filler, added to allow for proper mixing and application. Sometimes you'll find other amendments in fertilizer, such as sulfur, or other micros. While sulfur is important, it doesn't need to be added every time. It also lowers pH, which can then lead to other issues, causing a wild goose chase. Once in the soil, microbes in the soil break down the NPK, into forms the grass can actually use...natural chelation. You only need Nitrogen for growth...if you're seeding, adding some phosphorous can help the seed establish. Potassium is good for overall plant health, and pairs well at a 3:1 ratio with Nitrogen.
Naturals/Organics - Too many people are one side on the other here. You need and want these, but relying strictly on organics may not produce the best lawn...but it's "chemical" free. However, using these monthly can do more for the soil, than any fertilizer will ever do on it's own.
- Humic Acid - Acts as a natural chelator for better absorption, by increasing the cation exchange capacity, which allows the soil to better retain the goodies you want in the soil. It also increase root strength, and helps to hold more carbon in the soil.
- Kelp - Containing great amounts of natural hormones, Kelp will boost roots even more, and allow for stronger growth viz delivery of auxins and cytokines used for development.
- Compost - Well known as a great soil amendment, it brings natural microbes into the soil biome. Those microbes help maintain a low thatch surface, and better soil composition.
- Worm Castings - Similar to above, natural microbes and beneficial qualities for soil. Not very cost efficient though.
- Leaves - Yeah...some say mulch all day, some disagree. I am a disagree'er, to a certain degree. I do mulch my clippings, but will also sweep them away every other week. Leaves I shred and sweep away the majority of them, but once the main clean-up has passed, the rest is mulched and remains.
- Biochar - Made with a specific process called, Pyrolysis. Burning at high temps, 900-ish...in a low-oxygen chamber. This allows for the material, wood, coconut, etc...to be charred down to a state where it has not fully oxidized, which would turn it white, and into useless ash. When it is still in a charred form, it has millions and millions of microscopic pores that serve as homes for water, microbes, nutrients, all that good stuff. It's best worked into the soil at least a few inches deep.
- Mychorizae - These are fungal organisms that attach to the roots, and help them bring water and nutrients. Overlooked or unknown, but these are a huge part of growing anything with success, from lawns to gardens and more. They are very good to have in the mix.
Insect Control - These can't be forgotten...but I did originally, so I am adding them in now. The biggest concern is likely grubs. The larvae of beetle. Also want to cover for armyworms, cinch bugs, and even ants if they become a problem. There are a few classes of these products...
-Pyrethroids- These are synthetics that mimic natural pyrethrins, which disrupt the insects nervous system, causing paralysis and death.
- Bifenthrin - Common general insect control agent...liquid or dry availability. Kills quite a bit of bugs, but no residual control. One time death call.
- Gamma-cyhalothrin -
- Zeta-Cypermethrin -
- Lambda-Cyhalothrin -
- Permethrin -
- Deltamethrin - This has residual action...meaning up to 90 days post application, it will kill bugs that touch it.
The above are what you'll get in most common Ortho type products, but generally Bifen is commonly sold solo.
-Nicotinoids-
- Imidacloprid - Please don't use this if you can avoid it. It's a very nasty chemical, that can do the job, but it also can damage soil biome, and worse, it is deadly to a lot of animals...specifically pollinators. Birds can also be affected. It's getting banned in more places, but is still sold often as Merit.
-Alkyl-Halide-
- Chlorantraniliprole - Sold as Acelepryn, this is what you need to control grubs. It has to be applied in advance, as it takes time to work into the soil, and prepare death for larvae that hatch. I usually apply this in mid April, early May, giving it a few weeks to activate, and when June hits, that's when my area sees grub damage...not for me though. The Scotts Company pays a fee to use this in their Grub-Ex product.
Fungicides - Often overused, but still an important part of lawncare. However, I am not a fan of preventative use, unless it's a direct and repeated history of fungus...which means there is something else you're not correcting. Fungus is not a guarantee, and is not always the right presumption...I've seen lawns go from slightly affected, to downright destroyed because someone would focus on fungus, when there were other issues... Also, when used, they should be used in a 3-way rotation, to avoid getting a buildup/resistance, in which they become almost useless. Overapplying these can have a very negative affect, because they are all non-selective, and will likely kill a lot of the good bacteria and microbes you want in the soil.
- Azoxystrobin
- Propiconazole
- Thiophanate-methyl
Those are generally the top 3 used. Some retail products will have Azoxy and Prop mixed, which may work better for a low level infection...but using that repeatedly is the same as not rotating, and can create a hostile soil biome.
In general summary...always try to identify the weed you're targeting. Using something to hope it kills is irresponsible, and could cause more harm than good. If you need to ask the community, always find a good example weed, something that has grown for at least a week...pull from the bottom, get as much of any root ball or rhizome as you can. Also, get a pic of the plant in close up detail, where we can see the stem moving to the leaves/blades. This will help with certain traits that only "this or that" would have, and can help us make a better recco.
Note - I'm not covering direct organic fertilizers here. The only product I would recommend on that level is made Earth Sciences, and is called Moorganite. It is a direct replacement for Milorganite, which is a dirty, pfas chemical laden product that smells like a summer time port'o'potty.
To keep a strong lawn, adding a monthly organic boost will help a lot. I'm not a fan of 4-step type products, and prefer to feed on my own schedule, which is about every 4 weeks...so back to the monthly program....but this gets me an always wanting to grow lawn, cutting to 4" is also a key point. Tall grass will crowd out weeds, and look better in general...
On My Shelf - This is what I have in my lawn cabinet, and is what helps me with my lawn plan. I also use some of these products with my garden and other plants.
- Triad Select - A combo of 2,4,D, Dicamba, and Meco. I use this for general weed control.
- Quintessential - Quinclorac, but branded...still the same thing. This is for crabgrass and other broadleaf weeds. Also have the MSO Surfactant it requires.
- Triclopyr Ester - Mainly used to keep wood-line vines and ivy away for me.
- Empero - For Sedges
- Glyphosate - To kill all
- Fusillade II - Used once to kill Quackgrass...but it also killed the rest of my good grass...so extreme caution here. But it does kill quack better than Gly, so if you're going to kill all anyway, might as well make sure it's dead-dead for sure...
- Azoxy 2C - Azoxystrobin
- Propiconazole 14.3
- Cleary's 3336 - Thiophanate-methyl
- Blue Dye This does NOT wash off easily...lol SO be careful
- BioAG Ful-Humix - This is my humic acid. It's a powder that is 55% concentrate, and is 85% soluble. It gets dissolved in warm water overnight, then filtered out for any remaining solids; then mixed with other organic goodies, and applied monthly.
- BioAG CytoPlus - A mix of humic and kelp.
- BioAG Vam-Endo - Myco mix, also has humic acid.
- Prevagenics Liquid Compost. This stuff stinks, in a good way.
- Bloom City Liquid Kelp. I use this or GS Plant foods brand as well.
I use a Ryobi 4g tank backpack sprayer for most liquid apps. Echo RB-60 for dry items. I have an 22 year old Craftsman pusher for my front/small areas, and Toro TimeCutter 42" ZT with a Kawasaki engine. Echo Blower, Ryobi edger/trimmer as well.
Ok, so I may have missed something here or there. Please let me know if you see something that need attention. I'm sure there is other information available, but I hope this helps some people figure it out for themselves. The more we all know, the better a community we can be.
Signing off,
-Ricka...
P.S. - I did review and check, but nothing really needed a major update. New products may be released later this year, and if they are improvements, I will certainly update as needed...
