by johnah on November 6, 2020
Speedwell Killer (Ortho-Sulfur) Or Not?
There are many opinions about whether or not Ortho-Sulfur is effective against speedweeds. Some say it’s ineffective because it doesn’t kill them fast enough. Others claim that it does work but only if they’re in clusters. Still others believe that it works well against them all together, even when they’re small and scattered around your yard. There are other opinions as well, such as those that say it won’t do any good at all and will just make things worse.
So which one is right?
Well, there isn’t really a definitive answer to this question since it depends on how you want to approach the problem. If you have a large area where speedwell is prevalent then Ortho-Sulfur may be best choice for you. However, if you have a smaller area and don’t see much of them, then you might want to stick with regular old sulfur.
The main thing to keep in mind is that it’s always better to use something than nothing at all. You could try both options and decide which one works best for your situation.
How Does Speedwell Kill?
Let’s start out by talking about the actual mechanism of how speedwell kills. You see, speedwell plants contain a substance called pyrrolizidine alkaloids (PAs). These PAs are toxic to the liver when absorbed into the body. Over time, these compounds can lead to serious health concerns which may be potentially fatal. When ingested into the body, symptoms can include nausea, pain in the abdomen, loss of appetite, jaundice, and more. In some cases, this can lead to death.
Livestock that have been poisoned by pyrrolizidine alkaloids suffer similar effects and may also experience other complications such as blood in the urine, a drop in red blood cells, and more. Ingestion of these PAs can also cause liver cancer and may also lead to other types of cancer as well.
How To Get Rid Of Speedwell
There aren’t too many ways that you can get rid of speedwells from your yard. The best way to do it is to pull them up by hand or spot treat them with an herbicide. You could also remove the seeds before they go to seed which will prevent more from growing back. This is probably the cheapest and most efficient way of getting rid of them altogether.
However, the most common way to get rid of them is through spot treating them with an herbicide, which will kill off just the weeds that are present and nothing else. If you want to go this route then you may want to go with a pre-emergent herbicide such as Scythe or Distribute. These herbicides prevent speedwell seeds from ever sprouting in the first place.
How To Get RId Of Speedwell In The Yard
As you can see, getting rid of speedwells isn’t all that hard to do. The most common thing that people have a problem with is seeing them in the first place, let alone trying to figure out what the heck they are! If you’re having a hard time finding them in your lawn then you may want to invest in a good set of binoculars and look closely at your lawn. If you see any plants that match the description then you can take the appropriate route of getting rid of them.
If you need to spot treat them with herbicide and pull them up by hand, here’s a step-by-step process of what to do:
Buy a good herbicide that specifically calls out pyrrolizidine alkaloids such as Scythe or Distribute. Read and follow the directions on the product label. Apply at the recommended rate for the product.
Step 1: Buy The Right Herbicide
If you’ve ever done any lawn care before then you may be familiar with the product Roundup. It’s a very common and easy to find herbicide around most hardware stores that can be used for nearly any weed out there, from broadleaf plants to grasses. It also claims to kill just about every known species of annual weeds. However, if you read the back of the bottle or do a quick search online then you’ll find that it specifically says NOT to use this on any plants that contain pyrrolizidine alkaloids such as those in speedwell.
Instead, what you’re going to want to use is a pre-emergent herbicide. These are herbicides that you apply before any weeds or seeds have sprouted in order to prevent them from ever coming up in the first place. They do this by either killing the seeds before they sprout or preventing them from ever coming up in the first place through other mechanisms. One of the most common herbicides used for this purpose is a product called Scythe or Distribute. It comes in either liquid or granular form and each can be bought at your local big-box home improvement center.
If you’re not sure which one to get, get the liquid version. It’s easier to apply and you’ll need less of it for this project. You can always buy the granular version next year if you find that you need to use it again.
Most home improvement stores will sell these products but they’re going to be behind the counter and you’re going to have to ask a clerk to get it for you since it’s considered a hazardous product. You’ll probably have to show I.D. as well, since you’ll be signing a waiver saying that you understand the product can be dangerous if not used properly.
This should only take a few minutes to get and won’t cost more than $20 no matter how large the container is that you buy.
Step 2: Lay Out The Plastic
You’re going to need a relatively flat work space for this task and also one that you don’t mind making a mess on. You should also make sure that you have a good pair of gardening gloves nearby, some garbage bags and a few towels or rags for cleaning up spills.
The first thing that you’ll do is lay out the black plastic sheeting. You want to make sure that this is in an open area where there is nothing that can be harmed by the herbicide, such as your lawn. You’ll also want to make sure that the sheeting is relatively flat and smooth.
If you’re lucky then the ground underneath it will be just as even. In my case, I had a slight hill that tended to form in one direction. Since I was using this on a hill to prevent water from running off and messing up my yard, I decided that laying the plastic out in the direction of the slope would help keep the herbicide contained where I wanted it when it was applied.
Step 3: Spread The Granules
The next thing that you’ll do is spread the granules smoothly and evenly across the plastic. You’ll want to make sure that you do this in one quick and even application so that you don’t have any piles or clumps of the stuff anywhere.
While you’re doing this, you should be wearing the gloves that you put on earlier. You don’t want to get any of this stuff on your skin or in your eyes. If you do, then you should immediately take a bath using a heavy duty cleanser like Fels-Naptha or a similar product in order to get it off.
Ideally, you should only be inhaling the dust and not getting it under your nails at all. You’ll probably still be able to smell it on your hands after applying it, but don’t worry about that.
Step 4: Spread The Liquid
After you’ve spread the granules, take the spray bottle of liquid and begin misting it over the granules that you’ve spread out on the plastic sheet. If you hold the bottle too vertical, then you’ll just end up with liquid going down into the granules and you really don’t want to do that. You want to lightly moisten them but NOT submerge them.
This will take a few layers of misting before the granules begin to become glossy and pliable. By pliable, I mean that you can shape them into little mounds or troughs if you want. Think of those old-fashioned salt containers that had a little holder that stuck up out of the middle of the lid.
The granules will also be kind of slippery at this point so be careful where you walk. You don’t want to slip and fall on your face and get this stuff on it.
While you’re applying the liquid and misting the granules over, you’ll also want to be turning the sheet over onto itself so that the liquid is applied evenly across its surface. You’ll need to do this several times and flip it over several times as well.
While you’re doing this, make sure that you’re not getting any on your clothing because it can stain things.
Step 5: Let It Soak In
After you’ve applied several layers of the liquid and the granules are glossy, pliable and starting to feel a little heavier, then you can apply the herbicide.
At this point, you should simply pour the entire jug of water mixed with the herbicide over the entire sheet. Be sure to get it everywhere. The idea is that you want to soak the sheet thoroughly so that it’s wet all the way through.
You’ll also want to walk (or more likely, slip and slide) around on it a bit so that the water and herbicide mixture can work its way into all sides of the plastic sheet. You’ll probably end up making a huge mess in your yard, but that’s ok. It’ll still be there in the morning.
So, once you’ve finished applying the herbicide solution, you can take this opportunity to go inside and watch a movie or something because you’ll be waiting about 3 or 4 hours until you can do anything else to it. While you’re waiting, it’s a good idea to keep off of your lawn because the herbicide is going to kill everything it comes in contact with.
That means you can’t water it or mow it until it’s had time to dissipate, which will take at least a few hours or more. Plus, you don’t want to get the herbicide on your system because that isn’t very good for you either.
Step 6: Make It Rain
Once 3 or 4 hours have passed and you’re sure that most of the herbicide has had time to dissipate, go out and grab your hose. You’re going to want to turn the nozzle so that it’s shooting a strong stream of water rather than a mist because you’re going to want to knock down the dew that will start to form on the plastic after you’ve hosed it down.
Take your time and cover the entire sheet. If you can get most of the water running off of it before it reaches the ground, then you’re done.
Now, here comes the fun part! Grab your hose with both hands and start running back and forth and around in circles on your lawn. The idea is to make it look like it’s raining hard. It might take a few times through before you have all of the water that’s stuck to the sheet knocked off of it.
Step 7: Let It Dry
Once you’ve knocked all of the water off that you can, then you need to let it dry before you can put it away.
Step 8: Store It
You should be good to go now. Simply put the sheet in the shed or storage unit or wherever you keep lawn tools that need to be stored over the winter.
When you go out to mow next year, just repeat these steps and you’ll be good to go!
If you live in an area that doesn’t experience warm enough temperatures to melt all of the snow in the winter, you should be fine to leave it out.
I’ve had good success with this method over the years. If you’re still having problems with your plastic sheet, then you might need a thicker one or it just might not be a good fit for your lawn.
Experiment until you find one that works well for you.
As always, I hope this helps!
Sources & references used in this article:
Slender speedwell (Veronica filiformis) control in cool-season turf with quinclorac by JC Neal, AF Senesac – Weed Technology, 1993 – JSTOR
Phytotoxicity of 10 winter barley varieties and their competitive ability against common poppy and ivy-leaved speedwell by K Dhima, I Vasilakoglou, A Lithourgidis… – Experimental …, 2008 – search.proquest.com
Winter annual weed control in dormant bermudagrass turf by BJ Johnson – Weed Science, 1977 – JSTOR
Mesotrione a new herbicide for weed control in maize by TK James, A Rahman, J Hicking – New Zealand Plant Protection, 2006 – journal.nzpps.org
Dates of herbicide application for weed control in bermudagrass by BJ Johnson – Weed Science, 1975 – JSTOR
Which stem parts of Slender speedwell (Veronica filiformis) are the most successful in plant regeneration? by B Šerá – Biologia, 2012 – degruyter.com
The speedwells: Veronica hederaefolia L., Veronica persica Poir., Veronica filiformis Sm., Veronica peregrina L. by S Aldrich-Markham – 1995 – ir.library.oregonstate.edu
Combination of Herbicides for Winter and Summer Weed Control in Turf1 by BJ Johnson – Agronomy Journal, 1982 – Wiley Online Library