Organic Lawn Renovation: BurnOut II VS Nature's Avenger

Today is the first day of my organic lawn renovation project and it starts off with killing off my existing lawn and weeds. I didn't want to use RoundUp or other glyphosate based herbicides so it seemed like a good opportunity to compare two of the available organic weed and grass killers I mentioned in my post on organic RoundUp alternatives to see how well they work.

I reached out to St Gabriel Organics and Cutting Edge Formulations, the makers of two organic herbicides which I had been investigating, who provided me free samples for my review.

As I posted previously, there are three sections of the lawn I'm renovating and will apply BurnOut II to half of each section and Nature's Avenger to the other half.

This is a multi-day process so bookmark this post as I'll be updating it with the results. I'll also be tweeting when I update this post so please follow me on Twitter.

Table of Contents

• About The Products
• Day 1 - Initial Spraying
• Day 2 - Spot Treating Missed Areas
• Day 3 - Initial Observations
• Day 7 = One week Observations
• Day 8 - Mowing Raking Final Spraying
• Day 9 - Dethatching

About The Products

BurnOut II

BurnOut II is a product from St Gabriel Organics, a company that has been in business for over 30 years selling organic products. Their first being Milky Spore Powder for organic grub control.

BurnOut II is an OMRI Listed (Organic Materials Review Institute) weed and grass killer with the main active ingredients of Clove Oil and Citric Acid.

The version I'll be using is a ready to spray formula that comes in a 1 gallon bottle with integrated pump sprayer.

Nature's Avenger

Nature's Avenger comes from Cutting Edge Formulations which was founded in 2003 by the CEO of a successful lawn care company 

Nature's Avenger is also an OMRI Listed weed and grass killer with the active ingredient of d-Limonene which is derived from oranges.

For perennial weeds and grasses the recommended dilution is 1 part Nature's Avenger Concentrate to 3 parts water which is the mix I'll be using.

Conditions

Lawn

A full description of the areas to be spread can be found on the first post regarding my lawn renovation.

There are 3 sections:

• Section 1 - Receives full sun and has a lot of different weeds and a mix of grasses.
• Section 2 - Receives partial sun and only has a bit of crab grass at the edges. The grass is mostly Kentucky Bluegrass.
• Section 3 - Receives little sun and has no weeds. The grass is fine fescue.

I've divided and marked each section in half. Sections 1a, 2a and 3a will be treated with Nature's Avenger while Sections 1b, 2b and 3b will be treated with BurnOut II.

Weather Conditions

Both these products work by making the plant vulnerable to the elements in one way or another and work best when the weather is warm, sunny and humid.

I have not watered these sections of my lawn for over a week and there has been very little rain. About 0.10" total fell 2 and 3 days ago and conditions should be warm and clear for the next few days.

Today's high will be 93 degrees. Outside temperature at the time of application was 85 degrees and there wasn't a cloud in the sky and little wind.

Warning

Even though these products are organic they contain strong ingredients and you should follow all instructions on the label when it comes to use and safety precautions.

Day 1 Application

Based on recommendations from St Gabriel Organics I'm going to follow an application schedule of initial spray, spot spray 2nd day any missed areas, spot spray any regrowth on the 7th day.

Today is the first day of the application as well as the first day of my renovation and I have sprayed each section with it's respective herbicide.

BurnOut II

The bottle of BurnOut II came premixed in a pump spray bottle. It's convenient, especially if you don't have a good pump sprayer but as with other limited use pump sprayers like the one BurnOut II came in, it's not all that great.

There is very little adjustment with the tip. I could only seem to get it to give a small spray or a stream and not much in between. It works well if you're only using it to spot treat some weeds here and there but for covering a large area I'd recommend the BurnOut II Concentrate in a better pump sprayer. I was able to use the built in pump sprayer but it was very slow.

I started application of BurnOut II at 12:00pm once temperatures climbed above 85 degrees.

BurnOut II has a strong smell of cloves which might make you crave a bowl of rice pudding or reminisce about that cute girl you met at a college party wearing all black, looking bored and smoking a brown cigarette.

It took me about 20 minutes to spray all the areas and I could start to see results almost immediately. The photo on the right shows Section 1b below the yellow line that was sprayed with BurnOut II. The area above the yellow line (1a) had not been treated yet.

The various grasses and weeds are starting to die, at least in some areas. I wonder if the poor sprayer resulted in uneven coverage as there are some areas that were sprayed that showed little symptoms of stress. It has only been a few minutes. As the days pass and I spot treat more grass and weeds will hopefully die.

I also sprayed a few weeds that were growing within the stress cracks in the concrete. Below is a picture of crabgrass that was sprayed with BurnOut II. It started turning brown almost immediately. The picture was taken about 30 minutes after spraying as well as a clover looking weed in a similar area

Nature's Avenger

I received Nature's Avenger as a concentrate. It needs to be mixed with water. There are three recommended dilution ratios.

• 1:6 for young annual weeds
• 1:4.5 for tougher annual weeds
• 1:3 for perennial weeds

To tackle the perennial weeds and grasses I opted for the 1:3 mix and used my 2 Gallon Smith Garden Sprayer with a fan tip to apply it to my lawn.

Nature's Avenger's main ingredient is d-Limonene which is a strong degreaser derived from oranges. It is an ingredient that I've seen used in more eco-friendly/biodegradable concrete cleaners and adhesive removers. It smells a bit like oranges but the clove scent from the nearby BurnOut II treatment still overpowered it.

It also seems to dissolve styrofoam. I was using a styrofoam cup to measure out the appropriate amounts of water and concentrate. By the time I finished pouring out the first cup of Nature's Avenger the cup had fallen apart. 

One of the nice things about Nature's Avenger was that it leaves a white coating for a few seconds where it was applied which makes it easy to apply without missing any spots.

I began the application around 12:45pm when the temperature was around 86 degrees, skies were still clear and there was little to no wind.

To the right is a picture of Section 1a (below yellow line) shortly after application of Nature's Avenger. The grass and weeds are already starting to turn brown. Many leaves have shriveled, others have become darker.

The dutch white clover in this area seemed to be particularly susceptible to the application. Some of the wild violet looks injured, others look fine and I paid extra attention on those weeds to make sure they were thoroughly covered.

Nature's Avenger also did a good job with weeds growing where they shouldn't, such as in between concrete cracks. Below is a close up of some crabgrass that was sprayed with Nature's Avenger only minutes earlier. It didn't take a long time for it to show signs of stress.

Thoughts for Day 1

I'm glad that I'm using safer products to kill my existing lawn and weeds. I know this process can take multiple days but with the mode of action I was expecting move visible results within the first day. I'll spot treat tomorrow and post more pictures. Both products have performed well on many of the weeds, especially the new ones that were growing in cracks in the concrete but not all the weeds are showing signs of their demise nor some of the grasses, particularly tall fescue. 

Sections 2 & 3 which have less direct sun show signs of something happening but it's hardly noticeable in photos.

I'm a little nervous but haven't given up hope yet.

Day 2

Things look a lot better (worse for the grass that is) today. There is significantly more damage to the grass and weeds. The plan for today is to spot treat areas that are still green.

Weather Conditions

Like yesterday, today is a hot, sunny day with little wind. I started application of both BurnOut II and Nature's Avenger at 11:00 and 11:20 am respectively. Temperature was 85 degrees with 45% humidity. There are some clouds in the sky but they do not block the sun.

When I planned this process the weather was going to be clear throughout but forecasts indicate that some rain might be coming earlier than I expected. I'm not sure what impact that might have.

Crabgrass In Cracks

Both BurnOut II and Nature's Avenger seem to do a good job dealing with weeds that grow in unwanted areas such as the stress cracks in concrete joints. Below are photos of the same weeds photographed yesterday. One sprayed with Nature's Avenger, the other with BurnOut II. Neither received a second application today. Both show significant damage to the plant.

BurnOut II

Nature's Avenger

Section 1

Section 1 receives full sun and both products seem to be doing well killing both the grass and weeds in this spot. 1a was treated with Nature's Avenger and 1b was treated with BurnOut II. There was still quite a bit of green this morning but that may be due to poor coverage. 

The photos below show Sections 1a (Nature's Avenger) and 1b (BurnOut II) separated with a yellow line from two different angles. The photos were taken about 2 hours after the spot treatment that was sprayed today.

For some reason the first angle show more green than the second angle. Both products appear to be doing a good job killing off both the grass and weeds with BurnOut II showing a little better results. We'll see how things look tomorrow after today's application has some more time to work.

To get a better sense of the effectiveness of these products here are two shots which include portions of the neighbors untreated lawn. Note the brown spots in the second picture are due to issues in the lawn and not overspray.

Sections 2 & 3

Sections 2 & 3 receive less sun than Section 1 due to a tree that casts shadows throughout most of the day. Section 3 receives less sunlight than section 2. Section 3 was planted with a fine fescue mix while 2 is mostly Kentucky Bluegrass.

At the end of Day 1 there seemed to be little damage to the grass and even after today's application there is still significant green in the lawn. More grass has died and all the crabgrass in section 1 has been damaged.

Because there was so much undamaged grass these areas were resprayed with their respective organic herbicides. Nature's Avenger for the 'a' plots and BurnOut II for the 'b' plots. The photo below was taken roughly 2 hours after today's respray.

Closeup Photos

Below are some overhead, close up shots for each section to give you a better indication of how each section is going.

Thoughts For Day 2

I'm feeling a little more confident in these organic herbicides than I was yesterday. Both BurnOut II and Nature's Avenger work faster in heat and direct sunlight and I'm hoping in a few more days the grass in the shadier sections as well as some of the green spots in the sunny areas will begin to desiccate.

Before I started this project I had concerns that it might be too big a job for either BurnOut II or Nature's Avenger. I'm still on the fence but they're both working well so far.

Day 3

As per the plan, I'm not spraying anything today. The weather isn't as warm as previous days. Mid 70's for most of the day with a high of 80 this afternoon. Humidity is higher, in the mid to high 60's with a small chance of rain this afternoon. They sky has been overcast all day but a little bit of sun is starting to peek through. All photos were taken at around 9:30am.

Section 1

One of the nice things about the overcast conditions is it allows me to take better photos that give a more accurate representation of the condition of the lawn. See my post on garden photo tips for more info.

Section 1 is in full sun throughout the day and both products have done fairly well in browning the weeds here. As you can see there are still quite a few patches of green throughout the lawn. These are grasses that have not (yet?) been desiccated by the sprays. Section 1a was sprayed with Nature's Avenger while Section 1b was sprayed with BurnOut II.

Section 2

Section 2 doesn't get as much sun as Section 1 and is planted with mainly Kentucky Bluegrass. The shade mixed in with dappled sun made it harder to see the results of the spraying. Today's photos give a better representation. As you can see a lot of the grass remains green, likely due to the shade but there is more browning than was observed yesterday. There was some crabgrass growing on the bottom edge  in the photo which has all turned brown.

Nature's Avenger was applied to 2a while BurnOut II was applied to 2b.

Section 3

Section 3 receives even less sun than Section 2 and was planted with a fine fescue mix. There were no weeds in this section. While there is still a bit of green left in the lawn there seems to be more browning than in section 2. 

Nature's Avenger was applied to 3a while BurnOut II was applied to 3b.

Day 7

Weather

Since my last update the weather hasn't been ideal for this task. Skies have been mostly overcast and I've received about 1.25" of rain. Humidity has been high. Temperatures were good. Except for one day that was in the high 70's all other days were in the mid to low 80's.

Based on my schedule I should be respraying today but conditions are overcast while tomorrow will be warmer and sunnier so I'll hold off until then.

Crabgrass In Cracks

Both of the crabgrass weeds that were growing in concrete stress joints haven't started to turn green again. The Nature's Avenger treated one appears worse and more straw colored than the one treated with Burn Out II but both seem dead.

Crabgrass -  Nature's Avenger

Crabgrass - BurnOut II

Regrowth

This isn't unexpected but there has been some regrowth. All I've seen start to grow back is some of the dutch white clover and the fast growing, wide bladed tall fescue. I haven't seen any noticeable regrowth in the other grasses or weeds.

The idea is that the roots will exhaust their energy reserves and when I do the final spray tomorrow that should really knock them back so that the new grass seed can come in and out-compete the old grass.

I thought the wild violet would be difficult to kill but there are no signs of it coming back.

Clover/Fescue BurnOut II	Clover Nature's Avenger
Fescue Nature's Avenger	Wild Violet Nature's Avenger

Section 1

Section 1 receives the most sun and has the most foliage death. There has been some regrowth in both the BurnOut II (1b) and Nature's Avenger (1a) treated sections. Both seem to kill the grass and weeds well but I think the integrated pump sprayer in the BurnOut II bottle didn't give me great coverage. When I respray tomorrow I'll pump the BurnOut II into my garden sprayer first.

I kicked some of the grass with my boot and it exposed soil. I yanked at a random bit and the grass pulled out easily roots and all. When I start working the plots getting it ready to reseed I'll know if it's like that throughout. Whether this is a result of the spraying I don't know but it was something I observed.

Section 2 & 3

Sections 2 and 3 didn't have many weeds and the area receives a lot of shade. Neither product did particularly well even after 2 full sprays. There has been significant killing of the grass blades since I first sprayed but the areas that get more sun have done better. I should have split up these sections a little differently because the A sections get a little more sun as does the bottom portion of the Section 2 photo..

Thoughts on Day 7

I was hoping for a little better performance in the shadier plots but I wasn't surprised that I didn't get it. To be honest, both performed better in the shade than I expected.

The tall fescues that are coming back in Section 1a and 1b concern me because even though these are grass plants, and I'm replanting with tall fescues, the existing tall fescue grows very fast and is one of the grasses I really hate in the lawn. They also have a very wide blade and coarse texture. Hopefully one more application will knock them out long enough while the Jonathan Green lack Beauty grass I'm planting germinates. It should start coming in within a few days. If I was planting a slower germinating Kentucky Bluegrass I'd be more concerned.

Day 8

As expected today was hot and sunny. Instead of just respraying the lawn as planned I decided to mow the lawn at the lowest mower setting. I had to work it down a little at a time or it started to bog down. I put the bag on my mower but still had to go over the lawn with a spring tine rake to clear the dead grass clippings.

After seeing how the tall fescue started to grow again I thought it best to clear as much room as possible to make sure the spray got down to any new growth and to the crowns of the plants. I went over the whole area with a light mist of spray but made sure any spots that had green were thoroughly coated.

The tall fescue seems to be tough to kill. There are some spots in Section 1a and 1b I might have to dig out by hand as I prepare the soil tomorrow unless they take a turn for the worse overnight.

I ran out of BurnOut II before I could retreat all the sections. I had enough left to retreat Section 1b and parts of 2b but not 3b. The grass seed needs to go down this weekend so I had to use Nature's Avenger on parts of 2b and all of 3b.

For both products (and both types of sprayers) I only got about 450-500 square feet per gallon of ready-to-spray product. Instead of using the pump sprayer in the BurnOut II bottle I used my Smith Garden Sprayer. Using the fan tip I had more control of the spray and was getting more consistent coverage. Had I used the garden sprayer from the beginning I might not have run out.

Section 1

Here are photos of Sections 1a (Nature's Avenger) and 1b (BurnOut II) about 1 hour after mowing short, raking and respraying. 

After mowing and raking I was happy to see just how much bare soil there was. Some of the areas were scalped by the mower but some of the grass pulled out while lightly raking. Including the roots. I noticed yesterday that some of the grass was easy to pull out. I'm not sure what might have caused it as it's not an advertised feature of either product.

Yesterday I noticed some of the clover coming back. Other than the tall fescue it was the only other foliage to recover from the spraying that I noticed. Having sprayed and mowed today it's died down again. Since my grass seed should start germinating in less than a week if I'm diligent with my watering it should start taking hold before the dutch white clover comes back.

Section 2

After mowing and spraying there seemed to be a little more dead grass today but there's still quite a bit left. I believe the majority of the grass in this section was Kentucky Bluegrass since that's what I used to overseed in previous years but there may have also been some older perennial ryegrass and fine fescue. Because this area gets less sun I don't think either product was as effective as in the sunnier sections.

It looks like I might have to do something to remove more of the green grass manually before I reseed.

The bottom part of 2b in the photo was the last bit of BurnOut II was used. Above that and in section 2a I used Natures Avenger.

Section 3

This morning section 3 looked like it had less green grass than in previous days, even before mowing and raking. This area gets even less sun than section 2 which caught me by surprise. The grass consists of fine fescues. One reason the grass might have been more susceptible than section two is that it was all new grass that was planted a few years ago. The other sections contain grass that has been there for decades.

After mowing and raking it looked pretty ready for reseeding. As I mentioned earlier I ran out of BurnOut II and had to use Nature's Avenger to treat both sections 3a and 3b.

I was quite exhausted after all the work today and didn't take the best photo of section 3. I'll post more photos tomorrow showing what it looks like about 24 hours after today's final spray application.

Day 9 

This update is a few days overdue. The work that followed the spraying was harder than I anticipated and really tired me out.

After the final spraying there was more dead grass in each section though the shady parts of the lawn still had a bit live grass in them. Here's the updated picture of Section 3 from day 9 before any further work was done to the area that shows section 3a better.

Dethatching

After mowing down the grass on Day 8 and raking up much of the dead grass clippings it looked like it would be a good idea to dethatch. I had earlier noticed that some of the grass pulled up easily roots and all and dethatching would not only allow for better seed to soil contact but it would also help clear out some of the grass plants that have been sprayed.

When I normally use my thatch rake on my lawn it pulls out the thatch as well as ground ivy but generally leaves the grass intact even on an aggressive setting. This time dethatching exposed a lot of soil as can be seen in the picture on the right. 

The thatch rake cut through a lot of the dead grass leaves and even pulled out a lot of the grass roots as I was hoping. It didn't take any more effort than is normally required when dethatching.

After dethatching the grass that hadn't been injured by the sprays is easier to spot. Overall I'd say each spray achieved roughly 95% defoliation in the sunny areas and 90% defoliation in the shady areas.

Tall Fescue and Dutch White Clover

The fine fescues, kentucky bluegrass was very susceptible to the herbicides as were all the weeds. The tall fescues were more resilient especially the very fast growing weedy lookig tall fescue. Some of it may be the unimproved K-31 tall fescue but some of it also looks like it might be orchard grass.

Dutch white clover was the only weed to start showing signs of life one week after spraying (it's now over 2 weeks since I started spraying and none of the other weeds have come back. 

There was clover and tall fescue in Section 1a (sprayed with Nature's Avenger) and Section 1b (Sprayed with BurnOut II) and there was no difference that I could detect in how the clover and tall fescue was affected.

After dethatching it became apparent why the clover and tall fescue wasn't as damaged as the other grasses. Below is a picture that includes dutch white clover on the left and tall fescue (maybe orchard grass) on the right and a bit of other tall fescue throughout.

Dutch white clover spreads via stolons and little stems grow off that stolons where the leaves grow. The stolons grow on top of the soil and it looks like within or under the thatch layer. This causes two problems with these organic herbicides. First it's location makes it hard to thoroughly coat the  stolons to injure it and second the thatch and taller grass helps shade it from the sun which reduces the effectiveness of the sprays. The colors didn't come out great in the photo but the  stolons were still green and healthy looking but all the leaves had been desiccated and crumbled off the stem.

A lot of the  stolons came up during dethatching but others had to be hand pulled. They came up easily with a slow steady pulling (not yanking) that hopefully got most of the root out. After amending the soil and keeping up with a good fertilization program the clover shouldn't be a problem once the new grass comes in.

The nasty Tall Fescue and/or orchard grass and other ugly clumping grasses that were in my lawn also had quite a bit of their structure in the thatch layer and even under the soil. 

The leaf sheaths were thick, almost woody and new leaf tissue could be seen growing out of them. In addition fescue is a clumping grass and where ever there was blades poking out through the top of the soil there was a mat of thick leaf sheaths and roots about the size of a hamburger patty underneath.

Some of the tall fescue seemed to be of an improved variety but most of it was not very attractive. It was the main reason I wanted to do a lawn renovation.

Had I left the tall fescue as-is in the lawn it would have surely come back. It already started coming back. Once I amended the soil and began watering the new seed it would thrive. The thick clumps underground would also make it difficult for the new grass to develop good roots.

The tall fescue had to go and neither spray eradicated it. Section 1 is the only section where I had this unimproved tall fescue so my plan is to dig it out. Using a heavy duty hoe like this Ames True Temper 2 Pronged Weeding Hoe I dug out all the tall fescue plants by driving the hoe underneath the clump and pulling it up. I then went through the area with a bow rake to collect as much of the grass plants as I could. I wound up digging up all of section 1 because the tall fescue was so prevalent. It's something I was hoping to avoid because it can bring up weed seeds that were too low in the soil to germinate but I really don't want that unimproved fescue.

No Earthworms

Every time I use my thatch rake on my lawn I see earthworms coming up with the thatch. Not this time. I didn't see a single one in any of the sections. Not even when I was digging the tall fescue out of section 1. Weeks earlier I did see earthworms in the garden beds along section 1.

I did however see about 10 grubs in total and 2 wireworms.

UPDATE: I passed by the renovated section at night about a week after my last spraying and decided to pull out my keychain flashlight and have a look. Right there in the middle of the beam of light was a fat red worm dragging a bit of dead grass blade back into it's hole! I did a little more reading on worms and it seems that earthworms go into a form of hibernation called estivation when temperatures are too hot or dry. There was little rainfall during the time I first sprayed and I didn't irrigate the lawn in these sections much before spraying to begin with. The sprays themselves likely didn't harm them but not watering the lawn for so long drove them deep underground to wait for better conditions. 

Soil pH

This one threw me for a loop. I used this consumer model soil tester that Encap was giving away this year. I tested it in a few different areas and compared it to other results and it seemed to do pretty well.

Considering BurnOut II's ingredients consist of a few acids I had expected the soil pH to drop at least in the 'b' sections where BurnOut II was sprayed. I checked a few parts of each section and the readings were all about the same. The pH actually increased making the soil more alkaline.

I had anticipated spreading lime before seeding but now it looks like I might need to add some sulfur instead. Until I amend the soil with compost and recheck with other means I'll hold off applying anything.

Thoughts For Day 9

I'll know more once the new grass starts coming in but so far I'm pretty impressed with both Nature's Avenger and BurnOut II.

Both did a superb job killing weeds that grew within the driveway and sidewalk stress cracks with only one spraying.

Both also killed all the weeds that were in the lawn. There was some regrowth of the dutch white clover because the stolons were in the thatch layer where they were protected from the sprays and sun but the one weed I thought would be a tough one to hurt was wild ivy and I haven't seen any signs of it coming back so far.

Both were effective in the sunny areas and did a respectable job in the areas that get around 4 hours of sun a day. The areas that get less direct sun than that didn't do as well but more than 90% of the grass was killed. Tall fescue was tough because a good bit of the leaf was covered by thatch and soil. The faster growing tall fescue would have already re-established itself before the new seed would have begun to germinate.

If you don't have a lot of tall fescue or don't mind if some of it comes back it seems both these products are a pretty good alternative to RoundUp (glyphosate) for a lawn renovation. At the very least it will provide considerably more coverage than just overseeding would.

Having used the products now I'm starting to formulate some ideas of how the process could be improved. Mowing low and dethatching would definitely be incorporated prior to the first spraying.

For general weed killing as far as spot killing younger weeds in driveways, sidewalks, patios, pavers, garden beds and lawns I would absolutely recommend these to anyone that doesn't want to use glyphosate.