TestDIYOrganic

Good seed to soil contact is about as important as watering grass seed to get good germination rates when overseeding. Core aerating and dethatching are both recommended practices when you plant to overseed. But is it better to aerate or dethatch when overseeding?



I've done both in the past and in my opinion, dethatching will give you better results. This post contains my recommendations for dethatching and overseeding.





Core aeration will help if you have compacted soil and will get more water and nutrients down into the soil to help encourage deeper root growth. But it doesn't expose much soil. A rate of 16 holes per square foot is a normal aeration rate. The holes are only 1/2" in diameter and at that rate you're only creating holes in about 2% of the lawn. If you leave the plugs on top of the lawn instead of raking them up, you'll get a little bit of soil exposed there too but it's not a great place to germinate seeds. It only increases the percent of exposed soil slightly sits on top of a layer of thatch and dry out quickly.



When the grass seeds start to germinate in the holes, there is also the possibility that they get choked off when the soil starts to fill in.



Dethatching on the other hand will expose more soil by removing the thatch layer. The tines of the dethatcher also cultivate the soil giving it a nice tilth which will help the seeds embed in the soil rather than just lay on top. This is similar to raking your vegetable garden to loosen the soil before planting seeds.



The dethather also helps groom the grass roots close to the surface. This will give the new roots more room to grow.



Another benefit is that using the thatch rake helps me find crab grass and other prostrate grassy weeds. Because of the prostrate growth, the stems/blades are longer than grass. When I rake them the longer blades are easier to spot. It's hard to describe but you'll know it when you see it. When you come across these weeds, just keep your Weed Hound and remove it.

Dethatchers

I don't have a very large lawn area and I also prefer whenever I can to manual tools like the thatch rake pictured right. Being "green" seems to go hand in hand with organic gardening and lawn care but that's not the reason I do it. I just think it's good cardiovascular exercise. It also works out your arms, back chest, legs and core. Sometimes when I'm dethatching I'll count each stroke (in my head so people don't think I have OCD) and then switch hand positions on the rake every couple of dozen strokes but usually I lose track if I have to stop to pull a weed and just try and switch as evenly as I can.



Otherwise you can rent a dethatcher, sometimes called a power rake, buy a Dethatcher Attachment if you have a Mantis Tiller or a tow behind dethatcher if you have a riding mower.

Overseeding

Once the dethatching is done, remove the thatch and place it in your compost pile if you have one. Then spread a good quality grass seed. Galaxy Kentucky Bluegrass Blend is a good choice for many sunny areas here in the northeast. If you have shady areas review my shade grass seed recommendations.



After the seed is down a topdressing of 1 yard of compost for every 1,000 sq ft is recommended. It will help keep the seeds moist, provide nutrients... just improve germination in general. The compost will also add organic matter to the soil. In between seeding and topdressing you can go over the seed with the back of a rake, use a roller or find some other method to help get the seed down into the soil. I don't have a roller, I'm not sure a rake works that well when overseeding so I just water the lawn for a few minutes to wash the seed down into the soil. Then water it in again after applying the compost.



If you have really fine compost that doesn't have a high moisture content, you can sometimes spread it with your spreader. If that's not working out I like to just grab a small bucket full and sprinkle it over the lawn. It's slower than pushing it around with a rake but it won't disturb the seed as much either.



This should give you very good results so you can fill in thin or bare areas in your lawn.

Your lawn can benefit from core aeration, especially if you have compacted soil. Renting or hiring someone to aerate your lawn can be expensive and purchasing a manual lawn aerator can be time consuming. There must be a better way?



There are products that claim to be liquid aerators that you spray on your lawn with a hose end sprayer. These include LazyMan Liquid Lawn Aerator, Aerify Plus and Nitron A-35.



But how well does liquid aeration work?



The first bullet point on the Aerify information page states that Aerify "Eliminates the need for mechanical aeration" (in bold) followed by "Reduces soil compaction". The claims for LazyMan Liquid Lawn Aerator are similar. Nitron A-35's makers don't go so far as to say it's a replacement for mechanical aeration.

The makers of Aerify go on to say how their liquid aerating product is better than mechanical aeration.

So what's in these back saving products and do they work?

The ingredient that is in all these products is a type of surfactant. In some it's ammonium laureth sulfate or some other anionic surfactant. The use of these products (alkyl sulfates) are common and chances are you come in contact with them (hopefully) every day. Surfactants make "water wetter" by reducing the surface tension of water. At least that's how Mr. Wizard explained it when I was a kid. The surface tension of water is like a little skin that holds a drop of water together like a balloon. These particular substances are also very good at creating foam.



You're basically spreading shampoo on your lawn. Expensive shampoo. The claim is that around 1 oz of product in 1 or more gallons of water spread over 1,000 sq feet, then watering in will reduce soil compaction. Does it seem reasonable that 1 oz of shampoo can do the same or better job than pulling around 20,000 4" deep 1" diameter cores? That doesn't seem likely to me and I'm someone who spreads cornmeal on my lawn!

University Studies on Liquid Aeration

The Colorado extension office has a page that agrees that there is no proof and that liquid lawn aeration is not effective. (Emphasis added.)

While it is difficult to ascertain what is contained in these products, a few have been shown to contain liquid humates (essentially liquid organic matter) and soap-like materials like sodium lauryl (or laureth) sulfate. It is simply wishful thinking to believe that a highly diluted solution of either of these applied to a compacted soil will in any affect soil bulk density. There is no indication that ANY of these products has ever been scientifically evaluated for effectiveness.



Simply stated, there is no "chemical" substitute for physical remediation of soil compaction - namely the traditional core cultivation techniques that have been used for years on all types of turf areas. At best, these "wonder products" might provide some minor degree of wetting agent effect - and nothing more. Wetting agents increase spreading and penetration of liquids across surfaces and into or throughout surfaces.

These two other publications from the North Carolina Cooperative Extension Service and Oregon State's Cooperative Extension indicate that surfactants can be effective under certain conditions where the soil is very hydrophobic. Hydrophobic meaning the soil will not absorb water and instead will bead up on the surface like on a freshly waxed car. "Water does not bead up on wettable soil; therefore, unless beading is present, a surfactant or wetting agent would be an unnecessary expense." So unless your soil has a shiny factory finish, surfactants don't seem to do too much.



This USGA Turfgrass and Environmental Research Program Study on water retention in golf greens(pdf) included humic acid. The conclusion was that it didn't do anything to aid water retention in the tested greens which is contrary to claims that humic acid will help increase the water retention of sandy soils. Though humic acid may have other benefits to the soil, I can't find any studies indicating that it can be used as an alternative to core aeration.

Just Use Humic Acid?

It seems like unless you have a particular condition, that sounds pretty rare, these products won't help with soil compaction but the humic acid and other nutrients some contain can have a positive effect on your lawn. You can get humic acid on it's own which will probably give you similar results and be cheaper.



I actually have some Aerify PLUS which I purchased based on some advice I received but I didn't see any noticeable difference in compaction. I got it before I started looking into the product. Later on, I core aerated with the Turf Hound aerator and that seemed to really help the grass as the holes allowed water and air to get deep into the soil where the roots are.



Aerify Plus is more than just a surfactant, it contains Humic Acid, Kelp and other elements and micronutrients. I plan to use it up after I found out that alkyl sulphates, such as ammonium laureth sulfate, are easily biodegradable and don't cause any harm to water. Once I finish the bottle, I'm just going to get humic acid and use kelp meal (Organica Kelp Booster) instead.



Maybe even a liquid kelp. At 2 tsp/gal/1k sq ft that 35oz bottle can do the 5 suggested applications to 21,000 sq ft. Need to be careful though because it contains a bit of potassium so make sure not to over apply and keep track of the other potassium you're putting in your lawn. Potassium isn't something that leaves your soil quickly, so you don't need to apply too much.



Basically, this is the way I see it. Wetting agents and surfactants are like tapping a stuck jar against the counter or running it under hot water. It will help get a stuck jar open but it's just a waste of time and water if the lid isn't stuck. If your soil isn't hydrophobic, your lid isn't stuck!

I picked up a Hound Dog Products Turf Hound Aerator
last year and now that I've used it a few times I wanted to give my review and some pointers.




The Turf Hound is a manual lawn aerator that is great for small yards or for getting into areas where a gas powered aerator can't. It is a very affordable and environmentally friendly way to aerate your lawn. It is better than other manual aerators because it pulls plugs out of the lawn instead of poking holes. Just like a gas powered core aerator would.



Gas powered aerators are expensive. A few hundred for a tow behind unit if you already have a lawn tractor, or a few thousand for a dedicated unit. You can also hire someone to do it, but that usually runs $75-$100 and up depending on the size of your lawn and your location.



If you've read some marketing about liquid lawn aerator prooducts, read my comments on whether liquid aeration works or not before spending any money.

Do you need to Aerate your Lawn?

Aerating your lawn helps loosen compacted soil and allows air and nutrients to get in deep into the soil. It helps your lawn roots grow deeper which will give you a lusher, more drought resistant lawn.



You should pull up a section of your lawn and see how deep the roots grow. If they don't grow deep, it could be an indication that your lawn is too compacted. It could also mean that you are watering your lawn too often and not deep enough. The best way to water your lawn is deeply and infrequently.



Another indication is if you have moss growing on your lawn. Moss tends to grow on compacted soil, but it could also be a result of improper pH. The good news is that aerating your lawn is good and you can do it every year. With the Turf Hound being very affordable, you don't have to worry about the cost after you purchase it.

When should I aerate my lawn?

The best time to aerate your lawn is in the fall. Over the winter the soil will loosen and the holes will get filled in.




You can also aerate cool season grasses in the early spring before your lawn starts waking up from the winter. It's not ideal since the summer heat will stress the lawn and since more of the soil and roots are exposed because of the holes, it can dry them out.

Since you have a lot of soil exposed after aeration. It is also a good time to overseed. And since you'll also have some soil plugs laying around, it makes it easy to test your soil conditions such as pH, nitrogen, phosphorous, and postassium levels. The kit pictured to the right is an affordable way to do those tests. Soil testing will help you plan your fertilization needs. Just grab a little bit of soil off the bottom of the plug. These aren't as reliable as a lab test from your local cooperative extension office but some people seem to have had success with them.

Initial Impressions

I think the Turf Hound aerator is a great tool to have. My large isn't huge and I'm able to do it all manually. I would highly recommend it to anyone looking for an alternative to gas powered aerators or anyone looking to save money this season. Lets face facts, with the economy how it is, it's best to try and save where you can.



It is incredibly easy to use and durable. I hit a few roots and rocks that I couldn't push into and there was no damage to the Turf Hound whatsoever.

Turf Hound aerating Tips

Wear work gloves when using the Turf Hound. If you're planning on aerating a substantial area it's a good idea to wear a pair of work gloves. In a 1,000 square foot area, with a goal of 18 holes per square foot, you will be pulling up on the Turf Hound 9,000 times. That's a lot of friction on your hands which can easilly lead to blisters or other injuries.



The soil should be moist but not too wet. If it's too wet, the cores will get stuck in the holes. If you're using the aerator and you don't see the plugs being ejected out the top, your soil may be too moist. Let it dry out a little bit. If you find it's too hard to aerate, your soil is likely too dry.



Check for clogs. Every once in a while, stop and check to make sure the plugs are coming out. If they're not, the holes in the aerator could have clogged up. I keep a 10" plastic dowel with me to push out any plugs that might get stuck. If you're working with good soil moisture content, this won't happen frequently. This is very important, because if the holes get clogged, you're not aerating, you're actually pushing the soil down and compacting it. The exact opposite of what you want to accomplish.



Try not to bend over while using the Turf Hound. I'm over 6' tall and I wish the turf hound could be just a little bit taller. If I use two hands on the Turf Hound I wind up having to bend over, which makes using it a little more difficult. If I keep one hand on it, just to steady it, and just let the weight I apply with my foot make the cores, it is a lot more comfortable.



Be careful of rocks and roots. If one side of the aerator hits a rock, root or other obstruction that prevents it from going all the way into the soil, it will become uneven and if you're not paying attention, can cause you to lose your balance. What I found best was to keep both feet planted firmly on the ground until the Turf Hound dug in, then lift my other foot so my weight was on the Turf Hound to help drive it in further.



Clean and dry it after you are done. Just hosing it off should be sufficent. The Turf Hound is coated with a rust proof coating, but I found that it started to wear away after it's first use. So I make sure I let it dry in the sun before I put it away.

How To Use a Turf Hound Aerator

The Turf Hound couldn't be simpler to use. Place your dominant foot on the bar between the two cores. Stabilize it with your had and you're pretty much just walking your way to a healthier lawn.



It doesn't take very long. I was able to do about 100 sq ft in about 10 minutes, using a tight hole pattern. It's not very difficult, but I did break a little sweat. It wasn't strenuous, but as I mentioned earlier, if you're tall, you want to try and keep from bending over. I'm going to try and figure out if I can attach something to it to extend the handle. I found that I only needed to use my hand to help stabilize it, so I was able to use one hand, which kept me from bending over.

Holes Per Square Foot

The Turf Hound doesn't come with much instructions and contacting Hound Dog didn't really clear things up. I did a lot of searching before using the Turf Hound to see what would be appropriate.



It varies based on your soil conditions, but somewhere between 9-20 holes per square foot seems to be a good number to shoot for. Typical gas powered lawn aerators do around 9 holes per square foot, and you would need to run it twice from different directions and you would get 18 holes per square foot.

The tines in the Turf Hound are about 6" appart. That's not very close spacing, so I found it best to overlap each pass, so the holes from the second pass wind up in between the holes from the first pass. You can see an example in the picture on the right.



To make things simple, I determined how many plugs per square foot are created based on overlapping the passes and the spacing between pairs of holes in each pass.



A hole every 6" on each overlapping pass will give you 8 holes per square foot.



A hole every 4" on each overlapping pass will give you 12 holes per square foot.



A hole every 3" on each overlappling pass will give you 16 holes per square foot.



The nice thing about using a manual tool is you can adust as you go. If you feel an area needs more aeration, you can space your holes closer, if it needs less, space them further appart. As you go along, you'll feel differences in how easy it is to push into the ground, which will give you some indication of how compact the soil is.



When you're finished, just leave the plugs on the ground. They will break down after a little while.



Now's a good time to water your lawn deeply if you're not expecting a lot of rain. It's also good to overseed with a good quality grass seed. New seed will require light, infrequent watering to help it get established. It will also keep the roots from drying out now that they are exposed.



If you don't mind a little manual labor, and prefer to not pollute with a gas powered aerator, the Turf Hound is a great bargain and you can do lawns up to a couple thousand square feet in a day.