Lawn Renovation: The myths and how to do it properly

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Written by Ian Thompson

Ian holds a Masters in Turf Management from Sydney University, has over 20 years experience working as a golf course Superintendent, turf manager, product formulation and development. We call him our resident Lawn genius.

 

Like any house renovation there’s times when you have to gut the lot, then there’s times when your lawn just needs a coat of paint. In this article we cover what type of lawn renovation is best suited to you and your lawn, what all the terminology means, the do’s and don’ts, the tips for ordering soil and the order in which to do things.

When to complete a lawn renovation

Lawn renovations can be completed at various times of the year, Spring is the best time but for warm season grasses you will get faster recovery once it’s warmer. As an example, you could renovate Couch grass in September but it will be a lot slower to recover than if you were to complete this in November.

Picking a renovation

There are a number of different lawn renovation process. Here we’re going to cover what all these terms mean, don’t worry if they are new to you. We’ve covered them in the easiest to the most complex:

 

Scalping

When/why you would do it

Scalping is the simplest form of lawn renovation, this simply means removing old leaves from the lawn to remove “dead” or older material. This material can be yellow and hard under feet, so not very attractive or nice to walk on. Removing older material allows for new growth and that new growth is nice and soft under feet.
When the lawn is super thick and some of the old leaf is still hanging around. Scalping is sometimes mentioned as thatch management but that is not accurate, thatch is below the growing parts of the lawn.

What to do

This is the easiest renovation process because it only requires a mower.
This simply involves lowering the mower to remove a lot of leaves, including the old ones. A simple scalp would involve mowing the lawn at your usual height, then dropping in 1-2 notches on the mower. An aggressive scalp is a little scary for your first time so it’s best to try this once you get a bit more confidence. This means scalping all the way to dirt and will certainly get people talking, “what have you done”.
You will need a few green bins or a way of disposing your clippings.
Once completed then its best to give it some water and a granular fertiliser like Lawn Play Renovate to kick start that fresh new leaf growth.

What not to do

Scalping is a great process but be careful not to lower the mower to fast, otherwise the mower will bog down, as the mower blades slow instead

of cutting it will simply rip out the turf. This bogging down puts pressure on the engine and other components of the mower, this could cause overheating and significant damage to the mower.

 

Topdressing

 When/why you would do it

Topdressing is the application of a thin layer of soil across the lawn. The 2 primary reasons for doing this would be to level your lawn, providing a thin layer for the leaves to grow back through. The second option is to apply a layer to the lawn that is then pushed into core holes.

What to do

Check out the soil before purchasing. One tip would be to purchase a smaller bagged product of the product you wish to buy. Check for rocks, large organic material and the percentage of different soils.
The easiest way to do this is to add some to a bottle and shake. Shaking the soil will separate all the different types of soil particles. Rocks will settle first than sand (it’s common to have a few different sized sands within a mix), organic components are next and clay will sit in the top of the water for weeks. It’s a cheap way of roughly determining textural class (the make-up of the soil).
Spread the soil evenly on the lawn and then allow to dry, once dry “rub” the soil in with a level lawn.
Once completed water the lawn.
Calculate by using your lawn size and times by 0.1 for your cubic metre measurement. Allow a little extra for areas you may go heavier and spillage.

What not to do

Low spots in your lawn can’t be raised in just one application, don’t apply a thickness greater than 10mm. For this area purchase small bags of soil, keep them in the shed and top up every time it grows through until the desired level is achieved.
Avoid soils with high levels of organic product, this decomposes and shrinks in sizes and can sometimes (in poor quality mixes) be reclaimed from green waste, have you ever thrown a weed that had seeds on it into the bin?
Avoid letting the lawn dry out, lawns will lose moisture fast when topdressing is on top due to osmosis. Rub in and water straight away to prevent burn.

 

Coring/Aerating

 

When/why you would do it

Coring and aerating involve putting lots of holes into the lawn to allow for air movement and decompaction. Coring is recommended when both compaction and thatch are an issue, however if only compaction is an issue than the use of solid tynes can reduce the compaction with less work.

What to do

Coring can be done with a small hand aerator (plus a good pair of gloves) but for an area over 50m2 we do not recommend this. It’s better to hire a core aerator or there are many great service providers that can assist in this undertaking.
The most important thing with coring is to have a “pattern” that allows for de-compaction and removes enough organic matter to make an improvement. The general rule for this is 8-10% material removal, this is calculated by the size of the holes and the number of holes per a known area. The best practice would be to use a 2” x 2” pattern for tines 10mm and smaller and 2” x 3” for larger tines.
As your tines grow in size, so much your pattern to prevent destabilising the surface.

Once completed coring the lawn, if the cores are not full of organic matter than you can run over them with a mower to break them up and rub this soil back into the lawn. If they are full of thatch and that was one of the reasons for coring then push them into a pile and pick them up.

What not to do

Don’t mow the cores back into the lawn if they contain a lot of thatch.
Overwater as the cores will get stuck in the machine and not pull out.
Simply running over the lawn and pulling a few cores will do very little for your lawn. Get a plan of how much you want to pull out and set a pattern.
Leave the holes open for weeks, Use the open holes to apply any soil amendments and then close the back up but with a good quality sandy soil.

 

Verticutting

When/why you would do it

Verticutting is the process, as the name suggests, of vertical cutting, primarily of leaves and stolons. This is generally not a common requirement when using a rotary mower but becomes a valuable process when grass is cut with a cylinder mower as rollers can lay leaves down. Have a close look at your lawn and you might have some grass leaves that are easily 20mm long while cutting at 5mm.
Another time you would verticut is if you are after a super dense and fine surface. Verticutting can be used to cut the stolons of stoloniferous grasses, creating 2 growing points where there previously was none, this improves density.

What to do

Use a verticutting mower. Set the mower up to just tickle the surface. After verticutting you should mow to remove any rubbish. Watering after is also advisable to help these newly established growing points.

What not to do

Verticutters are not made for scarifying, do not try to set the verticutter down deep into the soil, this will either pull chunks out of your lawn or destroy the mower.
This process does not remove thatch or alleviate compaction.

 

Scarifying

When/why you would do it

Scarifying is done on grasses when excessive thatch and mat have been created. This is the most effective way to remove thatch from a lawn. This can be done on its own or when excessive amounts of thatch exist and decompaction is required it can be done prior to coring as well.

What to do

Hire a scarifier and prepare a large trailer as you will pull a lot of material out.
Set the scarifier down till the blades go all the way through the thatch layer and into the soil.
Do one pass in one direction and then mow up all the debris.
Follow with a second pass if required, mow up all the debris.
Topdress to ensure a nice clean path for roots, water and air.
WARNING: Hold on tight, the scarifier will try to pull itself forward (the blades spin that way), hold onto it so that it cuts through properly.

What not to do

Set the mower at the wrong depth, make sure you are going all the way through your thatch.
Think the material will fit in your green bin.

Hopefully that’s helped break down the confusion in lawn renovation. Perfect timing makes lawn care so much easier. So, make sure you register for our newsletter for reminders.

If you’re looking for fantastic advice on any aspect of lawn care then you should follow along on our YouTube channel, LawnFlix where our resident Lawn Genius shows you how to apply, how to calculate and just generally everything lawn related.

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