How to scarify a lawn

Scarification or Scarifying is an essential part of cultured turf or lawn management. It is carried out with hand tools such as a Spring Bok Hand Rake or, for larger areas, purpose built machinery called a Scarifier. The aim of scarifying is to produce a healthy vertical type growth of desirable grasses, to improve the turf surface and appearance. Very light scarification (like with a drag brush or rake on a cylinder mower) is used simply to raise the leaves of the grass in the sward before mowing, to leave a smarter looking finish.

It helps to control the knap or grain, which can form on some types of turf. Rather more severe scarification removes dead and dying parts of the turf (thatch), thus letting in air and encouraging new growth. It also brings up stolons of both creeping grasses and weeds, such as White Clover, allowing them to be mown off. Unwanted grasses, such as Yorkshire Fog, have leaves that tend to lie flat below the height of the cut. Scarification, by bringing the foliage up to the mower, results in the grass being less conspicuous. Severe scarification tears out much of the surface growth of weed grasses such as Yorkshire Fog and Couch Grass and can weaken the plant to the point of near elimination. Many seed heads of Poa annua grow very close to the ground and light scarification, or brushing, helps to bring a large proportion of these within reach of the mower with a view to reducing the spread of this less than desirable grass. Many fine turf areas are likely to suffer from an excessive production of fibrous material at the surface, and scarification is a big factor in prevention and cure.

You can Hire Professional Quality Scarifiers Here. These can be hired for a Day, Weekend or Week. Scarification of general lawn areas is concerned with many of the same problems met in fine turf management, but with different degrees of emphasis. If a lawn had not been scarified for a long period of time, or perhaps never before, the amount of material taken out will be enormous and will surprise the hardiest of gardeners. Do not be afraid – this is an operation that can only do the lawn good. Scarification is best carried out in two or three passes in different directions, corner to corner and lengthways. For the first pass, do not set the blades too deep (approximately 5mm is ideal). On the second pass, the blades can be set at no more than 10mm and the final pass can be set a little deeper, making sure not to penetrate the soil.

All material removed from the lawn should not be put on the compost heap, as it may contain fungal spores. Scarification is best carried out in the early autumn, especially if over seeding is to be carried out as well. Light scarification may also take place in the spring, but it must be noted that the grass should be actively growing or severe damage to the sward may occur.

SCARIFYING - STEP BY STEP Check lawn for grass cover. Kill any weeds and moss (using Suphate of Iron) beforehand at least a month beforehand. Mow the lawn really low, almost scalping it to lose the volume of the grass. It will make scarifying so much easier. If the lawn is predominately moss and weeds and weed grasses, after scarification not a lot is going to be left so you will need to over sow. Scarification is best carried out when the lawn is a little moist – not too wet or too dry. Only carry out scarification when the grass is actively growing, so no later than end of October traditionally and never before grass picks up in the spring months.

If there is a serious thatch problem, the spring type tines, which are mounted freely on the axle, should be used. If vertical cutting and seedbed preparation is the target, then the more solid type blades should be used. To set the depth of the blades, go to an inconspicuous area of the lawn and start the blades just flicking the tips of the grass. Set the machine a little lower and go over this small area again. The aim with de-thatching is to go as deep as possible without disturbing the surface of the soil. The aim for vertical cutting is to go deep enough to root prune the grass, so again do not enter the soil. Only when preparing a seedbed should the soil be disturbed but the Scarifier is not a rotovator!!

When the desired depth has been determined, normally by adjusting the front roller, go round the perimeter of the lawn a couple of times as this saves throwing debris into borders and allows a turning circle at the end of a pass. Start by going up and down the lawn in straight lines. Never turn with the blades in the ground. As some machines are supplied with a grass collection box, very little hand raking to clear up should be needed. Workings on lawns that have never been scarified before will necessitate in many empties of the box so it may be easier to leave it off and clear the debris after the second pass. If the removed debris is still laying on the surface, a quick way to clear it up is to use a back-pack blower, blowing it off to a place where it can be picked up like into the centre of the lawn. The debris will however need to be reasonably dry. Use the large plastic rake to remove the bulk of the debris. You will find it easier to rake in the direction of the last machine pass rather than across it. Once the first pass has been cleared up, make a second pass but NOT at right angles to the first but on a diagonal to the first pass. You could leave the debris from the first pass on the lawn if there is not too much bulk, to save a raking process and have a serious clearing up process afterwards. Always keep an eye on the weather, as the last thing you want to happen is to be clearing debris that has become wet from light rainfall. This is why it advisable to clear as you go just in case the weather turns against you. When clearing up after scarification, whether blowing or sweeping, work in the same direction as the scarification. If clearing up at right angles to scarification, some debris will be missed.

If the plan is to blanket over seed the lawn afterwards (and after aeration) you can be cruel to be kind and really give it a good damn scarification! Don't be scared, go for it. After scarification, always mow the lawn again in different directions to the scarification. When scarifying, keep the machine as straight as possible, as it will leave stripes as with mowing. To follow - Aerate and Fertilise and blanket over seed and top dress with a loam. Currently at the time of posting this article, the weather in august is wet so you might be able to start the renovation process a little earlier to take advantage of the available soil moisture but the lawn will look a bit of a mess for around 6 weeks until the new seed germinates.

If you want some more information on the Types and causes of Moss, take a look at an earlier post on the subject and Controlling Moss with Sulphate of Iron

Comments

[Emily]

Hello
I am a novice gardener, and help my (octogenarian) parents with their v large garden. (about 1 acre, lawn possibly a third of that, they also have a grass tennis court) . One of my jobs is to mow the lawn.
It is severely thatched/mossed. and has never been scarified before, so far as I know, although my father has tried a few different things. There was no obvious moss problem until about 15 years ago.

I have some idea now of how to scarify, but am not sure WHEN to start. I think I have left it a bit late for this year? could I be doing anything else around this time to start the process (I'm thinking a little at a time, slow but steady-ish, might do the job...???)

Reply - Sound like you have a big task! Too late for this year now. In the spring when the gound is firm and dry, so after a few good windy days, mow the lawn down to lose the volume of the lawn as this makes scarifying so much easier and the mower is best suited to do this. Get it down to as low as you can with the mower then leave for a few days and hit the moss hard with a garden sprayer and soluble iron. Leave two weeks then mow down again to the original level you mowed it a few weeks earlier and scarify with a good scarifier in as many directions that you have time to manage untill you can get no more debris off it. Rake/blow the large debris amount. Mow again in a few directions to get it nice and trim and aerate and over seed it with new grass seed.

Type any of these key words into the blog and also the words Lawn REnovation and you will come up with the methodology to follow. We will email you this link direct. Good luck!

[Kathleen Fitzgerald]

Hello
We have just scarified our lawn and wish know should we now fertilise it. With something like Feed and Feed?
Kathy

Reply - No, but fertilise it with a straight fertiliser and over seed it too. No weed killer or moss killer this time around.

[playground mulch]

Scarification is a very important operation. In spring (and autumn for that matter) scarification is best combined with other operations, like top dressing, seeding and applying fertiliser.

Reply - thank you. We totally agree.

[Richard]

I laid a brand new lawn a couple of years ago (turf) after much preparation - rotavating, heeling in etc etc. The lawn has begun to suffer from quite a lot of worm casts, and has become really quite lumpy underfoot. Can you suggest how I can regain the pride and joy I strive and work so hard for?

Reply - you have the same lawn dilemma as others. Control the worm casts by visiting www.castclear.co.uk for a worm cast deterrent product.

[Lawn Lover]

Hi
I am a franchisee for a lawn care company
To assist in year round turnover the company advise us to do a moss tratment at this time of year November / December, followed by a scarifacation in January/ early Febuary and a hollow tine core in late Febuary early March with the first feed of the year in March
This seems to contradict all advise on this and other sites, please advice me
Thanks
Lawn Lover

Reply - Please don't get us going on this topic as those companies that we write about their poor turf cultural practices and certain time of the year get quickly upset when we state thay they are doing it incorrectly against the advice of many a tru turf professional.

We think that you should take your case back to your Franchisor and ask them why they are asking you to perform treatments and mechanical operations in the non growing season.

We would love to hear your updates on this issue.

[angela]

Hello,

Do you advise scarifying wet grass or should it be done when it is dry?.... my lawn was not scarified for 54 years, I did it last year for the first time, it's still a mossy messy but hugely better. I'd removed a whopping 16 black bin liners of 'moss'. I'm a gardening novice. I've talked myself into the idea that the moss will come up easier if it's wet not dry. I can't find any article that actually states the ideal weather conditions for the scarifying stage.. please can you advise asap.

kind regards

Angela

Reply - Angela, always do it when it is dry enough to mow and promising to be dry afterwards as more will come out. 'It is a nightmare if it is done in the wet. Mow the lawn down first really low as this makes the scarifying process so much easier, scarify in two or three directions and clear and mow again. Hope this helps you out.

Regards

Mike

[MINTY]

My lawn has a build up of thatch, despite light scarifying.
Can I scarify using a machine at this time of year?