If you’re on a quest for the perfect lawn, you’ve probably already heard of scarification. And you’ll know just how important it is as a weapon in your armoury.
But if you’ve never actually done it before, you may have lots of questions. One of the most basic is when to scarify your lawn in the first place. Is there a right or wrong time of the year? A particular kind of weather to aim for? And how long should your lawn have been in place before you do it?
Fear not – we’re going to answer all these questions and more! And by the time we’ve finished, you’ll be fully equipped to scarify your lawn with confidence. So let’s get started!
What is scarification?
Scarification is the process of removing dead grass – known as thatch – and other debris from your lawn. It can be done either manually with a wire toothed rake, or with a mechanical scarifier. The latter come in either electric or petrol-fuelled versions, and they make the job considerably easier.
The teeth of the rake or scarifier are pulled through the grass, hooking out the matter that gathers at the base. This allows light, air and moisture to get to the soil, giving your grass all the nutrients it needs.
At first sight, a lawn after scarifying looks a bit of a mess. But give it a few weeks and the grass will come back stronger and healthier than before.
So that’s what you do. But when do you do it?
Leave young lawns alone
Scarifying is quite a brutal process. You’ll be tugging spikes through the grass and putting pressure on the roots. So don’t do it before your grass is well established.
If you have a brand new lawn it’s unlikely to need scarifying for a while in any case. There simply won’t have been time for thatch and moss to build up.
It’s not a job that needs to be done regularly – once a year at most. Once every two to three years is fine too. Just be prepared for it to be harder work when you get around to it.
If you’ve waited a year before scarifying a new lawn, you shouldn’t have to worry that the roots aren’t fully embedded. But if you want to be one hundred per cent certain, there’s a simple test.
Just give the grass a tug. If you feel it pulling at the soil, don’t scarify. The roots aren’t strong enough to cope. But if the grass snaps in your fingers and the ground stays firm, you’re good to go.
Spring or Autumn – When to Scarify Lawn in the UK?
You want your grass to be able to recover from scarifying as quickly as possible. The optimal time to scarify is therefore in conditions where your grass is growing quickly. You want the weather to be warm, but not too hot. And you want plenty of moisture in the soil.
In the UK, that means either spring or autumn are the best bets. There are advantages and disadvantages to both.
1. The case for spring scarification
Grass grows quickest of all in the spring months, so it’s an obvious choice for scarification. There are plenty of showers to keep the ground moist, and the sun is warm but not too strong.
It’s also a good choice for those who want to enjoy their garden at its best in the summer months. Give the grass time to recover before the temperatures rise, and you’ll have a lush green lawn to laze on with a cold drink. Don’t leave it too long to do the work – March or April are ideal.
But there is a downside. Whilst grass is growing vigorously in spring, so are weeds. Scarification will uncover bare soil in your lawn, providing a ready seed bed for the little blighters.
If you do scarify in spring, it’s therefore best not to do it too hard. A lighter rake will clean out the worst of the thatch, but won’t offer an open invitation to weeds.
2. The case for waiting until autumn
While in spring the garden is waking up, in autumn it’s preparing to go to sleep. You’ll still benefit from relatively warm temperatures, particularly in September. And there’s likely to be plenty of rain for your grass.
And because weeds will be dying back, they won’t be able to get a foothold in a newly scarified lawn. So if you want to give your grass a more thorough treatment, now is the time to do it.
There are, however, some circumstances in which autumn isn’t the best choice.
If your lawn is in a shady spot, you’ll find the grass begins to thin out naturally at this time of year. Scarifying it then can be too much of a shock to the system. You could find yourself with bare patches that take ages to recover, and may even require reseeding.
This goes double for any areas which are shaded by overhanging trees. Falling autumn leaves are a real problem for grass, providing a barrier to air and water reaching the soil. And they also offer shelter to pests, increasing the risk of disease.
So if your lawn is shady, especially if the shade comes from trees, wait for the spring. The grass will be much better equipped to come back strong. Just be aware that you may need to keep an eye out for weeds. Applying fertilizer with a weedkiller component afterwards can prevent them getting a grip.
Choose the right day
Moisture on the grass will add friction as you scarify and can lead to the grass tearing. That can let in bacteria and disease, so wait for a dry day. Afternoons are often a good bet. Any dew from the night before will have evaporated, and new dew won’t yet have formed.
It’s also a good idea to try to avoid windy days. If you don’t have a scarifier with a collection box, you’ll be raking up piles of thatch all over your lawn. The last thing you want is a gust of wind blowing them back over the surface of the grass again!
Make sure you’ve prepared properly first
Getting the best results means building in some time for proper preparation before you scarify.
The first step is to mow the lawn. Nice short grass will mean you require less pressure to pull through the rake or scarifier. And you’ll be able to see what you’re doing better too.
Plan to cut the grass at least a day before you scarify. Up to a week before is fine too. As with when you scarify, you’ll want to do this in dry conditions.
That means, of course, finding two dry days no more than a few days apart. The British weather isn’t always reliable – but check the weather forecast to give yourself the best chance.
Now that your grass is nice and short, take a good look to see what you’re dealing with. In particular, examine the ground to see whether there’s any moss.
If you spot some, it’s a good idea to apply a dose of moss killer before scarifying. That will help to prevent spores from being released as the moss is raked out. And that will give you the best chance of avoiding brand new moss growing back as soon as you’ve finished!
If you’ve left your new lawn for at least the recommended year before scarifying, this will be fine. But don’t apply moss killer if your lawn is less than six months old. It will be too strong for the grass and is likely to damage it.
You’ll also want to avoid applying other kinds of weedkiller within a few weeks of scarification. That’s for two reasons.
The first is that scarification can interrupt the weedkiller before it’s finished its work. So more robust weeds may be able to recover.
The second is that you may need to overseed any bare patches on your lawn when you’ve finished. If weedkiller is still present in the soil, it can interfere with the germination of the grass seed.
Finally, before you start to scarify, check that there’s some moisture in the soil. While dry grass will make your task easier, dry soil will mean your lawn struggles to recover. If you’ve had light rain over the last week or so, it should be fine. Just press your fingertips to the earth to check.
Now you’re ready to scarify!
We hope you’ve found our guide to when to scarify your lawn useful. Choose the right time of year, and a day with the right conditions, and you’ll get good results. And you’ll find the whole process a lot less of a strain too!
Remember, autumn is best for more intense scarification, but not if your lawn is shady or overhung by trees. If that’s the case, do the job in spring instead. A lighter scarification is fine in spring too. Just don’t go mad, or you may find you end up with lots of weeds amongst your grass.
If in doubt about when to scarify, remember: the key is to give your lawn the best possible conditions to recover quickly. That means warmth, moisture and light. And treat new lawns with care – it’s best to avoid scarifying for the first year.
Good luck – and enjoy the fruits of your labours with a healthy green lawn!