What Are Chafer Grubs?
Chafer grubs are the larvae of chafer beetles and feed on dying plants or plant roots depending on the species of chafer grub. The ones that feed on dying plants aren’t a problem but those that eat plant roots can cause a lot of damage to your lawn.
There are six species of chafer grubs and the ones that you should look out for are the Garden Chafer grub and the Welsh Chafer grub.
They usually have thick, cream-coloured bodies with a darker shade toward the ends and have heads and six legs that are brown coloured. They can range in size between 10mm and 15mm long and usually lie in the soil curled up.
Adult chafer beetles lay their eggs a few centimeters down into the soil in early summer and are laid in small groups of no more than six and between two and four weeks to hatch. They like to lay their eggs in turf because it’s easier to burrow into and this is how chafer grub infestations start.
Chafer grubs can live in the soil for up to five years and spend this time eating away at the roots of grass and plants which causes dead patches of lawn to pop up over time. They stay in the soil all year round and in the colder months, it digs deeper then returns nearer the surface to feed during warmer months.
Because chafer grubs live so long, they can multiply quite quickly and before you know it there’s multiple generations of chafer grub living beneath your lawn.
In the spring, when the chafer grub has eaten enough, it will grow a hard shell and transform into a pupa that it will stay in for four weeks. Then the shell will crack, and the adult beetle digs its way out of the soil to take flight.
How To Know If You Have A Chafer Grub Infestation
Luckily, it is easy to tell if you have a chafer grub problem. A sign that you have an infestation is if you notice the grass on your lawn becoming yellow and loose which is caused by the roots being eaten by the grubs.
To make sure this is a symptom of chafer grubs, remove a small bit of soil and check to see if there are any grubs in it. To get the best result you should do this when it is warmer, so the grubs come closer to the surface.
Grubs are a favourite snack to a lot of wildlife so if you see animals such as foxes, crows and badgers digging about your lawn then it could be because they are enjoying the chafer bug buffet.
How To Get Rid Of Chafer Grubs
You can get rid of chafer grubs by applying an organic control product called Turfsolv. Turfsolv is completely organic and pet and animal-safe. If the damage isn’t too bad then look to apply Turfsolv initially, then 3 days later, and then finally once per month right through the year. Turfsolv, alongside nematodes, are our only defence currently, as most pesticides are now banned in the Uk.
Nematodes can be applied in a watering can, and then will need repeat watering for 2 weeks following application. You’ll get better results if the lawn is aerated before applying nematodes too. You can buy Nematodes on eBay, Amazon (affiliate links) and many other websites.
If the lawn is in a severe mess then you’ll need to be thinking about either repairing or replacing your lawn depending on how severe the infestation is and how big your lawn is. If it is small then you are better off replacing the lawn altogether.
To replace your lawn, the first thing you need to do is apply a weedkiller that has glyphosate in it to the whole lawn. This will kill the remains of the grass seeds and weeds so that they do not grow back through the new turf and this will cut the chafer grub’s food supply. You will need to leave this weedkiller in for two weeks as it works its way down into the roots.
After the two weeks have passed, the lawn should be completely dead and ready to be removed. This can be done with a spade if you have a relatively small lawn but if you have a large space to cover then you can hire a turf cutter. Once you have removed the turf, leave the soil exposed for a few days so that the birds can pick off the chafer grubs.
Make sure to turn the soil over every day to expose more grubs. Keep doing this for about a week and the chafer grub population should have a good dent in it.
If the birds in your area are not doing as much work as you had hoped, you can sprinkle some chafer grub killer into the soil which is an effective way to kill the grubs and is safe to use.
Now that all of the chafer grubs are killed, you can now prepare the ground for new turf and be proud of your lawn once again.
If you would rather repair your lawn instead of replacing it, you should start with mowing it and scarifying it which will remove leftover dead grass which will make a better base for growing new grass. Scarifying your lawn also helps to open up the soil for the next step.
Once this is done, you have to get rid of the chafer grubs. You can do this with nematodes which will infect the grubs with bacteria and kill them. Nematodes will also keep on top of the chafer grub population as well because they will reproduce throughout the year.
The negatives to using nematodes is that sometimes they can cause leaves to be distorted and twisted if they are feeding aboveground.
To avoid this, you can use a chafer grub killer instead which is a very effective way of killing them without using any chemicals. Before applying the grub killer, make sure it is warm as it is when grubs are closer to the surface and the ground is moist.
The next step in this process is to apply good quality grass seed so that the patches where the dead grass was being filled in and the lawn can start to look lush and healthy again.
Adding fertiliser afterwards will help the grass develop a healthy root system and get your lawn looking as good as new in no time.
How To Prevent Chafer Grubs
After all that fuss, you likely wouldn’t want to go through a lawn repair or replacement again. To prevent another chafer grub infestation from happening, keep on top of your lawn care by mowing it regularly but keep the grass a little bit longer during the summer as this will make it harder for beetles to lay their eggs in the soil.
Beetle eggs will die if it is too dry so you can the eggs by not watering the lawn as much during the summer, try only to water it once a week. By applying nematodes during the spring and summer can also keep the chafer grub numbers down.
Finally, as mentioned earlier get some Turfsolv on the lawn and apply it once per month for best effects. It’s 100% non-toxic and organic!
