February 23rd, 2021 by
Chafer grubs are the arch enemies of beautiful lawns, causing great damage. Whether you are concerned you may have an infestation or are just keen to prevent one, here is a round up of the most frequently asked questions:
What are chafer grubs?
Chafer grubs are the grubs of chafer beetles. The beetles themselves are mostly harmless, but the same can’t be said for the eggs they lay in your soil. Once they hatch, these little grubs will live underground for months, feeding on grass roots until they’re ready to pupate and transform into the adult beetles. Once pupated
What do chafer grubs look like?
Chafer grubs have a fairly distinctive appearance that makes them easy to identify. They have plump, off-white coloured bodies that curve in a c-shape. Their tails tend to be darker, and can be almost black in colour. If you’re not sure whether you’re looking at a chafer grub, check their heads – they have a distinctive orangey-brown head, and six small legs just below that.
Why are chafer grubs so dangerous for lawns?
Chafer grubs are very damaging to lawns because they eat the roots of the grass. As with all plants, destroy or damage the roots can kill the plant, or weaken it to such a stage that it can’t cope with the conditions outdoors. If there are only a few grubs in your lawn, you don’t have much to worry about as your grass can cope. If your lawn is fully infested, though, these little grubs can turn your lush lawn into a bare, muddy bog in a few short weeks.
How common are chafer grubs?
The bad news is that chafer grubs are incredibly common. They’re so common, in fact, that you likely have a few in your lawn right now. However, the good news is that individual grubs can’t do much on their own. Grass is a living thing, so it can heal minor damage to its roots if given enough time. If your lawn is riddled with chafer grubs, however, they can kill off the grass quite quickly.
When are they active?
Unfortunately, chafer grubs have a long life cycle and they could feasibly be active for much of the year. It is therefore not as simple as saying ‘look out for them in the spring’ or similar, as you can with many pests. That said, they tend to be most active from June to April so be particularly vigilant from the summer onwards.
What are the signs of an infestation?
Because the grubs live underground, you’re unlikely to see them unless you go actively looking for them. Unfortunately, the first sign you may see is the damage to the grass and by this time the infestation could be widespread. Look out for yellowing or bald patches in the grass. Chafer grubs make for a tasty meal for wildlife such as birds, hedgehogs, and even foxes and badgers, so if you see evidence that animals have been tearing up your lawn, it may be worth investigating further.
Can I check for them in the grass?
This is quite difficult due to their location underground, but you could try watering the grass and cutting a small hole into the turf. Chafer grubs love moist soil and so will sometimes make their way towards the moisture. An absence of them if you do this does not necessarily mean you don’t have them though.
How can you get rid of them?
This is where it starts getting more complex. While there are so many pest control strategies to deal with a variety of bugs and insects, there is no legal pesticide in the UK that will kill chafer bugs. There are a couple of natural remedies that are effective, but both have issues – neem oil will kill chafer bugs but it may also see off bees and ladybirds (which you don’t want). The most common solution is to use nematodes – tiny parasites that will kill chafer grubs without harming other insects or plants. The catch is that nematodes are very expensive, and treating a larger lawn could set you back a few hundred pounds. Also, as nematodes are living organisms, you can’t just store them away in case you need them again – they’ll die off.
Can they be prevented?
Yes! Prevention really is the best course of action. Not only because they’re so difficult to eradicate (see above) but because preventing them is both easy and inexpensive.
How can chafer grubs be prevented?
Iron sulphate is a really effective treatment for protecting your grass against chafer grubs. Applied to your grass (simply water in with a watering can or sprayer) it increases acidity of the soil and the grass, which chafer grubs don’t like. It also makes it healthier and hardier and more able to resist damage from any pests that do brave the more acidic soil. Note that it won’t kill any chafer grubs that are already in your grass, but it will reduce the risk of them returning next year.
Ultima Plus Iron Sulphate 2.5KG Price: £13.96
Are there any other benefits to iron sulphate?
Yes, there are several. Iron sulphate is more commonly known as a grass greener as grass that is healthy and strong will naturally be greener and more lush-looking. Using iron sulphate will not only protect your grass from chafer grubs and other bugs, but will look better, give greater coverage, and help kill moss. It will also cope better with heavy use as you spend more time in the garden over the spring and summer.
