How to Flush out Garden Pests in Winter

, written by Benedict Vanheems gb flag

Icy apple tree branches

Winter – and I mean a decent, cold winter with multiple frosts – can be actually be a boon to the gardener. The trick is to tame the cold and turn it to your advantage. One way to do this is to use it to flush out lurking insect pests. Expose them to the frosts, as well as a legion of hungry birds, and they’ll have no chance! The combination of piercing cold and probing beaks will put a big dent in pest numbers, giving your plot a head start come spring.

Expose Grubs to Frost

One of the very simplest ways to quash overwintering bugs is to work out where they’re hiding and bring them to the surface. The best way to do this at ground level, particularly around fruit trees and bushes, is to rake up and remove fallen leaves, before turning over the top few inches (5-10cm or so) of soil. Even simply tickling the soil surface with a border fork to ruffle up the leaf litter can bring hibernating grubs to the surface. In their state of torpor, they won’t be going anywhere and the icy grasp of frosty nights can be left to do its work.

Forking soil

Where thick mulches cloak the ground around winter crops, start by peeling the mulch back. Rake it away during the coldest weeks of the year to allow the frost to penetrate the ground and cleanse the soil. Of course, you will probably want to keep some crops (for example parsnips and carrots) covered to facilitate lifting them out of the ground during iron-cold weather.

There’s a balance to be found here – between slowly feeding the soil over the quieter months, and giving it a frosty ‘deep clean’ in time for the new growing season. A good compromise is to expose soil for three or four weeks over the coldest time of the year before covering it back over with mulch.

Raking back mulch

The Role of Birds in Pest Control

Tickling, turning and uncovering the soil also yields a veritable feast for insectivorous birds. In the deep of winter, when the ground is hard and there’s little wild food, a bonanza of newly exposed fleshy grubs and bugs will help our feathered friends through a very hard time.

Additional feeding of birds will help keep them on side. Far from detracting their attentions from natural pest control, a well-stocked bird feeding station will draw in more wild visitors, making your garden a local hub. More birds in your garden mean more eyes and more beaks, which can only be a good thing for pest-weary gardeners!

Bird foraging in grass below fruit trees

Fruit cages are invaluable at protecting fruit bushes and small fruit trees from birds during the growing season. Winter is a good time to temporarily remove the netting to allow birds free access to the invertebrate snack bar. If you have chickens you can also allow them access. Their inquisitive beaks will turn over the soil surface to ruthlessly flush out and devour the lurking pests beneath.

One word of caution is required when removing netting from fruit cages. Sometimes birds such as bullfinches and tits will feed on young fruit buds, causing severe damage that necessitates pruning in order to encourage replacement shoots. So clearly a degree of monitoring is required, with netting replaced as soon as any damage is suspected.

Flush Out Pests With a Winter Wash

Winter washes are another weapon in the gardener’s fight against insect pests. A winter wash is a fish or plant oil-based solution that’s sprayed all over the exposed branches of fruit trees and bushes. The object? To kill overwintering pests, either on contact or through smothering and suffocation. Winter washes are effective against many types of mite and sap-sucking aphids. By controlling these insects the incidence of viruses is also greatly reduced – a double win!

Spraying an apple tree with a winter wash

Winter washes are sprayed on, often using a pump-up pressure sprayer, so you’ll need to wait for a completely calm day before applying it (you don’t want clouds of it to simply blow away). Try to get the best coverage you can, spraying the wash into every nook and cranny. Smaller trees and shrubs are the easiest to cover, for obvious reasons. Larger trees can be tricky, but concentrating on those areas you are able to reach will still make inroads on pest numbers.

Clear Away Weeds

Weeds are another hideout for overwintering pests. It’s good practice to remove weeds from your winter vegetable plot and from around fruit trees so that frost and prying beaks can get in and do their work.

Weeding a vegetable bed

Don’t be too thorough, though. Many seedlings of biennial flowering plants such as calendula should be left to provide essential flowers to entice next season’s beneficial bugs – the predators that will keep common pests in check once warmer weather returns. The same goes for ladybug and lacewing-friendly plants such as nettles. Concentrate on removing seedlings you know to be annual weeds, as well as maintaining your assault on pernicious perennial weeds such as bindweed and ground elder.

Removing habitats for overwintering pests, while at the same time actively going after them is a great way to wipe the slate clean for the new growing season. As you go about your pest purge, please remember to let us know what you find. You can report any bugs you see – including beneficial ones – at the Big Bug Hunt website. In doing so you will be part of a major citizen science project that we’re coordinating. Its aim is to eventually develop an early warning system against pests, so a small investment of time on your part could yield a massive impact on how we all deal with garden pests.

Bugs, Beneficial Insects and Plant Diseases

< All Guides

Garden Planning Apps

If you need help designing your vegetable garden, try our Vegetable Garden Planner.
Garden Planning Apps and Software

Vegetable Garden Pest Warnings

Want to Receive Alerts When Pests are Heading Your Way?

If you've seen any pests or beneficial insects in your garden in the past few days please report them to The Big Bug Hunt and help create a warning system to alert you when bugs are heading your way.

Show Comments


"Have you a recipe for a home-made winter wash? I've been using Volk Oil spray on my fruit trees, once a winter, during a day when temps are above freezing, but it's so expensive and kind of hard to find where I live."
Ilene on Friday 16 December 2016
"Hi Ilene. It can be expensive. I haven't used a home-made winter wash myself. This article here - - has some good advice on making your own winter wash (they call it dormant oil). Believe it or not, I've also heard of urine being used (somewhat diluted) as an effective winter wash. I can't vouch for this, but it may be worth some investigation."
Ben Vanheems on Friday 16 December 2016
"I'm in southern Californa, but appreciate this information. Also enjoy your great style of writing!"
Sharon on Friday 16 December 2016
"Many thanks Sharon, that's very much appreciated. Hopefully there will still be a few tips in there for you too."
Ben Vanheems on Friday 16 December 2016
"During the growing season I tried several times to report bugs in my garden but I could not get the site to accept my comments."
John D Kelly on Monday 9 January 2017
"Hi John. Were you using this site - - or our bug reporting site - ? I'll get this looked into. Many thanks for letting us know."
Ben Vanheems on Monday 9 January 2017
"I was trying to use the "bigbughunt" site not the "growveg" site to report bugs in my garden this past summer. I was not aware of the "" site."
John D Kelly on Monday 9 January 2017
"John - the Big Bug Hunt is being continuously updated, so it's quite possible that the problem you experienced has already been fixed. If you have any difficulty reporting bugs, please just use the Contact Us link, either on the Big Bug Hunt website or on giving details of what you see on screen and we'll be happy to assist further. Thanks for contributing to the project!"
Jeremy Dore on Tuesday 10 January 2017
"Turning the soil to expose bugs sounds good but how do you do that when the ground is frozen solid?"
Sandra on Tuesday 24 January 2017
"I've recently read articles about keeping the garden 'messy' over the winter (not cleaning up fallen leaves and not cutting old canes from perennials) and not digging the garden as a way to protect overwintering beneficial insects and amphibians. Then I read articles like this one that discuss clearing leaves and digging the garden as a way to get rid of pests. I'm confused! Is there an article that can make sense of this seemingly contradictory advice? "
Sandy on Tuesday 24 January 2017
"Hi Sandra. You can't! You'll have to wait until the ground is thawed to avoid damaging the soil structure. But if you're getting a good, cold winter, then that will be doing a lot of the pest-cleansing work for you already."
Ben Vanheems on Wednesday 25 January 2017
"Hi Sandy. There is a lot of contradictory advice. My strategy would be to clear material from around fruit trees and bushes, but keep areas to the edge of the kitchen garden 'messy', as these will be great banks for beneficials. But do your best to weed around perennial fruiting plants at the very least."
Ben Vanheems on Wednesday 25 January 2017
"Can I use this method ( dig up beds during winter) to control pepper fly maggot which pupuates in the soil over winter? I am in southern ontario canada where we get pretty good winters. so if i dig up the beds a few times the pupuas will die? how effective is this method? have you ever heard of using it for this spcific pest?"
clara on Monday 23 August 2021
"Hi Clara. I haven't heard of this method used for that specific pest. However, by repeatedly bringing the pupae to the surface through digging, there's a much higher chance of them perishing from extreme cold or predation, so I'd suggest it's a good idea."
Ben Vanheems on Tuesday 24 August 2021

Add a Comment

Add your own thoughts on the subject of this article:
(If you have difficulty using this form, please use our Contact Form to send us your comment, along with the title of this article.)

(We won't display this on the website or use it for marketing)


(Please enter the code above to help prevent spam on this article)

By clicking 'Add Comment' you agree to our Terms and Conditions