How to Get Rid of Spittlebug UK

Someone on the allotment WhatsApp group asked me a couple of summers back whether the white frothy stuff on her lavender meant it was dying. She’d already had a go at scrubbing it off with washing up liquid before she’d even thought to ask anyone. I told her to put the kettle down and leave it alone, which wasn’t quite the answer she expected.

That frothy blob is cuckoo spit, and the insect inside it has been getting an unfairly hard time lately. Before you go reaching for anything, it’s worth knowing what you’re dealing with, because the honest answer to getting rid of it is that you mostly don’t need to.

What that froth is, and why it’s not what you think

The froth is made by a tiny nymph called a froghopper, sometimes called a spittlebug, and there are ten species of them found across the UK. The one you’ll meet most often on a lavender bush is the common meadow spittlebug, Philaenus spumarius, though some of the rarer species stick to one particular type of plant rather than feeding wherever they fancy.

It turns up in spring round about the same time the cuckoo starts calling, which is the entire reason it’s called cuckoo spit, nothing more. I used to assume there was some odd connection between the bird and the bug until someone finally explained it to me properly, and it’s a bit of a let down once you know, the timing’s coincidental and that’s it.

The way the nymph makes the foam is, frankly, a bit grim once you know it. It feeds on sap from the stem, processes what it doesn’t need, and pushes air through the excreted liquid to whip it into froth, so the little thing is sitting inside a bubble bath it’s made from its own waste. My nephew found that out on a walk with me one summer and hasn’t stopped bringing it up since, kids find that sort of fact endlessly funny.

How long it sticks around, and what it actually does to your plants

The froth shows up on young stems and leaves through late spring and into summer, busiest from around May to July. Each blob hides a creamy white nymph, no more than about 4 to 6mm long, easy to miss if you’re not looking closely. By mid to late summer those nymphs have grown into adult froghoppers, which don’t make spit at all and you’ll barely notice them, they hop away the second you get close.

I’ve never had a plant suffer from it in any way that mattered. Most of the time growth carries on completely normally. The only time it’s worth a second look is if the nymph’s been feeding right at the very tip of a shoot, which can cause a bit of distorted growth on that one stem, but that’s about the worst of it, and even that’s uncommon.

Which plants you’ll find it on

Lavender and rosemary seem to be where I see it most, my own plants get a good covering most years and have never looked any worse for it. Roses, dahlias, fuchsias, willow and chrysanthemums all turn up regularly with it too, and there’s a fair chance you’ll spot it on something else entirely depending what’s growing nearby. I’ve had a related species turn up on periwinkle as well, and that one barely seems to bother the plant at all, it just sits there doing its own thing.

The actual reason this insect’s been in the news, and what’s worth doing about it

There’s a proper reason cuckoo spit’s had a bit more attention than usual the last few years, and it’s not really about the foam at all. Froghoppers can carry a bacterial disease called Xylella fastidiosa, which causes leaf scorch, wilting and dieback, and in bad cases kills the plant outright. It’s already done real damage across southern Europe, olive trees mostly, and it’s spreading, France and Germany have both had outbreaks since it first turned up there around 2013.

The good news, and it is genuinely good news, is that Xylella hasn’t been found in the UK. Froghoppers themselves don’t tend to travel far, somewhere around 100 metres in a lifetime under normal conditions, though wind can carry them further than that. The way the disease would most likely arrive here is through an imported plant, an infected oleander or similar coming in through a garden centre or nursery, rather than the froghopper bringing it in under its own steam. Once a froghopper feeds on an infected plant though, it could pass the bacteria on to the next healthy plant it visits, which is the whole reason anyone’s paying attention to an insect that’s otherwise entirely harmless.

There’s already a fair bit standing between Xylella and a UK garden centre’s shelves. Plant importers have to show their stock’s come from areas confirmed free of the disease, anything coming in from the host species most at risk, plane, elm and oak among them, gets pre-notified to the plant health authorities before it even arrives, and there are border spot checks on top of that. Anywhere the infection’s already taken hold in southern Italy, the Apulia region specifically, has tight movement restrictions on plants leaving it. If the worst did happen and Xylella turned up here properly rather than as an isolated case, the response is genuinely severe, every possible host plant within 100 metres of the outbreak gets removed, and any garden centre or commercial grower within 10 kilometres faces serious restrictions for a full 10 years afterwards. Beyond oak and plane, the list of plants considered at risk runs to citrus, grapevine, lucerne, peach, cherry, maple and a fair few more besides, which is part of why so much effort goes into keeping it out in the first place rather than dealing with it once it’s here.

I’ve started reporting the cuckoo spit I find on my own plot to iRecord now, which takes about thirty seconds once you’ve set up an account, just your postcode and which plant you found it on. There’s a proper research project behind a lot of this work too, ten different UK research bodies led by the John Innes Centre, all trying to get ahead of exactly this kind of insect-borne threat before it becomes a real problem rather than a hypothetical one. My five minutes of reporting isn’t going to stop Xylella turning up if it’s ever going to, but it helps build a proper picture of where froghoppers actually are across the country, which matters a lot more if the disease does eventually show up here. Feels like a more useful five minutes than scrubbing foam off a lavender bush that was never in any danger to begin with.

If you still want the foam gone

I’ll be straight with you, my own advice on this one is to leave it well alone. Spittlebugs aren’t a pest, and beyond making that bit of foam, they don’t do anything worth worrying about to a healthy plant. They’re just part of the wider biodiversity any decent garden ends up supporting, one more small thing pulling its weight in a system that’s bigger than the bit of lavender it happens to be sat on. If you’ve got young children pulling faces at it or you just can’t stand the look of it on the front of the house, there’s no harm in tidying it off, you’re not going to upset anything by doing it.

A firm squirt from the hose does the job, or wipe it off by hand if you don’t mind getting a bit of insect spit on your fingers, it washes off easily enough afterwards. Don’t expect it to stay gone though, the nymph’s usually still alive and well after a hosing, just temporarily homeless, and it’ll often rebuild the foam within a day or two. I’ve gone round the same lavender bush three times in a week before giving up and just leaving it be, which in hindsight was the better plan from the start.

What you won’t need, whatever you decide to do, is a bottle of anything. No spray sold for this exists because none’s needed, and spending money trying to solve a problem that isn’t really a problem is the kind of thing I’ve done enough times with other pests to know better by now. Leave the lavender alone, let the froghoppers get on with it, and you’ll have lost precisely nothing by the time autumn comes round.