Aphids On Pothos: How To Deal With Them

Good news: aphids are the least of your Pothos worries.

Thrips will hunt this plant down. Mealybugs will take it if nothing better is going. Aphids, on the other hand, would really rather be somewhere else, and if you keep your Pothos indoors you may never meet them at all.

The catch is that aphids are trivially easy to deal with in the first week and a proper nuisance by the third, and the gap between those two states is much shorter than people expect. So this is a short article about acting fast.

What aphids look like

Small, soft, pear-shaped insects, one to three millimetres long, clustered together on the newest growth and the tips of stems.

Usually green, hence greenfly, but they also come in black, pink, yellow and a sort of dusty white.

The reliable identifier is a pair of tiny tubes sticking out of the back end, like exhaust pipes. Nothing else in this silo has them. If you can see those, it’s an aphid.

Some have wings and some don’t. Aphids grow wings when things get crowded or the plant starts running out of what they want. So winged aphids mean the colony has decided to expand, and other plants in the room are about to be visited.

Why they’d rather eat almost anything else

Aphids like soft, sappy, tender plants. Ferns are aphid magnets. Herbs are aphid magnets. A Pothos leaf, by comparison, has the texture of a shopping bag.

My own theory is that the calcium oxalate crystals in Pothos leaves are part of it. They’re the reason Pothos is mildly toxic to pets, and the reason a cat that chews one gets mouth pain and drooling rather than anything serious. It would be neat if the same defence kept insects off.

In the interests of not overselling it: I don’t think that’s proven, and there’s a decent argument against it. Aphids don’t chew. They thread a needle-thin mouthpart between the cells and drink straight from the plant’s plumbing, which may well take them past the crystals entirely. Chewing pests get shredded by that defence. Sap-suckers arguably sail through it.

Which means the boring explanation might be the right one: a Pothos leaf is thick, waxy and tough, and there’s a fern two rooms away having a much easier time of it.

Either way the practical conclusion holds. Aphids are not a Pothos specialist, and if they turn up you have usually done something to invite them.

Outdoors changes everything

The thing you can do to invite them is put the plant outside.

Aphids live out there in numbers that don’t bear thinking about, and a plant on a patio is a plant advertising itself. I put a schefflera outside one summer and it could not shake the aphid larvae for the rest of the season, which was particularly annoying because a schefflera has none of the defences a Pothos has. It was the softest thing in the garden and they knew it.

If your Pothos summers outdoors, aphids move from unlikely to likely. That’s the trade you’re making.

Common Pothos Pests: How To Identify and Destroy Them

Signs you’ve got them

• Visible clusters on new growth and stem tips. Aphids don’t hide the way thrips do, which is the one truly kind thing about them.
• Sticky leaves. Aphids drink sap, which is mostly sugar, and what comes out the other end lands on everything below. If your Pothos is inexplicably tacky, that’s honeydew.
• Black film on the leaves. Sooty mould growing on the honeydew. It looks like the plant is rotting and it isn’t, it’s living on the sugar, but it does block light so it’s worth wiping off.
• Curled, puckered new growth. Aphids feeding on a leaf before it’s finished unfurling distorts how it opens.

Mealybugs On Pothos: The Complete Guide

Why Are My Pothos Leaves Curling?

Why they explode so fast

Here’s the fact that explains your entire experience of aphids.

Aphids don’t bother with males for most of the year. Females produce live young without mating, and those young are already carrying the next generation when they’re born. Generations are stacked inside each other like a set of Russian dolls.

That’s why a plant with six aphids on Monday has two hundred on Sunday, and it’s why the first week is easy and the third is miserable. You aren’t fighting the aphids you can see. You’re fighting the ones already inside them.

Act early. You have been warned.

The sacrificial plant

This is the trick I’d actually recommend.

Give the aphids something they want more.

I keep a parsley plant outside and the aphids adore it.

It is, without exaggeration, the most effective aphid control I have. They pile onto the parsley and leave everything else alone, and because they’re all in one place I can see the problem instead of hunting for it.

My boyfriend snips the tops off where the larvae are gathered and drops them into his fish tank, where the fish treat it as a delivery service.

The principle is the same one that keeps mealybugs off my Pothos: pests go to their favourite host first. If you know what that host is and you have one, it works as both a decoy and an early warning system.

Parsley, nasturtiums and broad beans are all reliable aphid magnets.

You are not aiming for a garden with no aphids in it. That garden doesn’t exist (also, the birds love ’em). You’re aiming for a garden where the aphids have somewhere better to be.

Ants are the complication

If you see a line of ants marching up your plant, follow them, because they’re almost certainly farming.

Ants harvest honeydew from aphids and defend them for it. They’ll fight off ladybirds, move aphids to better feeding spots, and generally behave like a private security firm. An aphid colony under ant protection is much harder to shift, and the ants are often the first thing you notice.

Dealing with the ants doesn’t remove the aphids, but it does mean everything else you try has a chance of working, and it means the local predators can get in.

Let the ladybirds do it

Outdoors, you have help. Ladybirds and their larvae eat aphids in impressive quantities, as do lacewing larvae, hoverfly larvae and several parasitic wasps.

Ladybird larvae look nothing like ladybirds, which is why so many people squash them. They’re small, elongated, dark grey or black with orange markings, and vaguely alligator-shaped. If you find one on an aphid-covered plant, leave it be. It’ll eat several hundred aphids before it grows up.

This is the argument against spraying anything broad-spectrum outdoors: you kill the aphids and their predators together, and the aphids come back faster because they breed faster. You end up with a garden that needs you.

How to get rid of them

Squash them. For a small cluster on one stem, run your fingers up it. Unpleasant, immediate, free.

Hose them off. Aphids have a weak grip and blunt little legs, and knocked-off aphids largely don’t find their way back. Take the plant to the sink and blast it, undersides included. Repeat weekly.

Soap or oil if it’s spread. Insecticidal soap or neem oil, which kill by suffocation. A drop in a one litre spray bottle. Evening application, since both make leaves prone to scorching in strong light.

Cut off the worst bits. Aphids concentrate on the newest, softest growth. Removing the two or three tips they’ve colonised often removes most of the population in one snip.

Repeat whichever you pick for a few weeks. Given how they reproduce, one round of anything is a delay rather than a solution.

When to chop

Rarely necessary with aphids, since they sit out in the open where you can reach them. But if a plant that summered outside has come back covered and you can’t face the weekly routine, cut it back to the soil. Pothos regrow from the base quickly and you lose nothing but time.

How To Propagate Pothos: Every Method Explained

Prevention

Check new growth when you water. Aphids go for the tips, so that’s a five-second inspection.

Quarantine new plants for a couple of weeks before they join everything else.

Inspect anything that’s been outside before it comes back in, tips and undersides especially.

Keep the plant healthy. A stressed plant releases hormones that make it a more appealing target, so light and watering are doing pest control work whether you think of them that way or not.

Frequently asked questions