Aphids on smartweed - to chop and drop or not?

Hi, this is my first post! So I started chopping and dropping in my garden, but as I was going along I noticed most of the smartweed has aphids on it. I also noticed some ladybugs hanging around most likely having a feast. I decided to toss the smartweed I chopped into the woods and left most of it growing in the ground since none of my plants seem to have had any issue for the past few weeks.

BUT, I don't know what to do. Should I leave the smartweed to deter aphids from going after my plants or can I still chop and drop? Will aphids in the ground begin to spread? Not sure if anyone has experienced this but every smartweed plant basically has aphids. I planted a bunch of beneficial pollinator plants and flowers but they have yet to come up. I'm not too worried since none of my plants are bothered, but wondering what to do moving forward. Thanks so much!!

Hi Kelsey,

Welcome to Permies.

Welcome to the forum!

do you see ants?  Get rid of the ants and get rid of the aphids.  Vinegar is your friend.

I live in Washington state, and I use Neem oil for Aphids on my wife's rose plants, as far as I can see it's about the only thing Neem oil works for, but it works great for the Aphids, hope this helps.
Good luck.

I think I would leave them.
You would be providing for the beneficial insects and as you said, your plants seem fine.

William Bronson wrote: I think I would leave them.
You would be providing for the beneficial insects and as you said, your plants seem fine.

That is what I have been doing! Thanks

Hmm, i'm certainly no expert on this topic so take my advice with a heap of salt.

In my observation, I've seen trees totally covered in aphids next to trees of the same species without a single afid on them. Likewise i've seen branches covered in aphids with all other branches untouched.

I do know that plants are able to make a metabolite that can kill off aphids by stopping their digestion, aphids are unable to attack plants that are sufficiently healthy and can afford to create these chemicals. There's a reason aphids don't just wipe out every crop, other than predators. Plants have many biological mechanisms of self defense, some include attracting predators but most include complex biological defenses.

I read about the digestion metabolite long ago but can't find the source anymore.


https://www.nature.com/articles/s41598-018-34821-w
https://www.mdpi.com/2223-7747/13/16/2332

You can read the abstracts above for some other mechanisms, the point is plants have defenses against aphids. Typically the plants that are covered in aphids are the ones that are the least healthy because they either can't spend the energy to create these expensive metabolites or can't get the correct nutrition.

If all of your plants are unhealthy, then you may have to worry about aphids spreading. If only a couple are unhealthy or only these smartweeds are, then the aphids aren't a big deal and attracting some of their predators might actually be beneficial.