Plum Tree Aphid Infestation
Let’s chat about my poor plum tree.
I grow and farm with a permaculture mindset—working with nature as much as possible and avoiding sprays and chemicals. The trade-off is that solutions often take longer, and there aren’t many quick fixes.
Which brings me to the aphid infestation.
In early spring, I noticed my Pipestone Plum was completely taken over by aphids. The good news was that nature’s pest control team was already on the job: ladybugs, Asian lady beetles, and soldier beetles were all present. So my initial strategy was to let them do what they do best.
To give them a head start, I removed and destroyed as many infested leaves as I could. It helped for a while. Over the following weeks, even more ladybugs arrived, laid eggs, and their larvae got to work—each one can eat roughly 400 aphids as it grows.
But unfortunately, it didn’t last. The aphids surged again and took over.
How to tell it’s aphids (and not something like leaf curl)
Aphids can look similar to certain leaf issues, but a few signs make it clear:
Lots of ladybugs and other predatory insects on the tree (ladybugs’ favorite food is aphids).
Lots of ants—ants have a symbiotic relationship with aphids. They “milk” the honeydew (sugary droplets) aphids produce and, in return, protect them from predators.
When you uncurl the leaves, you’ll often find small green bugs, eggs, or shed skins (molts).
At this point, the aphid pressure is high enough that it’s starting to harm the tree. Since it’s a few years old, it should survive this season—but it’s showing weakness and damage. If I let this repeat next year, it may not make it. So it’s time to pivot.
What I’m not doing
Right now, I don’t want to use insecticidal soap or other sprays. They don’t just kill aphids—they can also harm the beneficial insects in and around the tree, and I’m not willing to wipe out the helpers. Instead, my first step is going to be trialing a very mild soap and oil treatment. This consists of 1/4 of a teaspoon of vegetable oil, 1/8th a teaspoon of mild soap mixed into 1 liter of water, then sprayed on the plant. This in theory should hinder the aphids without harming the beneficial insects. Hopefully giving them the upper hand.
My next pivot: Strengthen the tree
Then, I’m focusing on natural fertilizers and foliar boosters for both the canopy and the root system. The idea is simple: nourish the tree so it can recover from the damage—and because healthier trees are better able to defend themselves against pests and disease.
By feeding the roots and spraying the underside of the leaves, I’m aiming to build resilience from the ground up.
The mix I’m planning to try is:
compost tea
liquid kelp
sea minerals
liquid fish
I may adjust once the compost tea is finished, but that’s the plan for now. My hope is that this works well enough that I won’t need to turn to neem oil or insecticidal soap.
Then, during dormancy, I’ll apply a dormant spray. Dormant sprays are organic, and they work by smothering overwintering insects and eggs so they can’t hatch in spring.
A few lessons learned
Pipestone Plum is delicious—but it’s bred more for taste than hardiness. Trees like this often need more attention than tougher prune plum varieties.
Dormant sprays may be part of my future. I need to do more research and choose one I feel comfortable using.
I still have soil work to do. I’ll be amending throughout the season, because weaker, more susceptible trees often start with what’s happening underground.
Overall, this has been a great learning experience—and it’s exactly why I started with a small, four-tree food forest in the upper yard before planting a larger orchard out back. This setup gives me experience and practice on a smaller scale, and I’m genuinely grateful for what it’s teaching me.
Now it’s time for more research and learning—which I’m excited (and thankful) to be able to do.
Until next time, happy gardening,
The Chronically Tired Gardener
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