A Bad Case of Scale on the Monstera – and why Dollar Stores are great gardening resources


I have a split-leaved “Monstera” Philodendron, those shapley 50s style climbers that have such an architectural presence. They’re beautiful house plants. The leaves, when mature, are quite thick and leathery – just the kind of plant, for some reason, that scale insects love. Here’s a photo of a Monstera.

These armour covered insects are very hard to eradicate because they hold on to the plant surface for dear life. Their tough casings seem to protect them from the usual organic bug spraying techniques. The only way to get rid of them is to scrape them off the surface with something hard.
It’s got to be hard enough to scrape off the scale, but soft enough that you don’t injure the plant tissue. I used to do this with a fingernail and a waiting damp paper towel. A very painstaking process. I’ve spent hours of my life doing this, while thinking: “Why don’t I just toss this plant? Why am I spending half my life doing this?” Then usually answering, “I can’t help it! I must help this plant! It didn’t ask to have scale!” So. A problem to be solved. Some info about scale I gleaned from my research here.

Soft Brown Scale Insects are a bit like minature turtles in shape. The older females are dark brown and are usually found along the centre vein on the under side of a leaf where they suck the sap. They excrete ‘honeydew’ which is full of sugars and drops onto the lower leaves or anything below. You may find nymphs, known as crawlers as they are able to move around. the older females lose their mobility and eventually die, but their shell remains to protect the eggs.

The eggs hatch into first stage nymphs, or crawlers, when they are laid. These move out to find feeding sites within a few days. After about a week, they molt into the second stage, a passive nymph. Adult males and females emerge in about a month. The males have wings and are rarely seen. There can be up to six or seven generations a year indoors, so a colony can rapidly grow.

I’ve never actually seen a “crawler” and I’m glad I haven’t. They must move around pretty sneakily. But the brown bumps are obvious. I suppose the best way to eradicate them is a regimen of scraping and spraying with insecticidal soap to target the movable (and seemingly invisible) crawlers.

As far as scraping methods go, I became quite excited this fall when I came up with the idea of using a common bath “scrubbie” to dislodge these creepy creatures in one fell swoop. I mixed up some insecticidal soap and went at it. See picture below. This worked quite well, but a couple of weeks later I noticed many had returned. Damn them!

Luckily I had just purchased at a dollar store a microfibre cloth that had a soft surface on one side and a scrubbier surface on the other. The scrubby side had an extra weave of polyester fibres that stuck out in a very short nub. Perfect for the scale. I used just plain water this time, and flattening each leaf out on my hand I swept over each leaf with the scrubby side. The cloth is easy to wrap around the stems as well, where some of them hide.

Perfect! Now my plant is scale-free once more. So get yourself down to the dollar store and search out a microfibre cloth with a “gentle scrubbing side” just to add to your gardening intensive care arsenal. And if you don’t ever get scale, they work great on teflon!

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