An inevitable part of every gardener’s life is dealing with pests. Those of us enamoured with succulents are more fortunate than most – we have fewer bugs trying to munch our plants. Still, audacious insects attempt it occasionally, so you should be prepared to defend yourself and your plants.
The first (and most important) step to treating any pest is to quarantine affected plants. Infestations will usually take several days to a week to treat, and you need to ensure that the pest isn’t able to spread to unaffected plants.
A successful quarantine relies on you catching the pest early. I probably don’t need to tell you to do regular inspections because you’re already looking at your plants every day. If you’re not, for some strange reason, make an effort to look carefully at every plant in your collection at least once a week. Check under leaves and in nooks and crannies. Pests like dark, damp places.
If you find something suspect, quarantine immediately. Take the plant into another room, if possible, or at least 2 meters away from the others. Then, begin treatment.
Perhaps the most common succulent pest and, fortunately, one of the easiest to treat. They are easy to identify too: specks of white cottony material about 1-2 mm in length. They tend to group in crevices; often where the leaf meets the stem.
You can treat these by washing them off with a particularly powerful stream of water. Some succulents drop leaves at the slightest touch, however, so this approach won’t work for them.
Instead, try spraying a 70% isopropyl alcohol solution on the affected areas. It won’t harm your plant. A neem oil solution is also very effective in treating mealybugs.
There is a much more detailed explanation of mealybugs, their prevention and their treatment, over at Sublime Succulents if you want to check it out!
While most pests are soft-bodied insects like mealybugs or aphids, scale is a hard-bodied bug. What this means for you is that treatment is more difficult.
They usually appear as brown to black colored bumps that are oval in shape. Scale hugs the plant very tightly, and won’t be removed by simple brushing or water. You can try the alcohol solution detailed above, but chances are it will take several treatments to get some results.
While I generally try to avoid using insecticides because of the collateral damage it can cause to beneficial insects, a scale infestation means you have to get serious. Try an insecticidal soap or neem oil solution. Don’t apply them during the day, or the oils that linger on your plant could cause it to burn.
Also called sciarid flies, these pests look (and act) a lot like fruit flies. Also like fruit flies, they’re not very harmful to your plants – they’re just annoying.
These gnats pop up when your soil stays wet for too long. They lay eggs in the dirt, then the larva munches on dead and decaying matter. Those baby fungus gnat require moisture to survive, so they’ll go away if you adjust watering frequency accordingly.
I’ve got rid of them several times by simply inflicting a drought – I delay watering until I don’t see the flies anymore. The adults only live for 10 days or so, and the eggs and larvae wither if they’re not moist. A more immediate solution is to mix some hydrogen peroxide into your water the next time – that’ll get them too.
To prevent them from appearing at all, make sure you only water when the soil is totally dry – then wait another day or two. Top-dressing like a layer of gravel on top of your soil can also help dissuade the flies from making your plant their home.
Remember, Prevention is the Best Treatment
Most of these pests can be avoided by simply having good garden hygiene. Don’t let your plants or their soil stay wet for too long. Make sure there is plenty of airflow of dry air. Prune occasionally, and remove dead plant matter from pots.
A pest invasion isn’t a reason for panic. By catching it early you can mitigate the damage done. Many infestations will require treatment to be repeated every few days until the pest goes away.
Even if a plant is severely affected – it’s ok! These are succulents we’re talking about. Just propagate it.
About the Author
Patrick Grubbs runs the website Sublime Succulents – a site dedicated to saving succy lives through education. When he’s not writing tutorials about pest control, he’s figuring out how to fit more plants on his windowsills.