Spider mites are a winter houseplant epidemic in Canada thanks to the drier household air of the season. The mites thrive in warm, dry places and seem to appear out of nowhere when we turn our furnaces on for another Powell River winter.
Cousins of the arachnid family, spider mites are smaller than the period at the end of a sentence. Indoors, they’re happy to infest any houseplant, and they will do serious damage if left alone. The good news is that, with persistence, spider mites are relatively easy to control.
Spider Mite Life Cycle
Spider Mites reproduce crazy fast. Once females reach maturity, which happens in as little as five days, they mate and then start producing eggs. These randy little bugs can lay up to three hundred eggs over a couple of weeks, so you can imagine how they can very quickly get out of control. At the first sign of an infestation, it’s essential to deal with them immediately.
Spider Mite Damage
Sometimes called vampire mites, they puncture tiny holes in the undersides of leaves and suck out the liquid. The damage will first appear as tiny yellow or dry-looking brown spots.
If you turn over the leaf, you’ll see the tiny mites bustling about. If you take out a magnifying glass, you should be able to see their eggs scattered about the underside of the leaf.
If you’ve got webbing around leaves and stems, rusty-red spots on foliage, and hundreds of speck-like creatures scurrying around on the plant, you’ve got an extensive infestation. Isolate your plant immediately and inspect others for signs of mites.
Tackling Spider Mites
Outdoors, spiders mites have plenty of natural predators, like ladybugs, lacewings, and predatory mites. In the house, there are not too many predators. They are generally resistant to conventional pesticides, so don’t just start spraying them with whatever you’ve got kicking around. Here’s what you should do:
Isolate the infested plant as quickly as possible to keep them away from other plants. Spider mites can ride drafts or wind with their tiny webs. Carefully check surrounding plants for infestation. It’s probably a good idea to treat nearby plants even if you don’t see evidence yet—just in case. If the plant is severely infested, it may be best to discard the entire plant and its soil. Make sure to dispose of it in a yard waste bag and get it off your property as quickly as possible. Do not compost the plants.
There are two ways to use water to tackle spider mites. First, keep your plants well-watered for their individual needs. Hot and dry conditions are what appeal to spider mites, and plants that are stressed from lack of water are more susceptible to infestation.
Second, a good old squirt bottle is effective at removing them. Giving the underside of leaves a vigorous rinse with the ‘jet’ setting of a squirt bottle will remove most of the mites. If you’ve got bigger plants, you can also take them in the shower or the sink and use the sprayer on the underside of the leaf. Make sure you get into the crooks and crannies of each leaf and stem. You may need to repeat your spraying routine every day or two to deal with the infestation.
3. Clean & Damp
Keeping your houseplants leaves clean, regularly wiping them with a damp cloth, and periodically misting them will help dissuade mites. However, if the bugs manage to find their way into your home, these measures won’t entirely prevent an outbreak.
4. Insecticidal Soap
Insecticidal soap can help if you have a significant infestation. Because these little creatures reproduce so quickly, they can quickly adapt immunity to chemicals. If you’re going to use insecticidal soap, its important to repeat treatment every 2-4 days for a few weeks to make sure you’re catching newly hatched mites. Insecticidal soap works by clogging the insects’ breathing organs and suffocating them.
5. Beneficial Insects
Ladybugs, lacewings, predatory thrips, or predatory mites can be an effective treatment if you can release them early into an infestation. Ladybug larvae are even more voracious than the adults. These polka-dotted bugs look cute, but they’re a powerful, natural defense against mites!
6. Healthy Plants
The best way to keep spider mites at bay is to keep your plants healthy and inspect them regularly. It’s a good idea to isolate plants that start to look sick until they’ve recovered.
The most effective plan for spider mites is vigilance and persistent treatment. The earlier you catch them, the better. As we’re heading into fall here in Powell River, keep a keen eye on your houseplants. Have a squirt bottle handy, and regularly inspect your plants for signs of insect attacks.
If you’ve got an infestation on your hands that is beyond what a squirt bottle and quarantine can solve, come by our garden centre. We can set you up with a mite-control plan and the products you need to tackle these nasty critters.