Plants are often collected due to unique features, and the genus Calathea is a perfect example.
While these plants are relatively easy to care for, you can’t always keep your Calathea plant pest-free. Among the most common issue you will face – Calathea spider mites.
The foliage of many Calatheas is unique, like Calathea Roseopicta and Calathea Warscewiczii. All 60 or so species are commonly referred to as prayer plants, due to a curious mechanism that causes their leaves to fold upwards in a prayer pose at night.
While we don’t fully understand why this mechanism exists, it’s made Calatheas some of the most popular indoor plants among home gardeners.
How To Get Rid Of Spider Mites On Calathea Plants
Having an infestation of spider mites doesn’t mean you’re a bad plant parent, but it can pose a potentially serious risk to your Calathea and other nearby plants.
Here’s what you need to know about the signs, risks, and treatments available for this common pest.
Signs Of Spider Mites And Spider Mite Damage
Spider mites are quite tiny (around 1/16″ inches long), and there are over 1,200 different species.
However, the most common one in gardens is the red spider mite (Tetranychus urticae, also often called the two-spotted spider mite).
If you look closely at your plant, you may see these tiny pests milling about, but this isn’t always a reliable method to search for them, as they prefer to hide on the undersides of leaves.
Instead, one needs to look no further than the messy, silky webbing they use as bridges between leaves.
The damage is another possible indicator of a spider mite infestation.
These pests are of the piercing type, meaning they use their mouthparts to pierce a single leaf and drink the sap.
Eventually, the infected plant leaves may begin to show spots where chlorophyll is missing or where the damage is killing that portion of the leaf.
Left untreated, the infected plant will become prone to disease, especially fungal infections, and may even die.
But that’s not the worst part.
Spider mites thrive in dry conditions and have life cycles lasting only a month, yet a single adult female can lay as many as 400 eggs in her lifetime.
When a plant becomes too crowded, the spider mites can use their silken threads as parachutes, scattering throughout a room or your outdoor plants on the tiniest breezes.
There are several chemical pesticides available for fighting spider mites.
However, it’s important to remember these are a type of arachnid, so not every product designed for insects will work on them.
Pay attention to any instructions on the label, as different products may have different side effects, dosages, and application rules.
Natural pest control doesn’t get much better than calling in Nature’s own cavalry.
Several predatory insects see spider mites as a tasty treat, from ladybugs to some species of predatory mites.
These guys won’t just devour spider mite eggs. They also consume a variety of adult pests, such as scale insects, aphids, and thrips.
Of course, you probably don’t want to invite these little insects and arachnids into your home, but having some beneficial insects in your garden can help prevent and control spider mite infestations.
Perhaps the best way to combat spider mites is through natural remedies.
For example, when you wipe down your plant’s foliage, add insecticidal soap or a neem leaf shine to a damp cloth.
You can also use a bit of isopropyl alcohol, which will kill the mites on contact.
Just be sure to use a soft cloth, such as a microfiber or paper towel, to avoid damaging the leaves.
Neem oil is perhaps the best medicine, however.
As mentioned, a Neem leaf shine can kill spider mites on contact.
Similarly, a neem foliar spray will kill on contact and dissipate in under an hour, leaving no residue that could harm beneficial insects.
Just be sure to apply neem oil products when garden helpers and pollinators are away at dusk or dawn.
However, a neem soil soak is perhaps the best use of neem oil.
While a foliar spray is applied every other day, a soil soak is applied once every 3 weeks, poses no harm to beneficial insects or earthworms, and functions as a systemic treatment method.
To make the soil soak, you will first need to emulsify some water.
Begin by adding 1 teaspoon of Dawn dish soap or pure castile soap to a quart of water (this same amount will also work with a gallon of water).
It’s best to use lukewarm water near or at room temperature, as neem oil is sensitive to heat, and cold water may shock your plant.
Also, avoid tap water and aim for either distilled or natural rainwater.
Now that you have an emulsified water solution mixing in oil is possible.
Blend 1 teaspoon of 100% percent cold-pressed raw neem oil per quart (or 2 tablespoons per gallon) into the emulsion and pour 2 to 3 cups of this mixture onto the soil around your plant instead of watering it.
Be sure to avoid getting any on the plant itself, as neem oil can be very potent and may cause burns to sensitive plants.
The roots will absorb the neem oil, remaining in the plant for up to 22 days, killing piercing or chewing insects.
Neem oil has a relatively short lifespan once blended, so try only to make as much as you need and never store it in direct sunlight.
While neem oil can be used as a preventative and a treatment, you can do some basic things in your regular care regimen to help prevent a spider mite infestation.
For example, try to ensure your Calathea has the proper humidity levels.
High humidity may lead to fungus gnats and fungal infections, while low humidity can invite spider mites.
Also, practice good watering techniques, such as the soak and dry methods.
While simple, this method can prevent you from underwatering or overwatering your plant, attracting all sorts of pests, or even leading to root rot.
Finally, ensure the plant is getting the right amount of bright, indirect light, as spider mites aren’t keen on being exposed to bright light, and poor lighting may leave your plant more vulnerable to problems.