Calathea is a beautiful, waxy plant from the tropics of South and Central America. Its bold colors and large leaves make it a perfect part of the canvas that is your garden.
What makes it even more beautiful is that it folds during the night and unfurls during the morning, making it feel like a dear friend greeting you rather than a plant in your garden.
However, if you find webbing on your Calathea or see tiny spider-like creatures crawling all over it, then there is a problem. Spider mites.
These little bugs are not here to admire your plant’s beauty, but to desecrate it and leave you with nothing but some dead stalks and an empty pot.
So, what can you do? Should you fight back against these little invaders? Or just let the plant die?
Today, we are going to give you some tips and tricks for identifying, controlling, and preventing spider mites from ruining your Calatheas.
Spider Mites: Everything You Need To Know
These little beasties are mites but not really spiders, instead they are cousins of the same family group, the Arachnids.
They are truly tiny as well, being significantly smaller than a lot of their relatives at about 0.04 inches or 1 mm in size, with some species being even smaller at about 0.51 mm – about the size of a dot on a page made with a ballpoint pen.
While these arachnids range in color, they tend to stay around a white or reddish-brown, which makes them very easy to spot on plants, especially considering that they are so small.
The one issue with this is that they can blend in with the underside of some leaves that have a purplish color, but if you take a minute, you should find them no problem.
If you do happen to see a spider mite, then assume there are not only far more, but that they have already laid eggs. These eggs are practically invisible to the human egg, because they are so small.
Not only that, but females can lay up to 20 eggs a day which hatch within 3 days, meaning that as soon as you see one mite, you must take action.
Why Are Spider Mites A Problem For Calathea?
The reason that spider mites are a problem for Calathea – and indeed most plants – is due to what the plants represent to them: food.
See, spider mites feed on plants, much like other tiny arthropods and mollusks, however the way they feed is more damaging than just eating the leaves.
Spider mites use a proboscis-like appendage to pierce the body of the plant and suck the juices flowing within.
When one or two creatures do this, it isn’t so bad – think of it like a mosquito bite – but when thousands of tiny creatures are doing this day by day, the plant will not get any food for itself and begin to die.
The Life Of A Spider Mite
Spider mites tend to live for between 2 and 4 weeks and go through a few stages of life during that time. First, they are laid by a female on an appropriate leave and after 3 to 5 days they hatch into a larva.
This larva will feed on the plant sap, before heading to the underside of a leaf and molting into a nymph form, which is slightly larger and a different color.
They will feed again and molt again, becoming a deutonymph, before repeating the cycle one last time and becoming an adult.
This change happens fast, normally within 5 days, at which point they are sexually mature and ready to give birth.
Spider Mites Place Of Origin
Spider mites are pretty pan global in where they are from. They inhabit most temperate and subtropical regions, with the ideal conditions for their appearance being hot and dry conditions.
While for most seasonal environments this means they suddenly come out in summer, don’t be fooled.
They are still here in winter, just not on your plants, instead they will continue to do what they do but in soil and leave litter, where the temperature is more stable.
They really use their constant reproduction and tiny size to move from one place to the next.
Maybe you accidentally walked into their webbing and got some on your shirt, maybe they traveled with plants from store to store, maybe they simply walked and got lucky.
In any case, their size means that we often don’t notice them until it is too late.
How To Know You Have A Spider Mite Infestation?
There are a few ways to identify a mite infestation without actually seeing the mites themselves, with most of them involving the plant telling you:
Discolored Or Droopy Leaves
Calathea plants have quite distinctive waxy leaves.
If you notice any difference in their color – like they have turned white instead of being green – or that they can no longer hold themselves up – rather they droop down – then you probably have a mite infestation feeding on them.
If you see small, yellowish dots start to appear, then search around the plant to find the mites. At this point, there is still time to save the leaf.
If you are finding spider-like webbing on the plant, but softer and not as intricate on the plant, then a mite has probably got to it.
Spider mites weave webbing to keep themselves safe from predators, more as a shield than a trap, like spiders do.
This is one of the biggest clues to tell that you have a mite problem.
The Leaves Aren’t Closing At Night
Calathea plants have leaves that will routinely open in the morning and close when nightfall comes.
While there are many reasons a Calathea won’t close its leaves at night, one of them could be that spider mites are stopping it.
To be able to close its leaves, Calathea plants need to be at peak operation. If something is feeding heavily on it, then it will not have the strength to do this.
Saving Your Calathea From Spider Mites
Unfortunately, spider mites are a bit like the common cold. They spread quickly and appear out of nowhere, which makes them hard to predict and prevent.
However, there are ways to deal with them once they are here and many of them are very easy to do:
Separate The Infested Plant From The Rest
This isn’t so much for the infested plant’s benefit, but for the rest of your plants.
Mites travel very fast despite their tiny bodies and legs, if you do not separate them, you may lose your whole garden, not just one plant.
Check every other plant for signs of mites after the Calathea has been moved, and then keep it separate for thirty days at the very least.
Prune The Affected Areas Of The Plant
To save the entire plant, it may be necessary to sacrifice parts of it. Many of the leaves on the Calathea that are dead or damaged need to be cut off at the node near the stem.
These leaves are probably covered in mites and are actually holding your plant back.
The plant is trying to keep everything going, but if it is putting energy into trying to save dead or dying leaves, it wastes energy recovering and fighting off the mites.
Once you have taken the leaves off, seal them in a separate closed bag and dump it in a bin far away from your plants.
Then, wash any tools you used to prune the plant. Mites are tiny and tricky, so they may have hitched a ride on these.
Wiping Or Washing Your Plant
Once you have completed the damage control, it is time to deal with the mites themselves.
This should be done immediately after pruning, as otherwise the mites will reproduce very quickly, and you will have to repeat the pruning stage.
Get a damp cloth with some warm, slightly soapy water. Wipe the entire plant down thoroughly with the cloth.
The soap will stop any mites finding a purchase on the leaves and allow you to get rid of them quickly.
Once you have wiped everything down, take the plant to the sink and tilt it slightly in the basin, just under the tap. Now give the plant a rinse, making sure it is tilted appropriately.
The water will get any mites you missed, and the tilt will mean they go down the drain and not into the soil in the pot, where they will just reappear from later.
Using Insecticidal Soap
While a dishwashing or normal soap can aid in getting rid of mites, it won’t kill them.
As such, after you have completed the wiping and washing of the plant, it might be worth your time investing and using an insecticidal soap.
They are quite cheap and not toxic to the plant, but quite devastating to the mites.
It basically disrupts the mite’s ability to perform anaerobic respiration and slowly suffocates them to death.
Making this soap into a spray and giving your plant a spritz is a great way to deal with any mites that manage to survive your washing of the plant itself.
However, before use, make sure that these particular soaps are what it says it is.
Spray on the area of a leaf and wait a day to see whether it has an adverse effect on the plant itself.
If you see browning or any spotting where you sprayed the soap, don’t use the soap as it is. You can either dilute the solution, or you may have to buy another insecticide.
Once you have got an insecticide soap that works for you, it’s time to tackle the mites head on.
Take your spray and spray the plant’s stem, upper and underside of the leaves every four to seven days during the plant’s quarantine from the other plants.
The morning or evening time is best, as you don’t want the spray to evaporate quickly.
Once a few hours have passed since you sprayed – maybe 2 to 3 – rinse or wipe the soap off the plant, along with the unlucky mites.
What is neem oil? Well, neem oil is a natural and organic way to deal with insect, fungal, and mite infestations.
The oil is made from the seeds of the neem tree, which grows within the Indian subcontinent and along the southern reaches of Iran.
For generations, it has been a safe alternative to using commercial pesticides, with many common pesticides using neem oil as an active ingredient.
While it does not kill the mites outright, it will stop the hormone production that regulates their need to eat and reproduce, basically starving them of food and new mites for the growing colony.
It may take a little longer than other types of pesticide, but it is much safer and just as effective.
As with the soap before, spray a patch on a leaf before using it, to see if it will damage the plant, and then wait a day to see the results.
The oil comes in a ready to spray bottle or as a concentrated dose that you can dilute in water.
Yet, you should never directly touch or inhale neem oil, as it is a skin irritant to humans. As such, please use gloves.
As before, spray the stem, upper and lower sides of the leaves and then take the plant out of direct sunlight until the oil has completely dried.
Spray the plant with the oil every fourteen days for a normal infestation, or every seven days for a huge one.
Rinse the plant daily to get rid of the oil and any mites that might have gotten caught in it.
Surprisingly, ladybugs are one of those key stone species that keep other insects from infesting everything.
Yes, these seemingly cute little insects are actually deadly predators of the bug world in the same vein as spiders and dragonflies.
Yet, their key source of food is actually the very pest-like insects that destroy plants and crops, like aphids and mites.
It may make people uncomfortable to release a bunch of predatory insects into a garden or, god forbid, indoors, but if you have a major mite problem, they might be your only answer.
Even though it is not a modern way of dealing with pests, it is an incredibly effective one.
One ladybug can eat nine mites an hour and up to 100 a day. Considering mites can only lay 20 eggs a day between them, the effect is devastating on mite populations.
You can buy ladybugs at garden centers or online and usually for a large indoor space, a package of 1500 is enough. For a large garden, you might want to purchase a few more.
Before you release them, they will need some water and food.
They have probably been traveling for a day or so with none, so put a damp, but not wet sponge and a couple of raisins in the container they are in.
While they feed, make sure that the area you want to release them into is contained and controlled.
Maybe put the affected plants in an area where you can hang sheeting and that has a window.
Once you have contained the area, make sure the plant is sprayed down with water to keep the bugs hydrated, and then release them into the area in the morning or evening.
The ladybugs will head straight for the mites, due to their odor and the plant damage they can see, and begin chowing down.
Once you have released them, wait a few hours or overnight and go back to see how things are going.
The ladybugs are sure to have congregated at the window, so now you can either release them or gently scrap or vacuum them back into a container for later use.
Releasing them once a week would be perfect for dealing with the mites, just make sure to feed the ladybugs and, if you need to store them, put them in a dark cool place or in the fridge.
If you have used an insecticide or neem oil, the ladybugs will die.
There are a couple of ways to prevent a spider mite infestation, and they are actually relatively easy to do:
Isolate your Calathea, as we mentioned earlier, so your other plants are affected when it is infected.
Do this for thirty days, so the mites can go through a lifecycle, and you can see whether it is truly infected or not.
Clean Your Plant
Wiping down the leaves and stems of the plant regularly will keep it free of pests and potential problems in the future.
Keep The Humidity High
Spider mites love hot, dry weather and hate humidity, but Calatheas love humidity. Keeping it humid will keep your plant happy and mite free, however don’t let your plant sit in water.
Check The Soil Regularly
Weeds and other invasive pests will lurk in the soil. Checking it regularly can keep your plant healthy and happy.
Calatheas are beautiful plants, but they are very prone to spider mite infestations.
Their home is not really plagued by mites as much as other places, and so they struggle to cope with them.
Yet, if you use the tips and tricks we have laid out for you in this article, you should have no problems spotting potential problems, dealing with an infestation, and creating a system to prevent one in the future.