Hi everyone, I'm really hoping someone can help me out! I've recently been struggling with fungus gnats (and possibly thrips or spider mites too but I'm not entirely sure) on a lot of my house plants. I have been using some pesticide spray and was wiping the leaves of my plants most days. It seems most of them have recovered but my favourite Calathea 'Beauty Star' seems to be struggling - the leaves are curling one at a time and then turn yellow and die. I've tried bottom watering and misting, and it's not kept in direct sunlight either. I use tap water that's been left to stand for several days or rain water if I can collect some. I'm really not sure what to do or how to help it?!

I had a huge problem with fungus gnats...try mosquito bits and sticky traps, it's the only thing that worked. I would take that plant out, shake off all soil from roots, and repot. It's possible the gnats have gotten to the roots, so make sure the roots look healthy.

Your problem is more likely to be lack of adequate humidity

Gina1960 said: Your problem is more likely to be lack of adequate humidity

How would I increase the humidity? I've been putting my plant in the bathroom whilst I shower (like in the photos shown) but is there anything else I can try? Thank you for your reply😊

lalaland4803 said: I had a huge problem with fungus gnats...try mosquito bits and sticky traps, it's the only thing that worked. I would take that plant out, shake off all soil from roots, and repot. It's possible the gnats have gotten to the roots, so make sure the roots look healthy.

Thank you so much for your reply! I shall have a look at the health of the roots tomorrow, fingers crossed they're healthy enough for the plant to recover!🤞🏻

Both misting and putting it in the shower area does not increase the ambient humidity. It only increases it a little for a while.

Are you watering consistently? If so, is this a new plant? If its a new plant it's coming back from shock.

The leaves might be reacting to the fungicide or pesticide or whwatever (I forgot)
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sedumzz said: Both misting and putting it in the shower area does not increase the ambient humidity. It only increases it a little for a while.

Are you watering consistently? If so, is this a new plant? If its a new plant it's coming back from shock.

The leaves might be reacting to the fungicide or pesticide or whwatever (I forgot)
.

I've had this plant since September 2021 and it was doing super well until the fungus gnat problem which came in January 2022 - I was watering it regularly before then, just whenever the top few inches of soil started to feel dry, but because of the fungus gnats I read you're meant to let the soil dry out to kill the gnats eggs? I have used sticky traps to catch the adult flies but they still haven't fully gone. I've not used the pesticide spray on the leaves for the past week or so and I've got several other different calatheas which have seemed okay with the pesticide which I bought from the same plant shop that have sold me all my plants! Just worried that despite bottom watering it doesn't seem to be unfurling and I don't want to lose this plant! Thank you for your reply and any other suggestions would be super helpful😊

Actually , are the black undersides an actual characteristic of this species? If not , it's might Be cold damage ?

All Calathea have dark undersides. This is an evolutionary characteristic that they developed while living on the forest floor of the rainforest, where only about 2% of the ambient light filters down through the canopy and understory. The colored pigments in the leaf undersides have specialized cells that allow the plant to pick up and photosynthesize 'green light', the wavelenth of light that bounces up off the forest floor. To increase the humidity adequately around your plant, especially in the dry winter months, a cheap cool mist vaporizer or humidifier set up in the shower to make a mist chamber would be very beneficial.

Gina1960 said: All Calathea have dark undersides. This is an evolutionary characteristic that they developed while living on the forest floor of the rainforest, where only about 2% of the ambient light filters down through the canopy and understory. The colored pigments in the leaf undersides have specialized cells that allow the plant to pick up and photosynthesize 'green light', the wavelenth of light that bounces up off the forest floor. To increase the humidity adequately around your plant, especially in the dry winter months, a cheap cool mist vaporizer or humidifier set up in the shower to make a mist chamber would be very beneficial.

I was wondering about the black coloring :-)
I find it cool the underside colors. They can be used to diagnose if teh plant has too much light, at least for Marantas.

The phenomenon called 'praying' where the leaves turn up is also an evolutionary survival mechanism. Since only between 2-5% of the rain that falls on a rainforest actually makes it to the forest floor, the leaves of the Calathea alliance have developed this uplifting of the leaves to funnel any rain that falls down directly to the root ball